Seminars and Colloquia at ESO Garching and on the campus

A non ambiguous definition of stellar radial velocity (RV) is non trivial. Early comparison between astrometric and spectroscopic RVs revealed only a qualitative agreement and hint to potential quantitative differences between them. We compare for the first time in detail spectroscopic and astrometric RVs for stars of the Hyades open cluster.

Astrometric RVs are available for the Hyades’ stars, based on Hipparcos and on the first Gaia data release. We obtained HARPS spectra for a large sample of Hyades stars, and we homogeneously analysed them, either by applying a zero point correction deduced from solar observations and equal for all stars, or by correcting each star for the convective shifts in the stellar atmosphere computed theoretically from 3D atmospheric models. After cleaning the sample from binaries, RV variables, and outliers, 71 stars remained.

The distribution of the RV difference (spectroscopic – astrometric) is skewed and possibly double-peaked, and it depends on the star right ascension. This is consistent with the Hyades cluster rotating at 43±10 m s−1pc−1.We find that the spectroscopic radial velocities published in literature have a mean offset of 689 m s−1.We detect in the two single cluster giants clearly Gravitational Redshift in perfect agreement with predictions.The mean difference between spectroscopic and astrometric RV is of −33 m s−1 and the median is of −16 m s−1 when considering the Gaia-based RVs (corrected for cluster rotation) and the theoretical spectroscopic RV corrections, and of −85 m s−1 and +48 m s−1 when considering the Hipparcos and the empirically determined zero correction.  Thus it is possible to reach accurate RV measurements.

We finally discuss the phenomena that can influence the astrometri and spectroscopic RVs, such as cluster expansion, stellar activity, general relativity, Galactic potential; clusters within the reach of current telescopes are expected to show differences of several hundreds m s−1, depending on their position in the Galaxy, but will not have precise enough astrometric RV.

Henri Boffin will present his latest paper on Kepler binaries:

http://adsabs.harvard.edu/abs/2017arXiv171200022M

Nuclear star clusters (NSCs) are found in at least 60% of galaxies, but their formation path is still unclear. NSCs could form from infalling gas at the galactic centre or might build up from in-spiraling globular clusters (GCs). In the first scenario, the NSC should show high angular momentum and higher metallicities from subsequent star bursts while in the second scenario, the NSC should reflect the low angular momentum and low metallicities of the surroundingGC population. To constrain these scenarios, we use observations taken with the Multi Unit Spectroscopic Explorer (MUSE) of three early-type galaxies in the Fornax galaxy cluster to study the kinematic and stellar population properties of their GC systems.I will present my current work on the kinematic analysis of the three galaxies by comparing the integrated light to GCs and planetary nebulae as point source tracers.

In recent times modern cosmology has witnessed a natural progression: Starting from observations of the homogeneous expansion dynamics with supernovae of type Ia and linear perturbations in the CMB the field is now focussing on studying linearly evolving structures in the distribution of galaxies.

A natural next step is cosmology with nonlinearly evolving structures, making up a large fraction of the signal in optical surveys.

In this talk I will present a new approach to studying the non-linear evolution of cosmic structures in observations via large scale Bayesian methods. This new technology infers 3D initial conditions from which observed structures originate, maps out non-linear density and velocity fields, and provides dynamic structure formation histories including a detailed treatment of uncertainties. Data application provides an unprecedented view on the dynamical evolution of structures surrounding us. This will be exemplified by highly detailed dynamical reconstructions of the Coma cluster and Sloan Great Wall but more generally of the entire large scale structure in the Nearby Universe.

Cataclysmic variables (CVs) are interacting binaries composed of a white dwarf undergoing stable mass transfer from (usually) a low-mass main sequence star and they are expected to exist in non-negligible numbers in globular clusters (GCs) that are natural laboratories for testing theories of stellar dynamics and evolution. In the first part of this talk, I will describe two methods for investigating CVs in GCs, which are direct N-body integrations and Monte Carlo approach. I will then explain why the Monte Carlo approach is the most convenient for investigating exotic objects in GCs. In the second part, I will present the main aspects related to our understanding regarding GC CV populations based on the analysis of MOCCA (Hypki & Giersz 2013) numerical simulations performed by Belloni et al. (2016,2017a,2017b) and Hong et al. (2017). Emphasis will be given to the main differences in present-day CV properties due to dynamics in comparison with CVs in non-crowded environments. Finally, I will discuss how good are the agreements with respect to recent searches for CV candidates in four specific GCs, namely NGC 6397 (Cohn et al. 2010), Omega Cen (Cool et al. 2013), NGC 6752 (Lugger et al. 2017), and 47 Tuc (Rivera-Sandoval et al., sub. to MNRAS).

In order to understand the nature of dark matter, reliable and comprehensive dynamical studies of dark matter dominated galaxies are of utmost importance. Local dwarf spheroidal (dSph) galaxies are the perfect objects for those kind of studies. So far, most approaches have assumed spherical symmetry on their dynamical models; however, we know that the stellar component of these galaxies is not spherical. Assuming spherical symmetry might produce a bias in their mass measurements. Here we present a generalisation, utilising axisymmetric Jeans equations, in order to model their internal dynamics and velocity dispersion profiles. This approach allows us to determine the mass distribution of the underlying axisymmetric stellar system in general, and apply it into dSph galaxies. Utilising mock catalogs, we have analysed the parameter space of the dark matter halo model. If only line-of-sight velocities are used, the halo parameters show a significant degeneracy, which is strongest between the meridional anisotropy and the axis ratio of the halo. This degeneracy cannot be broken with line-of-sight velocities alone, even if the sample size is increased or if the analysis is done utilising a discrete approach rather than the usual binning of the data. We have applied our axisymmetric Jeans models to the Local Group dSph galaxies Fornax and Sculptor, the ones with the largest datasets available in the literature, and conclude that even if this degeneracy limits our constraints on the shape of the dark matter halo, the mass within the half-light radius is still a robust result.

In this presentation I will provide an overview of the principle developments in the field of long and short gamma-ray bursts (GRBs) and their host galaxies over the past two decades. I will show how near-infrared observations of the afterglows of short and long GRBs have been pivotal in developing our understanding on the underlying progenitor, largely aided by the rapid and accurate afterglow positions available with the GRB Swift mission. I will also discuss the use of long GRBs as probes of the high redshift Universe, and in particular how their broadband and bright afterglows provide a powerful probe of the interstellar conditions within their high-z, star forming host galaxies. I will also discuss the selection effects present in GRB and host galaxy samples, and how these have affected our view on the host galaxy properties of long GRBs.

The interstellar medium is heated and ionized by radiation, by stellar winds, and finally, by supernova explosions of massive stars. These processes are often correlated in space and time, generating superbubbles filled with hot thin plasma with sizes of typically 100 −1000 pc. Supernova remnants and superbubbles can be studied best in softX-ray line and continuum emission, since the plasma in their interiors is very hot (10 6 - 10 7 K), while there are also a few cases in which the emission from non-thermal particles dominates that of the thermal gas. I will talk about our studies of the hot interstellar medium in theMilky Way and nearby galaxies. I will discuss the physics of the hot plasma, the evolution and energetics of supernova remnants and superbubbles, and their impact on star formation.

At the heart of interpreting starlight, infrared and radio continuum (all typically dominated by massive stars) in terms of star-formation rate (SFR) and stellar mass in individual galaxies or averaged over cosmological volumes, the stellar initial mass function (IMF) is often described as a nearly-universal function in the Galaxy and nearby galaxies. Classical determinations of the IMFin local galaxies are traditionally made at ultraviolet, optical and near-infrared wavelengths that cannot be adopted for dust-obscured galaxies, and even more so in distant starbursts selected at submillimetre (rest-framefar-infrared) wavelengths, exactly the type of galaxies for which galaxy evolution models often predict an IMF biased towards massive stars.  We bring along the state-of-the-art chemical evolution models with well-calibrated stellar yields, time-delay effects, and various star formation history, combine with abundances of carbon and oxygen isotopologues measured in molecular gas,opening up an unexpected new gate of exploring the IMFs in dust-rich galaxies,especially for those in the early Universe. We will also  discuss the physical origins for the top-heavy IMF in starburst systems, presenting our new ALMA results in a few strongly lensed dusty starbursts at high redshift, and compare them with different types of local galaxies.

Galaxy groups are believed to be important sites of gas pre-processing in galaxies, which in turn impacts their stellar and morphological evolution.  As groups accrete more galaxies, the groups themselves become increasingly poor in neutral atomic hydrogen (HI), and more cluster-like.  Studies of compact groups suggest that gas processing through tidal interactions simultaneously depletes the cold gas in galaxies and contributes to the build-up of the warm-hot intragroup medium that is sometimes detected in X-rays.  We present the results of stacking ROSAT All-Sky Survey images for a large sample of groups for which we have simultaneous HI data from the ALFALFA survey in an attempt to detect the build-up of the WHIM in intermediate mass groups M>10^13 M_Sun, where we begin to see the impact of the group environment on the HI content of their member galaxies.  With HI and X-ray observations together, the goal is to simultaneously trace the recent accretion of galaxies and groups, and build-up of the hot gas reservoirs in groups and clusters.

The discovery of the first extra-solar planet around a main-sequence star in 1995 has changed the way we think about the Universe: our solar system is not unique. Twenty years later, we know that planetary systems are ubiquitous, orbit stars spanning a wide range in mass, and form in an astonishing variety of architectures. Yet, one fascinating aspect of planetary systems has received relatively little attention so far: their ultimate fate.

Most planet hosts will eventually evolve into white dwarfs,Earth-sized stellar embers, and the outer parts of their planetary systems (in the solar system, Mars and beyond) can survive largely intact for billions of years. Studying these systems provides detailed measurements of the bulk composition of rocky exo-planetesimals, the efficiency of planet formation around stars with ~1-8 solar masses,and insight into the architecture of the outer planetary systems around the white dwarf progenitors.

Ultra-diffuse galaxies (UDGs) are a class of low surface brightness (LSB) galaxies with stellar masses typical of dwarfs (M*~10^7-10^8) and large sizes (Rh>1.5kpc) for their luminosity. UDGs are ubiquitous and abundant in nearby galaxy clusters, but their formation mechanism is still unclear. I will review the recent proposals and show that a scenario in which UDGs represent the tail into the LSB regime of the abundant dwarf galaxy populationreproduces their abundance and size-distribution in clusters. I will also expand on an effort to assess the richness of their GC systems. This has shown that most Coma LSB galaxies have GC abundances that are in line with what expected for their stellar mass. A small fraction of systems, however, displays ‘over-abundant’ GC systems. Interestingly, not all of the latter are extended, implying that the physical mechanisms responsible for the large sizes of the UDGs and for the enhanced GC abundances of some cluster dwarfs are not identical.

The physical processes leading to the conversion of gas to stars can be best understood through direct observations of cold atomic and molecular gas, which act as the reservoir for star formation. Considerable progress has been made in mapping the distribution of diffuse gas in the circumgalactic medium of galaxies using absorption from Lyman-alpha and metal lines like Mg II. However, the distribution of high neutral hydrogen column density (N(HI) >~ 10^19 cm^-2) cold (T ~ few 100 K) gas around galaxies is not yet well understood. Such cold gas can be traced via HI 21-cm absorption without being affected by dust and luminosity biases. Hence, with a view to map the distribution of cold HI gas around galaxies, we have carried out systematic surveys of HI 21-cm absorption at both low (z < 0.4) and high (0.5 < z < 1.5) redshifts, using quasar-galaxy-pairs and strong Mg II/ Fe II systems, respectively. The main results from our studies will be presented in this talk.

The stellar initial mass function (the IMF) plays a ubiquitous role in astrophysics, from controlling the metal production by stellar populations, to establish the mass-to-light ratio of galaxies and the rate of their luminosity evolution, to set the strength of gravity sensitive spectral features and much more. Sometimes one appeals to a top-heavy IMF to ease some perceived discrepancy, or to a bottom-heavy one to ease another. In this lecture I will concentrate on a few specific examples,  illustrating the effect of the IMF slope in different mass ranges, near the solar mass as well as well above and below it,  and including issues such as the metal content of clusters of galaxies, the fundamental plane of elliptical galaxies and their integrated spectrum. In a final caveat, it will be emphasized that measuring the IMF from integrated light requires the use tools which, if not perfect, could imprint their defects into the result.

On 17th Aug 2017, a strong source of gravitational waves was detected by theLIGO-Virgo collaboration. The signal lasted for 60 secs and the event was followed just 2 seconds later by a short burst of gamma-rays detected by Fermi and Integral.All sources had consistent sky positions within about 30 square degrees. A fast fading optical and near-infrared counterpart was discovered and studied intensively for several weeks.

I will present the results of this unprecedented discovery, the first electromagnetic counterpart of a gravitational wave source, the first identification of a neutron star - neutron star merger and the first direct evidence of the source and origin of the r-process elements.

I will focus on the ePESSTO team's results, showing that this remarkable transient truly opens up the era of multi-messenger astronomy.

I will give a brief overview of our current understanding of AGN, in particular focusing on the different “pieces of the puzzle”: the central BH, the accretion flow, the torus, outflows, and jets. I will discuss their physical properties and the techniques/bands used to study them.  I will mention also the current open questions and possible way forward.

We have evidence that heavy elements are synthesized and dispersed in cosmic explosions of various types, though the role and contribution of different physical events in forming heavy elements is still unclear. Rapid localization of cosmic explosions now enables us to conduct detailed studies that illuminate thesequestions.

I will present some examples including in particular near-real time spectroscopic observations, that I expect to lead to revolutionize these fields in the coming decade.

The dynamical scaling relations of galaxies -- connecting their luminosity and velocity profiles -- have long been an important source of information about galaxy formation. In this talk I will present a detailed statistical study of four such scalings -- the Tully-Fisher, Faber-Jackson, mass discrepancy-acceleration relations, and Fundamental Plane -- with the aim of inferring the galaxy-halo connection and assessing the validity of current empirical models.

I will demonstrate that the relations provide evidence for correlations of galaxy size and morphology with halo properties at fixed stellar mass, and constrain the scatter of the galaxy-halo connection and the impact of galaxy formation on halo profiles. Finally, I quantify various discrepancies between the data and model predictions, most notably in the relations' intrinsic scatter.

The last two decades since the discovery of the first extrasolar planet have completely revolutionised what we know about planets.  In particular, the unprecedented spatial resolution of the millimetre interferometer ALMA has provided us with high resolution images of protoplanetary discs -- the birth environments of planets.  These are more detailed images than ever before and are giving us clues about the planet formation processes.

Recent ground-breaking observations are hinting towards planets starting to form when protoplanetary discs are young and massive -- so called self-gravitating discs.  In contrast to the standard paradigm for planet formation, these results may now have pushed the likely era of planet formation into the early self-gravitating stage of disc evolution, potentially making this brief phase in a disc’s lifetime more critical for planet formation than previously thought.  One such observation is the Elias 2-27 protoplanetary disc which exhibits strong spiral structures out to approximately 250au. Through the results of recent numerical simulations, I will discuss whether Elias 2-27 could be the first observation of a self-gravitating disc. I will also discuss some evolutionary processes that planets and discs go through once planets form in such young discs.

The frequencies of oscillations observed on a stellar surface carry information about the properties of the stellar interior. Asteroseismology, i.e., the unravelling of this information, has made a huge leap thanks to the photometric observations obtained with NASA' Kepler mission, launched in 2009 to search for planets around other stars. In my talk I focus on the study of red-giant stars, showing a broad range of oscillations, probing both the outer parts and the deep core of the stars. Amongst other remarkable results, this has allowed distinguishing stars according to their nuclear energy source and provided detailed information about the properties of internal rotation in these late stages of stellar evolution.

We will share our experience of teaching at the West African International Summer School for Young Astronomers, held in Ghana this summer and Nigeria in 2015. We will summarize the obstacles faced by West African physics students in pursuing a career in science, and explore how we as professional astronomers could contribute to improving the situation.

Gravitational waves have become a very hot topic in astrophysics since their detection by LIGO in 2015. This means that also possible precursors are in the focus of research – general relativistic research because these objects are either black holes or neutron stars. The 2017 Biermann Lecturer, Masaru Shibata from the Kyoto University, uses numerical simulations and general relativity (or numerical relativity for short) to study the merger of such extreme objects and the properties of both the electromagnetic radiation and gravitational waves emitted during these events.

Radio-loud AGN (RLAGN) tend to reside in the most massive dark matter halos, and have a long history of being used to efficiently identify rich, high-redshift structures (i.e., clusters and protoclusters). Our team contributed to this effort with a targeted 400hr Spitzer program surveying 420 RLAGN (radio-loud quasars and high-z radio galaxies) at 1.3 < z < 3.2 across the full sky: Clusters Around RLAGN (CARLA; Wylezalek et al., 2013, 2014). The CARLA Survey identified 200 cluster candidates at 1.3 < z < 3.2 as 2-8 sigma overdensities of red color-selected Spitzer/IRAC galaxies around the targeted powerful RLAGN. I will present results from our follow-up 40-orbit HST program on the 20 densest CARLA cluster candidates at 1.4 < z < 2.8. We spectroscopically confirm 16/20 distant structures associated with the RLAGN, up to z=2.8 (Noirot et al., 2016, 2017). For the first time at these redshifts, we statistically investigate the star-formation content of a large sample of galaxies in dense structures. We find that massive galaxies are located below their star-forming main-sequence up to z=2. This implies that the massive star-forming end of the (proto)cluster population already followed an accelerated evolution at these high redshifts. We also find an increasing concentration of star-forming members with smaller radii relative to the RLAGN, consistent with a reversal of the SFR-density relation.

I will show that our confirmed CARLA structures represent rich environments comprised of mixed populations, including both evolved, passive, massive galaxies, and galaxies with ongoing star formation. Together, this unprecedented sample of 16 confirmed structures at 1.4 < z < 2.8 constitutes an ideal sample for further statistical investigation of the cluster transition phase, including study of quenching mechanisms

For very heavy quarks, relations derived from heavy-quark symmetry predict the existence of novel narrow doubly heavy tetraquark states containing two heavy quarks and two light antiquarks. We predict that double-beauty states will be stable against strong decays, whereas the double-charm states and mixed beauty+charm states will dissociate into pairs of heavy-light mesons. Observation of a new double-beauty state through its weak decays would establish the existence of tetraquarks and illuminate the role of heavy color-antitriplet diquarks as hadron constituents.

The exoplanet studies were born on the border of two fields - those of binary star and the Solar system studies. I will review the history of the exoplanet research, the latest results, and will summarize the most important questions that have remained unanswered.

The Dark Energy Survey has combined analyses of galaxy clustering andweak gravitational lensing two-point correlation functions in itsfirst year (Y1) of observations. This combination of measurementsprovides information on the amplitude of density fluctuations(S8=0.794+0.029-0.027) and the dark energy equation of state(w=-0.80+0.20-0.22) that is competitive and consistent with Planck CMBdata. When joint with probes of cosmic geometry, it yields the bestmeasurement of these parameters to date. I will review these resultsand the technical advances that facilitated them. In addition, I willalso present a novel probe that provides a DES lensing view of thefull PDF of the matter density field.

We will informally discuss the recently announced kilonova event associated with the gravitational wave GW 170817, with particular emphasis on the ePESSTO collaboration paper.

Gravitational waves have become a very hot topic in astrophysics since their detection by LIGO in 2015. This means that also possible precursors are in the focus of research – general relativistic research because these objects are either black holes or neutron stars. The 2017 Biermann Lecturer, Masaru Shibata from the Kyoto University, uses numerical simulations and general relativity (or numerical relativity for short) to study the merger of such extreme objects and the properties of both the electromagnetic radiation and gravitational waves emitted during these events.

SLODAR-type methods use spatial correlations from observations of two guide stars to estimate the vertical turbulence profile. These methods rely on the Kolmogorov/von Kármán turbulence model, but the turbulence statistics can deviate from these models, especially close to the ground. We present a possible method for identifying non-Kolmogorov turbulence models close to the ground from AO telemetry using a SLODAR-type method.

I will discuss our recent results studying light curves of hydrogen-rich supernovae during the first few days after explosion. The first days of emission encode important information about the physical system, and it is possible to relate the early-time light curve to the radius of the progenitor star by using shock-cooling models. I will show the first systematic application of these models to data from the Palomar Transient Factory (PTF). I will also discuss improved observing strategies to obtain more constraining results in the future. One important question is the effect of circumstellar material on the light curves, motivating future systematic spectroscopic sequencing of these events.

To this end, we have designed a new medium resolution UV-VIS spectrograph. The Multi-Imaging Transient Spectrograph (MITS) is the R~4500 UV-VIS arm of the Son Of X-Shooter (SOXS) spectrograph proposed for ESO’s 3.6 m New Technology Telescope. Our design divides the spectrum into several channels, allowing optimization for each narrow part of the spectrum. We estimate a 50-100% improvement in throughput relative to a classical 4-C echelle design. Our design has passed a preliminary design review and is expected on the telescope in 2021.

Variational methods provide tractable approximations to probabilistic and Bayesian inference for problems where exact inference is not tractable or Monte Carlo sampling approaches would be too time consuming. The method is highly popular in the field of machine learning and is based on replacing the exact posterior distribution by an approximation which belongs to a tractable family of distributions. The approximation is optimised by minimising the Kullback—Leibler divergence between the distributions. In this talk I will discuss applications of this method to inference problems for stochastic processes, where latent variables are very high- or infinite dimensional. I will illustrate this approach on three problems: 1) the estimation of hidden paths of stochastic differential equations (SDE) from discrete time observations, 2) the nonparametric estimation of the drift function of SDE and 3) the analysis of neural spike data using a dynamical Ising model.

The Panchromatic Hubble Andromeda Treasury is an HST multicycle program to image the north east quadrant of M31 to deep limits in the UV, optical, and near-IR. The HST imaging has resolved the galaxy into over 150 million stars (comparable to ~1/2 the number of stars in SDSS), all with common distances and foreground extinctions. As its legacy, this survey adds M31 to the Milky Way and Magellanic Clouds as a fundamental calibrator of stellar evolution and star-formation processes for understanding the stellar populations of distant galaxies. I will briefly describe the survey strategy, data reduction, and key data products. I will then highlight new work using the NIR stellar populations to constrain the large scale properties of the cold ISM, with 25 pc resolution. These new maps offer the highest resolution available inM31, and point to surprising challenges facing models of dust emission.

Lithium, fragile and scarce, sensitive and primitive, is one of the most complicated elements in astrophysics. Its abundance in stars, in both the main sequence phase and the giant branch phase, has plagued our current understanding of cosmology, stellar evolution, and metal sources of the interstellar medium. I will discuss problems and puzzles that Li introduces in astrophysics, including cosmological Li problem, Li-rich giants problem, Li problem in the Sun, nucleosynthesis of Li production, and Interstellar Li content, then focus on the Galactic Li evolution.

Gravitational waves have become a very hot topic in astrophysics since their detection by LIGO in 2015. This means that also possible precursors are in the focus of research – general relativistic research because these objects are either black holes or neutron stars. The 2017 Biermann Lecturer, Masaru Shibata from the Kyoto University, uses numerical simulations and general relativity (or numerical relativity for short) to study the merger of such extreme objects and the properties of both the electromagnetic radiation and gravitational waves emitted during these events.

Throughout history, the light from stellar populations has been the dominant way we determine the properties of galaxies. The stellar initial mass function (IMF) parameterises the number of stars formed as a function of their mass, and is commonly assumed to have a universal form regardless of the star forming environment. Recently the universality of the IMF has become a hotly debated topic in astrophysics, as evidence for the detections of real variations are becoming substantial. In this work, I present constraints on the high mass slope (m∗ > 1M⊙) of the IMF using Hubble Space Telescope (HST) observations of three nearby dwarf irregular galaxies that are resolved into individual stars. My approach compares observed Hα flux and the luminosity distribution  of main sequence stars  to the expectations from simulated populations with varying IMFs. Where possible, the two methods are  combined to derive tighter constraints. Finally, I determine the local Kennicutt-Schmidt star formation law to quantify how star formation and the IMF are correlated.

We briefly review the recently  developed tensor renormalization group method for spin and gauge models. We discuss approximate solutions of the fixed point equation for the two-dimensional Ising model. We discuss the analysis of the images of stochastically generated loop configurations (“worms”) for this model near the critical temperature, by using RG adapted machine learning  methods. We show numerical evidence supporting the conjecture that the leading eigenvalue of the Principal Component Analysis of the worm images has a logarithmic divergence at the critical temperature. We discuss the correspondence between the two approaches under coarse graining procedures.

We will discuss emission line processes such as forbidden lines (collisional processesetc), recombinations and fluorescent lines. Practical examples of modeling NLTE atoms and looking at spectra to derive properties will be demonstrated.

In this presentation, Jorge will share his experience as an amateur astronomer with the Excellence Cluster's CCD camera and an 8-inch telescope with altazimuthal mount. What is feasible with a small telescope? What are its limitations? Jorge will share his experience in astrophotometry, present his analysis of variable stars and show astrophotographic images.

It is generally accepted that the distribution in colour and magnitude (temperature and luminosity) of the Pre MainSequence (PMS) objects in the Orion Nebula Cluster (ONC) shows an intrinsic spread. At least two are the interpretations of such observed spread:1) a genuine spread of the ages of few Myr, inconsistent with that of a coeval stellar population and in agreement with a star formation activity lasting between 1.5 and 3.5 Myr; 2) the spread in temperature and luminosity is a consequence of the accretionhistory taking place at the early stages of the formation of the stars. Recent results obtainedwith multi-band optical photometry with OmegaCAM@VST indicate the presenceof 3 discrete populations of PMS in the ONC. I will discuss how discreteness might prompt a revised look at the formation mode and early evolution of stars in the ONC.

Kazuki will present the recent study on natural and unnatural supersymmetry (SUSY) in light of the proton decay and gauge unification. He will show that the low-energy SUSY mass spectrum is linked to the proton decay via the unification scale. Future nucleon decay experiments will provide a non-trivial upper bound on the superpartner masses. We also show that the mirage mediation provides a consistent picture of natural SUSY. For unnatural SUSY, we present a systematic study on split SUSY and predict a unique spectrum, which could be around the corner of discovery.

Kazuki is a Cluster guest. Local host: Andreas Weiler (TUM)

Gravitational collapse during the Universe's first billion years transformed a nearly homogeneous matter distribution into a network of filaments - the Cosmic Web - where galaxies form and evolve. Because most of this material is too diffuse to form stars, its study has been limited so far to absorption probes against background sources. In this talk, I will present the results of a new program to directly detect and study high-redshift cosmic gas in emission using bright quasars and galaxies as external "sources of illumination’’. In particular, I will show results from ultra-deep narrow-band imaging and recent integral-field-spectroscopy as a part of the MUSE Guaranteed Time of Observation program that revealed numerous giant Lyman-alpha emitting filaments extending up to several hundred kpc around quasars and bright galaxies. I will discuss how the unexpectedly high luminosities of these systems, together with the constraints from Helium and metal extended emission, represent a challenge for our current understanding of cosmological structure formation. In particular, I will show that current observations suggest that a large amount of “cold" and dense gaseous “clumps" should be present around high-redshift galaxies and I will present our first attempts to understand the origin and nature of these structures using high-resolution hydrodynamical simulations.

For very heavy quarks, relations derived from heavy-quark symmetry predict the existence of novel narrow doubly heavy tetraquark states containing two heavy quarks and two light antiquarks. We predict that double-beauty states will be stable against strong decays, whereas the double-charm states and mixed beauty+charm states will dissociate into pairs of heavy-light mesons. Observation of a new double-beauty state through its weak decays would establish the existence of tetraquarks and illuminate the role of heavy color-antitriplet diquarks as hadron constituents.

Information field theory (IFT) describes probabilistic image reconstruction from incomplete and noisy data. Based on field theoretical concepts IFT provides optimal methods to generate images exploiting all available information. Applications in astrophysics are galactic tomography, gamma- and radio- astronomical imaging, and the analysis of cosmic microwave background data. A novel IFT-based gamma ray sky image derived from data of the Fermi-satellite provides insights into the high energy properties of the Milky Way.

The Excellence Cluster Universe organizes the Research Area C Science Day. Experimental as well as theoretical Cluster scientists and students who are active in the field of "What are the phase transitions in the early Universe?" come together to present current research results and developments.

Organizers: RA-C leaders Stefan Schönert (TUM) and Thomas Kuhr (LMU) and the team of the Excellence Cluster Universe

The Bayesian approach has been the standard one in cosmology for the analysis of all major recent datasets. I will present a Bayesian approach to two open issues. One is the tension between different data sets and in particular the value of the Hubble constant inferred from CMB measurement and directly measured in the local Universe. It can be used as a tool to look for systematic errors and/or for new physics. The other one is about neutrino mass ordering. Cosmology, in conjunction with neutrino oscillations results, has already indicated that the mass ordering is hierarchical. A Bayesian approach enables us to determine the odds of the normal vs inverted hierarchy. I will discuss caveats and implications of this.

Recently, the idea of low-energy supersymmetry (SUSY) as a solution to the hierarchy problem has been challenged by the null results of SUSY searches at the LHC. However, SUSY has another important motivation, gauge coupling unification.  Kazuki will review this old idea and find the condition on the mass spectrum that allows precise gauge unification in the Minimal Supersymmetric Standard Model (MSSM). Combining this condition with other considerations from model building, we argue that gluinos should be within the reach of the LHC or future 100-TeV colliders.

Kazuki is a Cluster guest. Local host: Andreas Weiler (TUM)

As usual we will offer fruits, snacks and soft drinks in the lounge area.

Due to the limitations of current astronomical instrumentation and data reduction techniques, the Ultra-Low Surface Brightness (ULSB) universe,  which lies over two orders of magnitude below that of the sky background , is one of the last niche that remains to be explored in observational parameter space. So far, the first pioneering observations using small telescopes and telephoto lens have revealed  a wealth of stellar tidal streams and shells, diffuse stellar systems and a possible hitherto unknown type of galaxies (ultra-diffuse galaxies) whose properties could be  different from those at brighter levels. In this talk, I'll discuss this topic and our deep exploration of the interaction of the Magellanic Clouds using telephoto lens.

Neutron stars contain some of the densest matter in the known universe, with the maximal density in their cores greatly exceeding nuclear matter saturation density. Despite the fact that the theory governing the properties of neutron star matter - Quantum Chromodynamics - is well understood, obtaining accurate first principles predictions for the observable characteristics of neutron stars is surprisingly hard. In my talk, I will describe recent advances in this direction and in particular explain, how information about the equation of state of high-density deconfined quark matter, obtained using resummed perturbative QCD, can significantly aid solving the neutron star mystery.

We would like to discuss with you the time allocation process at ESO – how does (should) it support the scientific goals of the community? We will briefly review the outcomes of the Time Allocation Working Group, look at what other observatories are doing (HST, Gemini, …) and present fun facts about request statistics and OPC gradings.

With over 600 specialists in financial and risk management for banks, insurers, corporates and asset managers, d-fine is one of Europe's leading consulting firms. As an international company with offices in Frankfurt, Munich, Zurich, Vienna and London, we are equally at home advising major global banks, medium-sized corporates, international insurance groups and small hedge funds. d-fine has amassed tremendous experience over the course of hundreds of projects ranging from strategic consulting and methodology development through to process design and the implementation of solutions on the IT side. As such, we cover the entire range of services expected of a modern consulting firm. In the lecture “Physicists in the area of risk & finance”, Dr. Matthias Aicher will talk about d-fine, provide examples of the daily work at a consultancy and explain why physicists (m/f) have ideal prerequisites for a career at d-fine.

Bars are common in the local Universe, approximately ⅓ of the nearby disc galaxies host strong bars. However, the role of bars in the evolution of their host galaxies is still uncertain. I will present the results of a multi-component (disc+bar and disc+bar+bulge) and multi-wavelength (SDSS ugriz) image decomposition on what is currently the largest sample of local galaxies with strong bars (~3,500 barred SDSS galaxies), selected using Galaxy Zoo morphologies. Measuring the properties of these galaxies reveals differences in the colours of the components of the barred galaxies and a similar mass-matched sample of galaxies without bars, suggesting that bars can lead to the quenching of star formation by driving gas to the galaxy centres, as shown by some simulations.

I will also show a curious sample of low mass galaxies with a bar that is offset from the disc, which I identified in the sample of barred galaxies (Kruk et al. 2017). It is hypothesised that these offsets arise in galaxy interactions, but a nearest neighbour search does not produce a correlation between the offsets and companions. I will also discuss alternative scenarios that can give rise to the offsets.

Finally, I will show the new Zooniverse Project Builder, that allows anyone to build their own citizen science project in just a few minutes!

The mass of a protoplanetary disk limits the formation and future growth of any planet. Masses of protoplanetary disks are usually calculated from measurements of the dust continuum emission by assuming an interstellar gas-to- dust ratio. To investigate the utility of CO as an alternate probe of disk mass, we use ALMA to survey 13CO and C18O J = 3–2 line emission from a sample of 93 protoplanetary disks around stars and brown dwarfs with masses from 0.03 to 2 MSun in the nearby Chamaeleon I star-forming region. Gas masses for disks are then estimated by comparing the CO line luminosities to results from published disk models that include CO freeze-out and isotope-selective photodissociation. Under the assumption of a typical interstellar medium CO-to-H2 ratio of 10−4, the resulting gas masses are implausibly low, with an average gas mass of ∼0.05 MJup as inferred from the average flux of stacked 13CO lines. The faint CO line emission may instead be explained if disks have much higher gas masses, but freeze-out of CO or complex C-bearing molecules is underestimated in disk models. CO emission lines will only be a good tracer of the disk mass when models for C and CO depletion are confirmed to be accurate.

Planetary systems form in circumstellar disks around young stars in the first few Myr of stellar evolution. The physical and chemical condtions of disks determine the properties and architecture of planetary systems at birth. Understanding these properties and how they evolve with time during the planet formation process is thus critical to understand thediversity of planetary systems.

In Part I, I discussed the basic theory of disk formation and evolution and the constraints from (mostly) millimetre observations of the dust emission. In Part II, I will discuss the observational properties of the gas in the outer disk, the gas-dust interaction and the growth of dust into pebbles and the first steps of planet formation.

Medium-band photometric surveys, such as COMBO-17, COSMOS and ALHAMBRA, have shown to have the ability to unveil unique information on galaxy evolution, from the near to the distant universe. Ongoing and upcoming large narrow-band surveys will push this further, providing effectively a low-resolution spectra for every pixel of the sky observed. In this talk Silvia will present two large photometric surveys, J-PLUS and J-PAS, carried out at the OAJ observatory, a dedicated facility in continental Spain. J-PLUS, which has already observed few hundreds of square degrees, is scanning the sky with twelve filters, a carefully chosen mix of broad bands and narrow-band filters, able to capture unique galaxy spectral features. She will present the first science verification results, from the IFU-like analysis of local galaxies, to the selection of rare high-redshift emission galaxies and quasars. Silvia will then present forecasts for the J-PAS survey, which will soon start to observe thousands of square degrees with 54 narrow-band filters covering the entire optical range. Its high spectro-photometric resolution, the wide area covered and the unprecedented depth, will make J-PAS a very powerful tool to unbiasedly study the diversity of galaxies across cosmic time, as well as performing complementary cosmological experiments.

Silvia is a Cluster guest. Local host: Mara Salvato (MPE)

First of all, I shall give an overview on the research status about stellar magnetic activity and exoplanetary systems at Yunnan Observatories. Then, some more detailed results derived during recent years will be introduced. For stellar activity, I shall talk about the study on chromospheric and photospheric activities by using high-resolution spectroscopy, magnetic field by using Zeeman Doppler imaging method. For exoplanetary systems, I shall introduce the study on wide field transit survey project, TTV follow-up observations. Finally, the prospects in the near future will be given.

Muon Anomalous Magnetic Moment is one of the most precisely measured quantities in modern physics. Its measured value, known to 0.5 10^{-6} precision, is larger than the theoretical prediction in the Standard Model by almost 4 standard deviations. We discuss various aspects of the problem and explain how precise measurements of the low energy e+e- into hadrons come into play.

As usual we will offer fruits, snacks and soft drinks in the lounge area.

Simon is a Cluster guest. Local host: Stephan Paul (TUM)

At the peak of star formation (z=0.5-3), an important yet hard-to-constrain measurable is the metal gas content of galaxies, a side-product of the evolution of massive stars, and the origin of rocky planets like the earth. At the same time, high-energy source (AGN, GRB) emission is absorbed by this gas along the observers line-of-sight. Therefore it could be interesting to indirectly do galaxy tomography with these column densities. We performed a survey of afterglow obscuration of all Swift-detected gamma-ray bursts (GRB), studying selection biases and advancing analysis methodology. While we find little redshift evolution, a clear correlation of host stellar mass and metal column density is revealed. A simple geometrical model explains the width and shape of the column density distribution and the trend with galaxy mass correlation. Our results implicate the host's galaxy-scale metal gas as the dominant obscurer. From a galaxy evolution perspective, our study places new independent constraints on the metal gas mass inside galaxies at z=0.5-4. We compare these with modern cosmological simulations (Illustris and EAGLE) and discuss implications for the obscuration of other sources inside high redshift galaxies, such as active galactic nuclei (AGN).

Jellyfish galaxies are objects exhibiting disturbed morphology, mostly in the form of tails of gas stripped
from the main body of the galaxy. We have undertaken the first systematical investigation of this
phenomenon in a sample of ~100 cluster galaxies selected because of they disturbed morphologies in B-
band images. MUSE data have been so far obtained for most of the sample. In this talk I will briefly present
the details of the survey and some of its preliminary results.

A rigorous assessment of parameter uncertainties is important across scientific disciplines. In this talk, I will introduce profile methods [1] for differential equation models. I will review established optimization-based methods for profile calculation and touch upon integration-based approaches [2] and novel hybrid schemes. The properties of profile likelihoods will be discussed and the relation to Bayesian methods for uncertainty analysis. Finally, I will show a few application examples in the field of systems biology [3].
References:
[1] Murphy & van der Vaart, J. Am. Stat. Assoc., 95(450): 449-485, 2000.
[2] Chen & Jennrich, J. Comput. Graphical Statist., 11(3):714-732, 2002.
[3] Hug et al., Math. Biosci., 246(2): 293-304, 2013.

Adopting the explosion properties derived by the first-principle
simulations, we perform a multigroup radiation hydrodynamics calculations of
the most massive electron capture supernovae and the lowest mass iron-core
collapse supernovae. The simulations use evolutionary preSN models of
different metallicity and derive the main characteristics of the explosions:
multicolor light curves from shock breakout to 56Co decay, photospheric
velocity and temperature, spectral energy distribution. The results of
simulations constrain what observational features we can expect from
low-mass supernovae and help to distinguish two types of their progenitors.

In this talk, I will present the first detection of laser-induced Raman (in addition to Rayleigh and Mie) scattering above Cerro Paranal with the MUSE integral field unit. This additional source of (non-elastic) scattering for the photons from the 4LGSF lasers (and the PARLA laser too) gives rise to a very specific set of emission lines that can contaminate certain observations at visible wavelengths. Beyond the physical description of the phenomena and the characterisation of its spectral signature, I will discuss some of the direct consequences of this effect for operations.

For a variety of precision measurements in flavour physics we need to understand strong interactions at an energy scale around 1 GeV. While the description of strong interactions is well understood at high energy where a perturbative expansion applies and at low energy where effective field theories such as Chiral Perturbation Theory for light quarks are very successful, its description in the intermediate energy region is much more problematic. In particular there is no comprehensive theory available to take resonances and their interactions systematically into account. In this lecture we show how this problem can be addressed to some extent using general properties of amplitudes relying on first principles such as unitarity, analyticity and crossing symmetry together with experimental data to successfully extrapolate the chiral perturbation results in a model-independent way in the 1 GeV region.

Emilie will present three lectures on her research. This is part 3.

Emilie is a Cluster guest. Local host: Martin Jung (Universe Cluster, TUM)

The National Optical Astronomy Observatory (NOAO) is the U.S. national
center for ground-based optical-infrared (OIR) astronomy. It is a
Federally Funded Research and Development Center (FFRDC) sponsored by
the National Science Foundation (NSF) and managed by the Association of
Universities for Research in Astronomy (AURA). The NOAO mission is to
enable discovery for the research community-at-large through open access
to world-class facilities, capabilities, services, and data products. At
NSF request, AURA is developing a plan to create the National Center for
OIR Astronomy (NCOA) by restructuring the Gemini Observatory, the Large
Synoptic Survey Telescope (LSST), and NOAO within a common
organizational framework. This talk will present NOAO and its current
activities, recent research highlights, and a forward look to NCOA.

Despite several years of studies, the chemical evolution history of the Large Magellanic Cloud (LMC), as well as its star formation history, is still poorly understood. Three main stellar populations have been identified in the LMC: (a) an old population, coeval to the Galactic Halo, (b) an intermediate-age population (1-3 Gyr) that is the dominant one, and (c) a young component related to the most recent bursts of star formation.  The studies available so far based on high-resolution spectroscopy provide mainly information about the chemical composition of the young/intermediate-age populations, while only a few studies on old LMC globular clusters provide information about the chemistry in the oldest stars of LMC.

In this talk I will present the first homogeneous metallicity scale of old LMC clusters obtained using high-resolution spectroscopy, discussing the differences in the main groups of elements between old LMC and Milky Way clusters.

Stars form in the densest parts of the interstellar medium. It is therefore this gas component that is the focus of research in order to explore the physics of star formation. The bathtub model proposes that star formation is not regulated by the amount of dense gas that one observes but rather by the rate of dense gas formation. It is the flux of gas through various phases that determines the star formation history of molecular clouds or galaxies and that one needs to consider in order to interpret observations of star formation regions.

One of the big challenges in astrophysics is the comparison of complex simulations to observations. As many codes do not directly generate observables (e.g. hydrodynamic simulations), the last step in the modelling process is often a radiative-transfer treatment. For this step, the community relies increasingly on Monte Carlo radiative transfer due to the ease of implementation and scalability with computing power. I show a Bayesian way to estimate the statistical uncertainty for radiative-transfer calculations in which both the number of photon packets and the packet luminosity vary. Our work is motivated by the TARDIS radiative-transfer supernova code developed at ESO and MPA by Wolfgang Kerzendorf et al. Speed is an issue, so I will develop various approximations to the exact expression that are computationally more expedient. Beyond TARDIS, the proposed method is applicable to a wide spectrum of Monte Carlo simulations including particle physics. In comparison to frequentist methods, it is particularly powerful in extracting information when the data are sparse but prior information is available.

Despite the successes of the standard Chandrasekhar-mass model to explain the observed properties of Type Ia supernovae (SNe Ia), they systematically fail to reproduce the faster light-curve evolution of low-luminosity events. Stephane will show that an ejecta below the Chandrasekhar mass is essential in reproducing the rapidly-declining light curves characteristic of SNe Ia at the faint end of the luminosity function. He will also demonstrate that such sub-Chandrasekhar-mass models present fundamental difficulties in reproducing the post-maximum evolution of brighter events. These results imply that a range of progenitor white dwarf masses is needed to reproduce the full range of observed SN Ia properties, and hence make a strong case for the existence of multiple progenitor channels for these events.

Stephane is a Cluster guest. Local host: Bruno Leibundgut (ESO)

The dwarf galaxies of the Local Group represent some of the
most discriminating tests of structure formation on small scales, and of
the Lambda-CDM cosmological model and its alternatives. Based on results
from the APOSTLE suite of cosmological hydrodynamic simulations of the
Local Group, I will discuss how the impact of baryonic physics affects the
relation between the observed galaxies and the underlying dark matter
structures. In particular, I will argue that many of the apparent
small-scale failures of Lambda-CDM can be resolved when processes
including supernova feedback and reionisation are taken into account,
resulting in a Local Group dwarf galaxy population that matches the
observed one. I will also discuss predictions for the dark matter
substructures that surround the Milky Way.

Nearest star-forming clusters represent the ideal regions for detailed studies of protoplanetary disks around pre-main sequence stars (PMS) down to late M-type stars/brown dwarfs. The key advantage of nearby associations is that they represent a group of coeval and cospatial stars, which will allow us to disentangle the influence of stellar and disk properties from age on the disk evolution. Veronica will present the first results of a survey of nearby associations carried out with APEX/LABOCA. In particular, she will concentrate on eta Chamaleontis, a nearby association at about 110 pc and an age of 4-8 Myr.  Veronica will also discuss future perspective for planet search with the upcoming instrumentations in nearby associations.

Veronica is a Cluster guest. Local host: Barbara Ercolano (LMU)

In the presentation, Matthias will aim to provide a brief overview of his recent scientific interests, namely precision low-energy QCD and determination of Standard Model parameters. As a prime example, hadronic decays of the tau lepton shall be discussed which are a promising source to determine the strong QCD coupling. A precise extraction is obstructed by the presumable divergence of perturbative series in Quantum Field Theory. Strategies to overcome this complication will be touched upon.

As usual we will offer fruits, snacks and soft drinks in the lounge area.

Matthias Jamin is a Cluster guest. Local host: Martin Beneke (TUM)

Stephane will present the numerical setup developed with his collaborators to predict the light curves and spectra of Type Ia supernovae (SNe Ia). These simulations are based on the 1D, non-LTE, time-dependent radiative transfer code CMFGEN. He will first consider the standard delayed-detonation explosion mechanism applied to Chandrasekhar-mass white dwarf stars. Then heI will show that their approach delivers an excellent agreement to observations, despite the 1D treatment, providing support to the viability of the standard Chandrasekhar-mass model. Stephane will discuss variations of this standard model involving a pulsation during the explosive phase, which could explain part of the observed diversity among SNe Ia.

Part 3 on 21st July, 12:00.

Stephane is a Cluster guest. Local host: Bruno Leibundgut (ESO)

For a variety of precision measurements in flavour physics we need to understand strong interactions at an energy scale around 1 GeV. While the description of strong interactions is well understood at high energy where a perturbative expansion applies and at low energy where effective field theories such as Chiral Perturbation Theory for light quarks are very successful, its description in the intermediate energy region is much more problematic. In particular there is no comprehensive theory available to take resonances and their interactions systematically into account. In this lecture we show how this problem can be addressed to some extent using general properties of amplitudes relying on first principles such as unitarity, analyticity and crossing symmetry together with experimental data to successfully extrapolate the chiral perturbation results in a model-independent way in the 1 GeV region.

Emilie will present three lectures on her research. This is part 2. Part 3 on 27th July, 11am.

Emilie is a Cluster guest. Local host: Martin Jung (Universe Cluster, TUM)

We present a tomographic method allowing to recover the velocity field at different optical depths in a stellar atmosphere. It is based on the computation of the contribution function to identify the depth of formation of spectral lines in order to construct numerical spectral masks probing different optical depths.
These masks are cross-correlated with observed spectra to extract information about the average shape of lines forming at a given optical depth and to derive the velocity field projected on the line of sight. We apply this method to time-series of spectra of the red supergiant star mu Cep and derive velocities
in different atmospheric layers. The main results will be discussed during the talk.

Currently, the Baade-Wesselink (BW) method is able to determine the
distances to individual classical Cepheids with an uncertainty
of 7-10 percent. In my talk I will describe our efforts to reduce
the systematic uncertainty of the method down to an expected 2-3%,
mainly by improving our knowledge about the p-factors of Cepheids
which are needed to transform the observed radial velocity curves
to the Cepheid pulsational velocity curves. The current uncertainty
on the p-factors dominates the systematic error on BW distances.

Type Ia supernovae (SNe Ia) are among the most energetic stellar explosions. With typical luminosities several billion times that of the Sun, SNe Ia are visible across a large fraction of the observable universe, and enabled the discovery of its accelerated expansion. These events are thought to result from the thermonuclear disruption of a carbon-oxygen white dwarf (WD) star as it approaches the Chandrasekhar-mass limit, through accretion from a binary companion. However, the nature of this companion and the mechanism by which the WD explodes are still debated. In this first talk Stephane will give an overview of the observed properties of SNe Ia and present the physical basis that led to the elaboration of a standard model for these events. He will also highlight several open questions that will need to be addressed with future observations and numerical simulations.

Part 2 on 20th July, 11am; part 3 on 21st July, 12:00.

Stephane is a Cluster guest. Local host: Bruno Leibundgut (ESO)

In this talk, I will present the results of a global Bayesian analysis of currently available neutrino data. This analysis will put data from neutrino oscillation experiments, neutrinoless double beta decay, and precision cosmology on an equal footing. I will use this setup to evaluate the discovery potential of future experiments. Furthermore, Bayes factors of the two possible neutrino mass ordering schemes (normal or inverted) will be derived for different prior choices. The latter will show that the indication for the normal mass ordering is still very mild and is mainly driven by oscillation experiments, while it does not strongly depend on realistic prior assumptions or on different combinations of cosmological data sets. Future experiments will be shown to have a significant discovery potential, depending on the absolute neutrino mass scale, the mass ordering scheme and the achievable background level of the experiments.

For a variety of precision measurements in flavour physics we need to understand strong interactions at an energy scale around 1 GeV. While the description of strong interactions is well understood at high energy where a perturbative expansion applies and at low energy where effective field theories such as Chiral Perturbation Theory for light quarks are very successful, its description in the intermediate energy region is much more problematic. In particular there is no comprehensive theory available to take resonances and their interactions systematically into account. In this lecture we show how this problem can be addressed to some extent using general properties of amplitudes relying on first principles such as unitarity, analyticity and crossing symmetry together with experimental data to successfully extrapolate the chiral perturbation results in a model-independent way in the 1 GeV region.

In the first lecture, we will review the so-called Omnès problem and build the pion vector form factor from data. This form factor is very important for many applications in flavour physics. We will discuss one of the most famous ones: the Standard Model prediction of the anomalous magnetic moment of the muon and in particular of the hadronic vacuum polarization.?

Emilie will present three lectures on her research. This is part 1. Part 2 on 19th July, 2:15pm and part 3 on 27th July, 11am.

Emilie is a Cluster guest. Local host: Martin Jung (Universe Cluster, TUM)

Recent theoretical studies of the Active Galactic Nuclei (AGN) have suggested that the "torus" surrounded by the nucleus is not static and uniform, but rather dynamic and inhomogeneous. The so-called "torus" should be a part of the multi-phase structure of the circumnuclear gas in the central sub-pc to 100 pc. We here investigate multi-wavelength emissions from the multi-phase interstellar medium around AGNs, based on our "radiation-driven fountain model”. As an example, we here discuss the nearest type-2 AGN: Circinus galaxy. Our model consistently explains the observed spectral energy distribution. Using a snapshot of our 3-D radiation-hydrodynamic simulations as an input, we conducted post-processed radiative transfer simulations for molecular/atomic and ionized gas in the central 16 pc. We compare the results with past and future observations by ALMA, VLTI, and X-ray satellites.

I will review recent work of my group on the currently largest systematic uncertainties
in the Cepheid-SN Ia method to determine the Hubble constant, the distance to the
adopted fiducial galaxy to calibrate absolute Cepheid period-luminosity relations,
and the effect of metallicity on Cepheid absolute magnitudes, particularly in the
near-infrared which is used in modern work on Ho. I will report on a distance determination
accurate to 1% to the LMC using late-type eclipsing binaries, and I will describe how
we are using Cepheids and eclipsing binaries in both Magellanic Clouds to achieve
the most accurate-ever measurement of the metallicity effect. I will also briefly describe
various ongoing projects which will lead to distances better than 1% to nearby binaries,
taking advantage of interferometry and an improved surface brightness-color relation
to predict very accurate stellar angular diameters. Finally, I will briefly mention how Gaia
parallaxes of Galactic Cepheids will lead to a dramatic improvement in the distances
obtained for Cepheid variables from the classical Baade-Wesselink method.

This talk is an introduction to the use of the Higgs boson to look for new physics. We will review the motivation for such analyses, the current LHC sensitivity to new phenomena and future prospects to discover new physics via the precise characterization of the Higgs properties. We will emphasize the use of Effective Field Theories to interpret the data.

Galaxy clusters are known to host a variety of diffuse and extended
radio sources, including tailed radio galaxies, radio bubbles filling
holes in the ICM distribution, diffuse giant radio sources revealing
the presence of relativistic electrons and magnetic fields in the
intra-cluster volume. It is currently matter of debate how the
non-thermal components that we observe at radio wavelengths affect the
evolutionary physics of galaxy clusters. In this talk, I will give an
overview of the expected impact of Square Kilometre Array (SKA)
observations on non-thermal cluster studies.

Size growth of dust grains is an important process in planet formation.
Recently, there are claims that the grain growth may have already happened
in class 0/I young stellar objects (YSOs), earlier than previously thought.
Such change in grain properties can affect the chemical composition
due to the change in the total surface area of grains.
We modeled the chemical compositions with a time-dependent gas-grain
chemical model. Our results show that sulfur species such as H2S, SO, and SO2
are most sensitive to the grain size. Future observations of those species
can be probes of grain growth in YSOs.

Time domain studies have revolutionized stellar astrophysics.  In particular, planet transit studies have proven to be extremely effective at detecting oscillations in luminous red giant stars.  When combined with spectroscopy, this permits extremely precise distances, masses and ages for populations that sample a significant fraction of the Milky Way galaxy.  I will review the current state of the art in asteroseismology, focusing on the joint APOGEE-Kepler (APOKASC) sample of almost 7,000 evolved stars with high resolution spectra, masses and ages.  I will also discuss using asteroseismic samples as age calibrators for high resolution surveys in general and will argue that the combination of asteroseismology and the Gaia mission will be extremely fruitful.  I'll close with some results on surprising populations in the Galaxy uncovered by seismic data and tests of stellar models and isochrones.

Being much brighter than red giant stars, globular clusters allow old stellar populations of galaxies to be studied spectroscopically to much greater distances. Using data from the WAGGS survey of massive star clusters in the Milky Way and its satellite galaxies and the SLUGGS survey of the globular cluster systems of massive early-type galaxies, I will talk about how we can measure the metallicities of globular clusters using the strength of the calcium triplet in integrated light. Using globular cluster metallicity distributions and the relationships between globular cluster colour and metallicity, I will present evidence that different galaxies with similar masses experienced different formation histories. I will compare these observations with the predictions of the E-MOSAICS simulations of the formation of globular cluster systems.

We present SMA CO 3-2 polarization observations and first ALMA CO 2-1 polarization observations toward NGC 1333 IRAS 4A. The CO Stokes I maps at an angular resolution of 0.3" reveal two bipolar outflows from the binary sources of NGC 1333 IRAS 4A. Close to the protostars, the CO polarization has a position angle approximately parallel to the magnetic field direction inferred from the dust polarizations. The CO polarization direction appears to vary smoothly from an hourglass field around the core to an arc-like morphology wrapping around the outflow, suggesting a helical structure of magnetic fields in the outflows. The helical magnetic field is consistent with the theoretical expectations for launching and collimating outflows from a magnetized rotating disk. The CO data reveal a PA of ∼30° deflection in the outflows. The variation in the CO polarization angle seems to correlate with the deflections. We speculate that the helical magnetic field contributes to ∼10° deflection of the outflows by means of Lorentz force.

Gravitational lensing has become a versatile tool to probe the mass distribution in the Universe. In this talk, I will start by following the chronological order to discuss the emergence of gravitational lensing as powerful modern cosmological tool that has nowadays branched in many sub-areas. Gravitational lensing in 2017 is a central piece of all ongoing and future wide field surveys (KiDS, DES, LSST, Euclid). Within this exciting new era, I will discuss the expected outcome of the current and future lensing studies, what can be learned from it and in combination with other wavelength surveys.

Extreme kinematics in the white dwarf population might imply old age
and halo membership for some of its members, although in a few cases
more unusual pathways are implicated. Spectral analyses of high-
proper motion white dwarfs deliver stellar parameters from which we
obtain a photometric distance and surface abundances from which
we collect some clues of past interaction and binary ejection.
I will summarize past and present work, including our own, aimed
at identifying possible halo white dwarfs that are used to estimate
the age the Milky Way. I will also describe a few extreme objects
with unusual hyper-velocity trajectories. Distance measurements
are the most challenging aspect of this work and, as we all often say,
Gaia should help sort this one out.

A significant fraction of white dwarfs have atmospheres that are polluted
by elements heavier than helium. The high gravities of white dwarfs imply
that these elements should sink below the atmosphere leaving either a pure
hydrogen or helium atmosphere. However the presence of these heavy
elements suggests that they are being accreted from the immediate
circumstellar environment of the white dwarf. In most cases this
circumstellar environment is composed of planetary or astroidal debris.
Our recent work on cool polluted white dwarfs has revealed that a
significant fraction also harbour a magnetic field. I will present our
work on cool polluted white dwarfs and discuss our current understanding
of the interaction between white dwarfs and their immediate environment. I
will also present possible scenarios for the origin of magnetic fields in
these stars.

Virtually all X-rays observed in deep fields originate close to growing supermassive black holes. X-rays indeed provide a clean and efficient selection of both unobscured and obscured AGN (active galactic nuclei). Recent work with deeper observations and improved analysis methodology allowed us to extend constraints on highly obscured, Compton-thick growth, thought to occur e.g. as a phase in mergers. We put constraints on the mass locked into black holes over cosmic time, an important constraint for cosmological simulations and our understanding of the co-evolution with galaxies. Further study of the obscurer of AGN reveals a complex behaviour with luminosity and redshift, which rules out entire sets of obscurer models. A new paradigm is proposed, the radiation-lifted torus model, in which the obscurer is Eddington-rate dependent and radiation pressure from the accretion process creates and displaces torus clouds. We place observational limits on the behaviour of this mechanism.

Massive elliptical galaxies exhibit the most massive black holes,
most extreme stellar initial mass functions, and most dramatic
size evolution over cosmic time.  Yet, their complex formation
histories remain obscure.  I will describe the ongoing MASSIVE
Survey, a volume-limited, multi-wavelength, spectroscopic and
photometric survey of the structure and dynamics of the 100 most
massive early-type galaxies within 100 Mpc.  A combination of
integral-field spectroscopy on sub-arcsecond and large scales
enables us to perform simultaneous dynamical modeling of the
supermassive black holes, stars, and dark matter.  I will also
highlight properties of other mass components -- cold, warm, and
hot gas -- from our multi-wavelength datasets.  I will discuss
the implications of these galaxies for ongoing black hole studies
such as the Event Horizon Telescope and the pulsar timing array
experiments searching for gravitational radiation.

Johannes will cover some methods for tasks astronomers face daily:
(1) Measuring a quantity of an astrophysical object (e.g. luminosity) under uncertainty 
(2) Combining multiple such uncertain objects for understanding the distribution of the population, sometimes under censorship. 
(3) Comparing complex models of physical effects.He will give a comparison of Markov Chain Monte Carlo and nested sampling algorithms, and review the state-of-the-art in nested sampling (MultiNest, PolyChord and beyond). New algorithms and easy-to-use implementations, including (Py)MultiNest and Stan, today make powerful tools available for analysing real problems with sufficient complexity.

In order to prove the existence of a critical end point (CEP) in the QCD phase diagram it is sufficient to demonstrate that at zero temperature $T=0$ a first order phase transition exists as a  function of the baryochemical potential $\mu$, since it is established knowledge from ab-initio lattice QCD simulations that at $\mu=0$ the transition on the temperature axis is a crossover.

We present the argument that the observation of a gap in the mass-radius relationship for compact stars which proves the existence of a so-called third family (aka "mass twins") will imply that the $T=0$ equation of state of  compact star matter exhibits a strong first order transition with a latent heat that satisfies
$\Delta\epsilon/\epsilon_c > 0.6$. Since such a strong first order transition under compact star conditions will remain first order when going to symmetric matter, the observation of a disconnected branch (third family) of compact stars in the mass-radius diagram proves the existence of a CEP in QCD. Modeling of such compact star twins is based on a QCD motivated NJL quark model with high order interactions together with the hadronic DD2-MEV model fulfilling nuclear observables.

Furthermore we show results of a Bayesian analysis (BA) using disjunct M-R constraints for extracting probability measures for cold, dense matter equations of state. In particular this study reveals that measuring radii of the neutron star twins has the potential to support the existence of a first order phase transition for compact star matter.

The mass loss from evolved stars plays a number of key roles in stellar and galactic evolution. As well as being the main source of dust and chemically-enriched material for the ISM, mass-loss is crucial to understanding the final fates of stars. At the high-mass end, mass-loss is the key parameter that determines when a given star will explode as a supernova, and what kind of supernova it will become. Meanwhile for low- and intermediate-mass stars, mass loss on the asymptotic giant branch (AGB) allows them to avoid this fate. I will present some recent developments in understanding the mass loss of AGB and red supergiant stars, along with some open challenges and new projects aiming to solve them.

Planetary systems form in circumstellar disks around young stars in the first few Myr of stellar evolution. The physical and chemical condtions of disks determine the properties and architecture of planetary systems at birth. Understanding these properties and how they evolve with time during the planet formation process is thus critical to understand the diversity of planetary systems. I will discuss the basic physical processes in disks and how to probe them observationally, focusing on some of the key basic techniques and physical processes.

The observational properties of a special class of stars (the so-called Blue Straggler stars – BSS) in Globular Clusters are discussed in the framework of using this stellar population as probe of the dynamical processes occurring in these high-density stellar systems. In particular, the shape of the BSS radial distribution and their level of central segregation have been found to be powerful tracers of the level of the dynamical evolution of the hosting cluster, thus allowing the definition of an empirical 'dynamical clock'.

We have completed large and complete ALMA surveys of the disks around young stellar objects in two star-forming regions, Lupus and sigma Orionis. The data reveal dust structure and gas masses and the samples are large enough to reveal correlations with stellar mass. By comparing the two regions, we follow the evolution of the dust and gas content from ~1 to ~4 Myr, the period when giant planets are expected to form.

Ultra-high energy, > 10^19 eV, cosmic rays (UHECRs) are now routinely detected by gigantic extensive air-shower detectors. Although the origin of these particles remains a mystery, their existence implies the existence of extreme, astrophysical sources that challenge models of high energy astrophysical acceleration within a few hundred megaparsecs. I will discuss the interpretation of the most recent measurements of extensive air-showers, focusing on studies of arrival directions, which have the potential to reveal the origin of ultra-high energy cosmic rays by association with astrophysical source positions. Information about the origin of UHECRs may also be offered by the UHE neutral particles that are expected to arrive in temporal coincidence with electromagnetic counterparts from the sources of UHECRs. In this context, I will present the activities of the Pierre Auger Observatory in real-time, multi-messenger transient searches, such as the ones currently being performed as part of the Astrophysical Multimessenger Observatory Network (AMON).

VESTIGE (A Virgo Environmental Survey Tracing Ionised Gas Emission) is a deep
blind Halpha narrow-band imaging survey of the Virgo cluster within its virial
radius (~ 104 deg.sq.). VESTIGE is a CFHT large program that will be carried
out with MegaCam in 2017-2019 (50 alloctaed nights). I will introduce the
survey describing its technical aspects and its scientific objectives, and
present the first results obtained after the analysis of some pilot observations
of a few representative Virgo cluster galaxies. The data obtained so far suggest
that the observation of the ionised gas emission at very low surface brightness
levels is to date one of the most powerful tools to study ongoing perturbations
in rich environments.

Massive protostars are born in parsec-scale molecular clumps that collapse and fragment, leading to the formation of a cluster of stellar objects. Gravity, turbulence, magnetic fields and feedback all play a role in determining the outcome of fragmentation of clouds and the formation of a protocluster.  In this talk, I will  present observations of massive molecular filaments and clumps at early evolutionary stages. I will discuss fragmentation, physical and chemical evolution of molecular cores and the implication of these findings to current ideas of massive star and cluster formation.

The discovery of the first extra-solar planet around a main-sequence
star in 1995 has changed the way we think about the Universe: our
solar system is not unique. Twenty years later, we know that planetary
systems are ubiquitous, orbit stars spanning a wide range in mass, and
form in an astonishing variety of architectures. Yet, one fascinating
aspect of planetary systems has received relatively little attention
so far: their ultimate fate.

Most planet hosts will eventually evolve into white dwarfs,
Earth-sized stellar embers, and the outer parts of their planetary
systems (in the solar system, Mars and beyond) can survive largely
intact for billions of years. Scattered and tidally disrupted
planetesimals are directly observed via transits in a single system,
discs of dusty debris are detected around a few dozen white
dwarfs. However, the most powerful probe for detecting evolved
planetary systems is metal pollution of the otherwise pristine H/He
atmospheres.

High-resolution optical and ultraviolet spectroscopy of these stars
provides a unique window into the bulk abundances of
exo-planetesimals, analogous to the way we use of meteorites to
determine the composition of the solar-system. The derived abundances
unambiguously demonstrate that the disrupted planetary bodies were
rocky in nature, with strong evidence for a significant water content
in some cases. These results provide critically important input into
the models of planet formation.

The cold phase of the interstellar medium has a central role in galaxy growth and evolution. In normal galaxies following the so-called “main sequence” of star-forming galaxies, the star formation rate is believed to be regulated uniquely by the amount of gas available, and more specifically by the mass of cold and dense molecular gas. Despite the enormous efforts to trace molecular gas in larger and larger samples of galaxies, at multiple scales and at multiple epochs, nearly all of our empirical knowledge of scaling relations linking molecular gas and galaxy properties is still based on observations of massive (e.g. M*>10^10 M_Sun), metal-rich and gas-rich spirals. There is therefore a strong motivation to test molecular gas scaling relations over a much broader dynamic range of galaxy properties. With this goal in mind, we have undertaken the “APEX low-redshift legacy survey of molecular gas (ALLSMOG)”, an ESO large programme to survey the CO(2-1) line emission in a sample of ~100 normal star forming galaxies in the local Universe, characterised by stellar masses (10^8.5<M*[M_Sun]<10^10), SFRs and gas-phase metallicities significantly lower than have been probed by previous CO observations. The reduced spectra have been recently released through the ESO Phase 3 platform. I will present our latest results based on the full ALLSMOG dataset.

Galaxy scaling relations have become quite an industry over the past 1-2 decades. For those who are "insiders" of this industry such scaling relations have become important tools, for those who are not - galaxy scaling relations can have a flavour of "mystery" or "magic".  I am myself a relative newcomer to this field, and in this introduction my aim is first to demystify the concept.  Once everybody feels comfortably convinced that no particular magic skills are required, the second aim is to show in a few examples how those relations can guide us towards an understanding of galaxy formation and evolution. If all goes well then I hope to be able to finish with a few examples of my favourite relations, and in particular show how they have evolved since the formation of the first galaxies in the early universe.

Dwarf galaxies are tracers of the fine-structure of the large-scale structure of the universe. In my talk I will present our recent dwarf galaxy surveys in the nearby Centaurus Group (Dark Energy Camera) and the M101 group complex (SDSS). Two planes of satellites around CenA were recently discovered, which provide a unique opportunity to test cosmological predictions beyond the Local Group. We find evidence that these satellite planes are corotating, posing a major challenge to Lamda+CDM. The implications of our findings for the standard model of cosmology and alternative models are critically discussed.

During the earliest protostellar stages of their formation, young stars generate fast collimated winds (or jets) which impact the parent molecular cloud through shock fronts. Protostellar shocks play a crucial role in the chemical evolution of star-forming clouds because they induce in the surrounding medium large variation of temperature and density, which can locally activate endothermic gas-phase reactions, ionization processes, and evaporation/erosion of dust grains and their icy mantles. The nature and properties of these shocks and jets are a source of major debate. The launching mechanism of the jet, the role of the magnetic field, or the shock properties (i.e. ionization fraction) are some of the key questions that remain to be answered. Powered by a low-mass Class 0 protostar, L1157 is the prototype of chemically rich outflows, and its strongest shock, L1157-B1, has been extensively studied from the infrared to millimeter wavelengths. In this talk, I’ll review the most relevant aspects of protostellar shocks, focusing on the main properties of the shock laboratory L1157-B1. I’ll also present the recent work we are conducting with several telescopes to obtain a compressive view of the bow-shock structure and chemistry.

Over the last 20 years we have understood the role that stellar mass has in
regulating the star formation history of galaxies, at least over the redshift
range 0 < z < 2. Here I present an analysis of the star formation histories of
some 75,000 galaxies in the redshift range 0.5 < z < 1.3 from the VIMOS Public
Extragalactic Redshift Survey (VIPERS), and primarily of the very high mass
objects observed in that survey,
that shows how other parameters play an equally important role in shaping the
overall evolution of galaxies, and their transition from the blue cloud to the
red sequence.

The SkyMapper Southern Survey is now approaching its first large data release, covering nearly all of the Southern hemisphere in six optical bands. This talk will cover all aspects of the project, from its history and operations to the science currently pursued. This includes searching for metal-poor stars in the Milky Way and bright quasars at high redshift as well as mapping temporal variations of star formation in nearby galaxies. SkyMapper also operates a transient survey to supply the local anchoring for SN Ia cosmology, and engages in optical follow-up of fast radio bursts and neutron star mergers. Public awareness for SkyMapper benefits from our Hunt for Planet Nine as broadcast by BBC Stargazing Live.

Many scientists take for granted that the model describing the Universe is the so-called Cosmological ‘concordance model’, whose major ‘ingredients’ are DARK (!) energy, DARK (!) matter and a small percentage of baryons. But is this popular model a result of the modern fundamentalism or of the globalisation? Are we fooling ourselves with modern ‘epicycles'?
I would like to show what observations are telling us and how ‘non-controversial’ physics is not able to explain the major features ‘seen’ in the Cosmic Microwave Background and in the Large Scale Structure of the Universe. Secondly I would like to introduce another discussion topic: physical laws are time-reversible, then, is time needed to describe a change?
Be aware: you will get neither a course in Cosmology nor in Quantum Gravity, only (I hope) some seeds for thoughts.

Deep extragalactic surveys at optical and infrared wavelengths have allowed us to estimate the stellar content and star-formation activity for millions of galaxies across cosmic time. By comparison, the gaseous phase which fuels galaxy growth has been studied for a far smaller number of galaxies. The last decade has, however, seen steady progress in this field as a consequence of new observational techniques and upgraded/new observatories like IRAM/NOEMA, ALMA and Herschel. I will review how, from rapidly growing samples of galaxies with measurements of the gas content, a consensus is beginning to emerge on the link between the amount of gas and other galaxy properties like star formation rate, stellar mass, and ultimately the position of galaxies in the cosmic dark-matter web. This improved understanding of galaxy scaling relations (in particular those observed by galaxies on the main sequence of star-forming galaxies) has allowed us to produce estimates of the overall baryon budget of the universe out to at least redshift z~3. I will also describe current efforts to establish the gas content of two less well understood populations of galaxies - starburst galaxies and passive/quenched galaxies - and discuss how a robust characterization of the gas in these systems is key to identifying how they have formed and evolved.

X-ray observations performed during the last few decades have provided a rich data base on accreting black holes and neutron stars in X-ray binaries. A strong coupling between the properties of the accretion flow and the presence of outflows, such as radio-jets and hot X-ray winds, has been found to be a fundamental property of black hole systems; a feature which might be shared by super-massive black holes in active galactic nuclei. I will present some novel results corresponding to the 2015 outburst of the prototypical black hole transient V404 Cyg (Munoz-Darias et al. 2016, Nature / 2017 MNRAS). During this event, arguably the most interesting of this kind in decades, we have discovered, using the GTC-10.4 m optical telescope, a sustained outer accretion disc wind, which is simultaneous to the radio jet. We find that this low temperature outflowing wind has a large covering factor, expands at 1% of the speed of light and triggers a nebular phase once accretion sharply drops and the ejecta become optically thin. I will discuss the implications of these results in the context of black hole accretion.

I will describe the shape of the bar and bulge of the inner Galaxy traced using red clump stars in VVV and UKIDSS as standard candles. These demonstrate that the Milky Way has a 5kpc bar whose central ~2kpc is the boxy/peanut bulge. This is significantly longer than previous estimates and thus limits the rotation speed of the bar since corotation must lie beyond 5kpc, making the bar longer and slower than previously thought.

This shape, together with a wealth of kinematic data on individual bulge stars, has been included in made-to-measure models of the inner Galaxy to produce dynamical models of the whole bar and bulge. The models have wide applicability and we have used them together with microlensing data to determinate that the IMF in inner Galaxy is indistinguishable from the local IMF despite the very different timescale and redshift of star formation.

The dynamical models place corotation at 6.1kpc, and they naturally reproduce the dynamics of the well known Hercules stream in the solar neighbourhood. A longer 5kpc bar and central bulge, rotating so that corotation lies at 6.1kpc, is therefore a consistent description that can be further tested with data from VVVX and GAIA DR2 next year.

Thanks to the revolutionary capabilities of the Hubble Space Telescope we have
made enormous progress in our exploration of galaxies across cosmic history
over the last two decades. Hubble allowed us to push the observational
frontier back to z~10-11, only ~400 Myr after the Big Bang. To date, we have
identified ~1000 likely galaxies at z>6, with up to 20 credible candidates at
z~9-11, one of which is even spectroscopically confirmed at z~11. These
unprecedented samples allow us to directly track the build-up of galaxies in
the heart of the cosmic reionization epoch, providing an increasingly more
complete picture. For instance, in combination with deep data from the Spitzer
Space Telescope we can now even probe the evolution of the stellar mass
density over 97% of cosmic history. In this talk I will provide an overview of
recent observational progress coming from very deep HST and Spitzer/IRAC
observations as well as from ground-based imaging and spectroscopy to study
the first generations of galaxies, and I will highlight the exciting
possibilities that are just ahead of us based on several major upcoming and
planned telescopes.

The formation of the central regions of disk galaxies that we call galactic bulges remains a debated topic in modern galaxy evolution.
In this respect, the bulge of the Milky Way offers a unique opportunity to investigate in detail the role that different processes (secular evolution, dynamical instabilities, hierarchical merging, dissipational collapse etc..) may have played in the Galaxy formation and evolution. Indeed, it is only in the bulge of the Milky Way that all stars can be individually resolved, allowing to correlate the global structural properties of the bulge with the characteristics of its stellar population, such as age, chemical content, and kinematics. However, this advantage comes with the need of covering a large area on sky (~500 sqdeg). In this respect, large observation programmes and surveys are now providing a global view of the bulge stellar population properties that can be used to constraint formation and evolution models.
I will review our current understanding of the three-dimensional structure, chemical composition, age and kinematics of the bulge as obtained from recent photometric (e.g. VVV/X, OGLE) and spectroscopic (e.g. ARGOS, GIBS, Gaia-ESO, APOGEE-N) surveys.

In this talk I will describe some early results from the Toronto/Yale/Harvard Dragonfly Telephoto Array (a.k.a. Dragonfly), a robotic imaging system optimized for the detection of extended ultra low surface brightness structures. Dragonfly's wide-field low surface brightness imaging performance makes it capable of directly imaging low surface brightness structures (such as galactic streams, galaxy stellar halos and faint dwarf galaxies) about 10x fainter than is possible with conventional telescopes. With its latest upgrade to 48 lenses, Dragonfly has become the world's largest all-refracting telescope. In this talk I'll describe how Dragonfly works and show some early results, mainly focusing on the properties of ultra-faint stellar halos, enormous stellar disks, and a new class of ghostlike ultra-diffuse galaxies, some of which are as big as the Milky Way but have about 1/100 of its stellar mass. I will also report on our plans to upgrade the array order to map out directly gaseous structures in the intergalactic medium, thereby tracing out the Cosmic Web, the large-scale network of dark matter filaments that is believed to connect galaxies to each other, and which is thought to be the largest coherent structure in the Universe.

I will present numerical models of the gas dynamics in the inner parsec of the Galactic centre. We follow the gas from its origin as stellar winds of around 30 observed young massive stars, until it is either captured by the central black hole, or leaves the region.  I will show how comparing the simulations with recent Chandra observations confirms the origin of the gas in stellar winds, and constrains the properties of Sgr A* outflows during the last few hundred years.

In order to study kinematics of galaxies, one uses spectroscopic observations, which provide us with the line-of-sight velocity component only. What about the two other velocity components? Can we get a handle on them for external galaxies, where proper motions are too small to detect? I will show that if a galaxy contains a feature with a mirror symmetry, like a bar, then from the observed line-of-sight velocity one can recover two velocity components in its disc, assuming that the vertical velocity is zero. What can we learn from having at hand these two velocity components? I will be glad to hear your ideas, but I will also present what I've got thus far: the estimate of dark matter contribution in central parts of galaxies, and the evaluation of pattern speed of the bar.

Due to their steep spectra, low-frequency observations of FR II radio galaxies potentially provide key insights in to the morphology, energetics and underlying physics of these powerful radio sources. However, limitations imposed by the previous generation of radio interferometers at metre wavelengths have meant that this region of parameter space remains largely unexplored.

In this talk, I present the latest results from the nearby-AGN KSP using LOFAR and the VLA at frequencies between 50 and 460 MHz to investigate the dynamics, energetics and particle acceleration in FR II radio galaxies. For the first time, this allows us to undertake well resolved, detailed studies of FR IIs at low frequencies and place tight constraints on the low-energy electron distribution, magnetic field strength, and total energy content of the lobes. I discuss the impact this has on our understanding of nearby FR II radio galaxies and how an improved knowledge of their spectral structure on small spatial scales advances our understanding of the mechanisms which drive these powerful radio sources.

Discovered in the 1960s, astrophysical masers (microwave lasers) occur in a range of environments,
such as comets, supernova remnants, star formation and the central parsecs of AGN. Their uses
include determination of physical conditions, they can be used to measure magnetic fields, obtain high accuracy masses and to make distance determinations. Masers are now being used to determine the Hubble constant, via the Water Megamaser Cosmology Project, and to study the spiral structure and kinematics of the Milky Way via the Bar and Spiral Structure Legacy (BeSSeL) Survey. In this lecture, I will cover different aspects of the maser phenomenon and their uses.

Weak gravitational lensing is a unique technique to map the distribution of dark matter in the universe. It is also a sensitive probe of large scale structures in the universe and cosmological parameters. I will first briefly describe the principles of weak lensing. I will then review the current observational status of this field, highlighting several new measurements especially from the ongoing Dark Energy Survey (DES). I will then discuss the status of tensions between cosmological probes and results for a new integrated approach to combine them.

I will argue that if black holes represent one the most fascinating implications of Einstein's theory of gravity, neutron stars in binary system are arguably its richest laboratory, where gravity blends with astrophysics and particle physics. I will discuss the rapid recent progress made in modelling these systems and show how the inspiral and merger of a binary system of neutron stars is more than a strong source of gravitational waves. Indeed, while the gravitational signal can provide tight constraints on the equation of state for matter at nuclear densities, the formation of a black-hole--torus system can explain much of the phenomenology of short gamma-ray bursts, while the the ejection of matter during the merger can shed light on the chemical enrichment of the universe.

If there is one thing in common throughout virtually all of modern astrophysics, that must be the importance of measuring the distance to celestial bodies. In fact, hardly any physics can be done without knowing the distance to the objects being studied. Cepheid stars are arguably the best stellar distance indicators. They were key in establishing the nature of the Universe at the beginning of last century and will play a major role into the foreseeable future, as we gain more insight in the physics that regulates them and in the systematics that affect their properties.

I will review the physical properties of Cepheid and their numerous applications, from probes of galactic structure and evolution to their role in investigating the nature of Cosmic Acceleration.

Observations of celestial objects are inherently a 2D mapping on the
sphere but astrophysical studies usually require the knowledge of 3D
positions. For most extragalactic sources, this estimation relies on
photometric redshifts which require strong assumptions and can lead to
catastrophic failures. In this talk I will show how it is possible to
use clustering measurements to infer redshifts for any type of
extragalactic sources. I will show how to turn this idea into a new
tool for redshift estimation and show how accurate it is. I will then
present applications of this "clustering-redshift" technique using
various datasets at UV, optical, IR and radio wavelengths, and will
show a number of surprises.

The field of proto-planetary discs is progressing enormously thanks to new instruments like ALMA and SPHERE. They have produced spectacular images of discs showing rings, gaps and other structures, which can be speculatively linked to the presence of planets in formation in the disc. I will advocate that theory plays a fundamental role for interpreting these observations. On one hand, if planets are responsible for the observed structures, I will show that the minimum planet mass observable is in the super-Earth/giant planetary core regime, thus enabling a large population of planets to be uncovered. I will discuss also how we can use these images to estimate the masses of the putative planets embedded in the disc. I will then comment on what we can learn from the spirals that have been observed in discs. On the other hand, these structures can also be due to other effects. I will show for example how the innermost gap in the closest proto-planetary disc to us, around the star Tw Hya, is best explained by photo-evaporation rather than by a planet.

Circumgalactic medium (CGM), the interface between the interstellar medium and the intergalactic medium (IGM), is a complicated site of entwined gas from the IGM accretion and galactic outflows. QSO absorption line systems are amongst the best places to study the physical properties of the CGM. MUSE observations of the host galaxy absorbers along with the QSO absorption line data provide a unique set of data to explore the gas flows in CGM. Here I present the results of our recent CGM studies using MUSE observations. In particular, I demonstrate the detailed analysis of a sightline where we find a bonafide candidate for the “cold-flow disk”.

In this talk I will review the state-of-the-art work on exoplanet characterization, mainly focusing on ground-based techniques. I will discuss what we do now, can do in the near future with instruments like CRIRES+, and later with the European Extremely Large Telescope. Detailed knowledge of the chemical composition and climate of Earth-like planets such as Proxima b and the seven TRAPPIST sisters are within reach.

Starburst galaxies at the zenith of the cosmic star-formation history are among the most   extreme star-forming engines in the universe. Their star formation rates, in the range  100–1000 solar mass per year, require large reservoirs of cold molecular gas to be delivered to their  compact cores in a sustained way over timescales of about 100 Myr, despite powerful feedback.  It is unclear how this is achieved. Because of its unique chemical and spectroscopic properties, CH⁺ unveils gas components invisible in CO emission: CH⁺ cannot form in cold  gas without supra-thermal energy input, so its presence highlights on-going dissipation of  mechanical energy or high UV-irradiation. The CH⁺ (J =1-0) line has a high critical density, so its detection in emission traces very dense gas, while absorption traces low-density gas.

We report ALMA detections of CH⁺ (J =1-0) lines in emission and absorption from  gravitationally lensed starburst galaxies  at redshifts between 2 and 4. The broad CH⁺ emission lines (linewidths > 1000 km/s) originate in a myriad of shocks, powered by massive stars and possibly active galactic nuclei. The CH⁺ absorption lines reveal highly turbulent reservoirs of diffuse gas, extending far out (> 10 kpc) the starburst cores of radii < 1kpc. We conclude that powerful galactic winds stir turbulence in the 10kpc-scale environment of the starburst cores, building up massive, multi-phase and gravitationally bound reservoirs that act as sustained mass and energy buffers to feed further star formation over the required timescales. In this picture, galactic feedback, mediated jointly by turbulence and gravity, extends the starburst phase instead of quenching it.

I will give a brief review of galaxy clusters and the CMB, and then introduce the thermal and kinetic Sunyaev-Zel’dovich (SZ) effects. I will compare this to X-ray emission from the intra-cluster medium and discuss some of the types of studies SZ observations have enabled alone and in combination with X-ray observations.

The MUSE Hubble Deep Field Survey is deepest spectroscopic survey ever performed over the entire Ultra Deep Field (UDF) area. It provides ~1700 spectroscopic redshifts, an order of magnitude more compared to the data that has been accumulated on the UDF over the past decade, up to AB 30 in magnitude and 6.7 in redshift. The depth and high quality of the data enables new and detailed studies of the physical properties of the galaxy population and their environments over a large redshift range. In this talk I will show in advance of publication a number of important results achieved by the survey on a diversity of topics: investigation of bias in photometric redshift, spatially resolved stellar kinematics at z~1, properties of CIII emitters, FeII emission in stellar forming galaxies, Lya luminosity function and its impact for reiniozation, Lya extreme EW objects undetected in UDF, Lya extended halos, evolution of the galaxy major merger rate with redshift, etc.

I will briefly introduce the ESA Gaia astrometric mission, its capabilities, science goals, and expected releases. I will then proceed to illustrate the potential and the limitations of Gaia data in crowded stellar regions, and in particular I will show some toy simulations of the Gaia science performances in globular-cluster-like fields.

ALMA has been producing stunning images and results for stars across

the mass and evolutionary ranges. In this talk, I will focus on some results

for Asymptotic Giant Branch Stars (AGB), Planetary Nebulae, Red

Supergiants (RSG) and Supernovae. An area of particular interest is the

shaping process by which AGB stars evolve to form often highly axisymmetric

Planetary Nebulae - what are the roles of binarity and magnetic fields? As

well as the mechanisms by which some of the stars are losing large amounts

of mass (10-7 to 10-4 Msun/yr) to the interstellar medium. Finally I will

discuss how ALMA long baseline and high frequency data are starting to

help answer some of the long-standing questions in stellar evolution.

Symbiotic stars (SySt) are long-period interacting binaries composed of a hot compact star --generally a white dwarf-- an evolved giant star, and a tangled network of gas and dust nebulae. Inspired by the fact that SySt are a promising  channel to supernovae Ia, it is clearly of prime relevance to determine their  population. We discovered a number of SySt in the Local Group galaxies, while using imaging techniques to search for planetary nebulae. Most of them showing a particular  emission line that is almost exclusive of symbiotic systems, the O VI Raman scattered line at 6825A. In this opportunity I will discuss the first results of our pilot project of an innovative technique to search for SySt, which --if proved to work--, will be far more efficient them those commonly used.

The fine structure line [CII] at 158 microns is one of the brightest emission lines in the spectra of galaxies. It is considered to be the dominant coolant for neutral atomic gas in the interstellar medium. Conveniently, [CII] is redshifted into the sub-millimeter and millimeter atmospheric windows for 4.5<z<9. At high redshift, [CII] is thus a unique tracer of galaxy formation and a promising probe of the epoch of reionization (z>6). However, so far, [CII] studies of very distant
galaxies have been limited, with detection of only a handful of galaxies. The full power of ALMA will revolutionize the field, detecting [CII] in individual galaxies in the heart of the reionization era. However, while ALMA will probably follow-up hundreds of high-redshift galaxies, its small field of view and narrow bandwidth will strongly limit its sensitivity/efficiency to conduct large unbiased spectral line surveys.

Rather than detecting [CII] in selected galaxies, we propose to map in 3-D the intensity due to the [CII] line emission, a technique known as Intensity Mapping. This technique measures signal fluctuations produced by the combined emission of the galaxy population on large regions of the sky in a wide frequency (thus redshift) band, and thus increases sensitivity to faint sources. I will discuss how [CII] intensity mapping measurements can offer a straightforward alternative for tracing the
large structure of galaxies at z>4.5. By measuring [CII] fluctuations, I will show how we can obtain unprecedented constraints on star formation and dust build-up at a key epoch in the Universe. I will also discuss how cross-correlation of the signals (e.g. [CII] and galaxy surveys), as well as the lower redshift (z<2) CO-line fluctuations, could be used to
further understand the physics of galaxy formation and reionization. Finally I will present the CONCERTO experiment, a [CII] spectrometer capable of covering few square degrees with a high sensitivity and proposed as a new intensity mapping experiment.

The chemical history of a galaxy is dominated by the nucleosynthesis occurring in many generations of stars. By deriving the abundance of different chemical elements in different types of stars, I will show with practical examples how one can decipher and constrain their chemical evolution.

Water is a key molecule in interstellar oxygen chemistry: it links grain-surface and gas-phase chemistry in molecular clouds, is a major gas coolant in star-forming regions, and plays a crucial role for life on Earth. Our understanding of where water is, and its abundance, particularly in star-forming regions, has increased manyfold with data from the Herschel Space Observatory. We are now approaching a complete picture of the water chemistry in star-forming regions, a picture which I will present.

In spite of our increased knowledge of the interstellar water chemistry, several open questions still remain regarding which physical components water traces near low-mass protostars. I will conclude the talk with an outlook of what can be done in the very near future with ALMA to address these questions, particularly with the new Band 5 receivers.

The 10-meter South Pole Telescope (SPT) is a millimeter wavelength telescope designed to conduct sensitive measurements of the cosmic microwave background (CMB) at arc-minute resolution. The SPT has successfully conducted a 2500 square degree survey to find clusters of galaxies from their distortion of the CMB, known as the Sunyaev-Zel'dovich (SZ) effect. The surface brightness of the SZ effect is redshift independent which allows an SZ survey to provide a nearly mass limited cluster sample out to the earliest epochs of cluster formation. The SPT has identified ~700 of cluster candidates. Of these, ~500 have been optically confirmed, with the majority being newly discovered clusters at z > 0.5. I will summarize the main results from the SPT cluster survey, including cosmological constraints from their measurement of the growth of structure.

Diffuse Interstellar Bands (DIBs) are non-stellar weak absorption features found in the spectra of stars viewed trough one or several clouds of interstellar medium (ISM). Almost one century after their discovery the precise nature of their carriers (the agent originating these features) remains a mystery. Still, DIBs present good correlations with the amount of neutral hydrogen along a given line of sight, the extinction and the interstellar Na I D and Ca H&K lines. Thus, irrespective of the actual nature of carriers, DIBs can be used to trace the structure of the ISM in the same way as others species, and they even offer certain advantages when used instead of (or in addition to) other tracers. In this lunch talk, I will present our on going work to use both optical and infrared DIBs to trace the ISM in our Galaxy.

I will present an introduction to the properties of interstellar dust in the Milky Way Galaxy, following the life cycle of dust from formation in the atmosphere and circumstellar shells surrounding evolved stars, to its alteration in the interstellar medium, to its metamorphosis into the seedlings of planets in the environment of newly formed stars. 

Supernova 1987A will turn 30 years old on the 23rd of February. It remains the first naked eye supernova in the last 4 centuries and has provided us with a wealth of data and insights into the evolution and death of massive stars. The talk will present an episodic trip through the early observations tying them into the understanding that in many cases was developed many years later. The current state of the supernova which is well on the way to becoming a supernova remnant will be discussed alongside the latest observations from Herschel, HST, VLT, ALMA and ATCA.

I will present recent results from the Spitzer Photometry and Accurate Rotation Curves (SPARC) database: the largest collection of mass models currently available for late-type galaxies (spirals and irregulars) at z=0. HI/Ha rotation curves provide the centripetal acceleration (gobs) at different radii, while Spitzer photometry at 3.6 um allows us to precisely estimate the baryonic gravitational field (gbar). We find that gobs tightly correlates with gbar over 4 dex. The correlation persists even when dark matter dominates. The observed scatter is remarkably small (0.13 dex) and largely driven by observational uncertainties. Early-type galaxies and dwarf spheroidals follow the same relation as late-type galaxies. The radial acceleration relation is tantamount to a "Kepler Law" for galactic systems: when the baryonic contribution is measured, the rotation curve follows, and vice versa.

Next generation probes of the galaxy distribution and the microwave background sky will be treasure troves of cosmological information. How do we exploit them to address the enduring puzzles of the physics of the beginning, gravitational clustering, and the accelerating expansion? Progress depends crucially on the ability to connect theory and data through statistical modelling. I will present recent methodological breakthroughs to overcome the challenges inherent in physics-based principled analysis of large cosmological data sets: 1) efficient full forward statistical models of large scale structure data; 2) new ways of parsimonious modelling of systematics while respecting the physical structure underlying the signal; 3) new iterative techniques for fast solution of inverse problems; and 4) the ability to develop robust and informative cosmological observables based on underdense environments, ie cosmic voids.

Introduction from history: sensitivity vs time. Scaling and conservation laws for instruments. Detectors in a nut shell. Constraints by the atmosphere: the good, the bad and the ugly ... A few prototypical instruments, admittedly with a bit of infrared bias ... Interferometry. New trends and technology. The grass is or is not greener elsewhere: instrumentation beyond ESO. How to calculate signal to noise ratios and certainly an E-ELT outlook.

The presentation will last for 90 minutes with a short break.

After more than 12 years the Rosetta spacecraft crash-landed on comet
Churyumov-Gerasimenko on September 30, 2016.  It has traveled billions of
kilometers, just to study a black, small (4 km diameter) boulder named
67P/Churyumov-Gerasimenko.  The results of this mission now seem to fully
justify the time and money spent in the last decades on this endeavor.
In the talk I will look back on the craziest mission ever flown by the
European Space Agency and point out its scientific highlights and its
technical challenges.  I will show how the results of this mission change
our understanding about the formation of the solar system, the Earth and
finally life itself.

I will begin by outlining how radio interferometry works, starting from the idea of coherence and explaining the differences from  optical interferometry.   The treatment will be mostly qualitative, avoiding mathematical complexity.  I will then present the basic Fourier relation of interferometry and ask the audience to play "guess the Fourier transform" for well-known objects and people. With luck, this will help to develop an intuitive feel for the idea. I will try to reinforce some important concepts like resolution, spatial scales and sampling and to demystify the "u-v plane".

The second part of the lecture will be on practical applications of radio and (sub-)mm interferometry: how do you pick an array and instrumental configuration to do your science?  I will give a quick tour of current and near-future arrays from LOFAR to ALMA, show how to pick the appropriate one and end with a quick overview of what to expect from data-reduction packages, pipelines and archives.

One of the biggest challenges to understanding how galaxies work is decoding
the role of the central supermassive black hole. Without feedback from the
black hole (?AGN feedback?), galaxy evolution models fail to produce realistic
massive galaxies and galaxy clusters. Somehow, accretion of matter onto the
central black hole of a massive galaxy is tuned so that it regulates radiative
cooling and the condensation of gas in a volume of space many orders of
magnitude larger than the zone of gravitational influence around a black hole.
The effects of these black holes is most easily seen in the observations of
the most massive galaxies in the universe, the central galaxies of galaxy
clusters. Strong observational evidence now indicates the activity of the AGN
is closely coupled to the thermodynamic state of the circumgalactic medium,
where most of a galaxy?s baryons reside. I will discuss how this relationship
could arise and how a feedback mechanism that maintains the circumgalactic
medium in a marginally unstable state can regulate star formation within
galaxies.

It now seems that Cosmic Rays (CRs) can destroy the CO molecule in star forming galaxies very effectively, potentially rendering large H2 gas distributions (CO-line)-invisible, especially in the so-called Main Sequence (MS) galaxies. I will discuss the chemistry behind it and a way out in re-acquiring the CO-invisible H2 gas distributions in galaxies. Finally the effects of CRs in resetting the initial conditions for star formation in galaxies will be discussed, along observations that may have started revealing this already.

Gaia mission is underway conducting its nominal 5-year survey of the sky.
The first Gaia data release (Gaia DR1) took place 14 September 2016.
Exploitation is at full speed with preprints appearing on a regular basis.
At the moment two and half years of routine phase has been completed and
preparations for the second data release (Gaia DR2) are in full swing. In
the presentation the status of the mission is outlined with a short
explanation of some operational aspects and their impact on the mission. A
selection of early results from Gaia DR1 is presented. With a few examples
extracted from the early mission data the further potential of Gaia
is demonstrated. An outline of the contents for Gaia DR2 is provided.

I will present results based on sub-arcsecond resolution observations of massive Young Stellar Objects (YSOs) in the Magellanic Clouds. I will start by briefly describing the background and context for this study. The observations, carried out in the NIR with SINFONI at the VLT, reveal a wide variety of spatially extended emission line morphologies, indicative of outflows and compact HII regions. Through a comparison of massive YSOs in the Magellanic Clouds and a Galactic sample, evidence of significantly enhanced accretion rates towards the YSOs in the Magellanic Clouds is detected. Whilst the underlying mechanism of this enhancement is uncertain, there appears to be a convincing correlation between metallicity and accretion rates in massive YSOs.

​Through analysis of the ancillary optical spectra in the context of the SINFONI data the massive YSOs in the SMC appear to reside in a porous ISM, allowing a large mean-free-path for energetic photons.​ These results have been published by Ward et al. (2016, 2017).

In the last century our observations of the Universe have revealed deep mysteries that remain challenging enigma for our understanding of fundamental physics. What is Dark Matter that embraces the visible structures in the Cosmos? What is the putative Dark Energy that accelerates the expansion of the Universe?

In my presentation, I will in the first part, present new high precision measurements on the Dark Matter mapping of massive galaxy clusters using the Hubble Frontier Fields observations. These and future similar observations may ultimately help us uncover physical properties of the Dark Matter.

In the second part, I will present extended-BOSS the current Sloan spectroscopic surveys as well as other projects that will help us constrain in particular the nature of Dark Energy and the mass of neutrinos.

Finally, I will present recent technology developments of high-density fiber positioner systems for the coming and future generation of wide field spectroscopic surveys that are planned to significantly improve in precision cosmological measurements.

Evolved hot, luminous stars are known to drive strong mass loss
(10^{^-10} - 10-5 Msol /yr) from their surfaces through UV-scattering
forces. These same forces also efficiently ablate material o ff the
surface of circumstellar disks, both in the late phases of massive
star formation, and during the main sequence phase of Classical Oe and
Be stars. By using a fully three-dimensional UV-scattering
prescription (Castor, Abbott, and Klein 1975; Cranmer and Owocki
1995), we here quantify the role of radiative ablation in removing
material from such disks, focusing on results for Classical Oe and Be
stars (Kee et al. 2016).

Condensate clouds have significant role in shaping atmospheric structure and spectra of exoplanets and brown dwarfs. Specifically, the appearance of red color among brown dwarfs and exoplanets like HR 8799bcde, 2M1207b are suggested as the evidence of thick dusty cloud in atmosphere. However, the link between cloud structure and physical parameters like surface gravity remains poorly understood. Under Hubble Space Telescope Cloud Atlas Program (P.I: Daniel Apai), we use rotational modulations to measure cloud structure variation at different atmospheric levels and compare rotational amplitudes of various surface gravity and spectral types objects. In this talk, I will present one of the largest rotational modulation of an unusually red L-dwarf,  WISEP J0047, and discuss it's implication to our current understanding of dusty cloud structure.