Join us for the traditional presentation of this year Nobel Prize laureates.

ALMACAL is an extensive (sub-)millimetre survey taking advantage of the high sensitivity reached in the fields of ALMA calibrator observations. We analyse all calibration data taken by ALMA since Cycle 1 (more than 2000 hours of observing time!) to conduct a number of surveys, including multi-band and multi-epoch surveys of dusty star-forming galaxies, a blind CO survey to study the evolution of the cold gas content of the Universe, redshifted molecular absorption line surveys, and line intensity mapping. In addition, the data offer a unique opportunity to investigate the spectral behaviour and variability of a large sample of bright extragalactic sources: the calibrators themselves. Here, we give a summary of the ALMACAL survey strategy and the science potential, addressing a large range of problems in extragalactic astronomy.

Have you ever wondered how major companies including Apple, Google, Airbnb, Nike or SAP come up with the ideas for their products? These companies use flavours of the user-centric design method called Design Thinking. This method is a step-by-step approach to innovation unleashing the creative potential of a group of people. It can be used to design products or systems or for trying to find solutions to any complex problem in life. In this informal discussion we look the background, the ingredients and the steps of Design Thinking and we can discuss together whether or not the approach could be used within ESO. 

Exoplanet population studies indicate that small rocky planets should be common around very low-mass stars and brown dwarfs (‘ultra-cool dwarfs’, SpT>M7). However, the M8 star TRAPPIST-1 is currently the only ultra-cool dwarf known to harbour planets. I will describe and present preliminary results from our on-going Spitzer search for transiting planets around equator-on ultra-cool dwarfs.

LP 40-365 is a runaway star, whose atmosphere is dominated by oxygen, neon, and magnesium. Additionally, it contains super-solar traces of iron-peak elements. Its composition and remarkable kinematics suggest this star formed via the failed disruption of a near-Chandrasekhar mass white dwarf in a peculiar thermonuclear supernova that unbound the binary progenitor. LP 40-365 is the prototype of a new class of objects, which appear as low-mass (0.2-0.3 Msun), inflated white dwarfs of 0.2-0.6 solar radii. The known members of this class have a homogeneous chemical composition, physical and kinematic properties. Future theoretical and observational work will help to better constrain the characteristics of their binary progenitors, explosion mechanisms, and nucleosynthetic yields.

We investigate the stellar kinematics of galactic bulge and disk components using 830 galaxies with various morphological types from the Sydney-AAO Multi-object Integral-field spectroscopy (SAMI) Galaxy Survey. The rotation velocity and velocity dispersion of bulge and disk components have been simultaneously estimated using the penalized pixel fitting (pPXF) method with photometrically defined weights of two components. We introduce a new subroutine of pPXF to avoid physically meaningless solutions. We present the Tully-Fisher and Faber-Jackson relations showing that the stellar mass scales the velocity and velocity dispersion of both bulge and disk components for all galaxy types. Also, we first introduce a tight correlation between the stellar mass and the velocity dispersion in disk components. We show that bulge and disk components are kinematically distinct: (1) two components show scaling relations with similar slopes, but with different intercepts; (2) the spin parameter Lambda_R indicates bulges are pressure-dominated system, and disks are supported by rotation; (3) bulge and disk components present low and high values in intrinsic ellipticity. We reproduce the rotation and dispersion of galaxies using the kinematics and weights of two components. The agreement between the reproduced and observed kinematics suggests the combination of two distinct components draw the kinematics of galaxies.

One of the most important quantities needed to explain how planets form is the mass of their precursors, protoplanetary disks. Determining the total disk mass – which is dominated by the gaseous component – has proven to be very difficult. On one hand dust-based disk masses depend on the assumptions on the dust properties and on the gas/dust ratio, and on the other hand CO-based gas masses are affected by the uncertainty on the chemical processes. Other molecules, such has small hydrocarbons, can be used to put some constraints on the chemistry. Hydrogen deuteride (HD), on the other hand, is a promising alternative and has already proved to be a game changer thanks to the few detections by the Herschel Space Telescope. SPICA is now the only near-future instrument which may allow us to expand the sample of HD detections and mass measurement in a statistically relevant sample of disks. After summarizing the results from different ALMA disk surveys and their implications, I will present alternative observational strategies which may help us to solve the disk mass puzzle.

This year the Nobel Prize in Physics was awarded and shared between James Peebles "for theoretical discoveries in physical cosmology”, and Michel Mayor and Didier Queloz "for the discovery of an exoplanet orbiting a solar-type star.” During this informal discussion we will give a general overview of the state of the respective research fields at the time these Nobel laureates performed their work. Then we will highlight some of the technical and observational challenges that had to be overcome, and point out how and where they have contributed and transformed their fields (and our view of the Universe).

A prominent jet-driven outflow of CO(2-1) molecular gas is found along the kinematic minor axis of the Seyfert 2 galaxy ESO 420-G13, at a distance of 340-600 pc from the nucleus. The wind morphology resembles a characteristic funnel shape, formed by a highly collimated filamentary emission at the base, likely tracing the jet propagation through a tenuous medium, until a bifurcation point at 440 pc where the jet hits a dense molecular core and shatters, dispersing the molecular gas into several clumps and filaments within the expansion cone. We also trace the jet in ionised gas within the inner ~340 pc using the [NeII]12.8µm line emission, where the molecular gas follows a circular rotation pattern. The wind outflow carries a mass of ~8 x 10^6 Msun at an average wind projected speed of ~160 km/s, which implies a mass outflow rate of ~14 Msun/yr. Based on the structure of the outflow and the budget of energy and momentum, we discard radiation pressure from the active nucleus, star formation, and supernovae as possible launching mechanisms. ESO 420-G13 is the second case after NGC 1377 where the presence of a previously unknown jet is revealed due to its interaction with the interstellar medium, suggesting that unknown jets in feeble radio nuclei might be more common than expected. Two possible jet-cloud configurations are discussed to explain the presence of an outflow at such distance from the AGN. The outflowing gas will likely not escape, thus a delay in the star formation rather than quenching is expected from this interaction, while the feedback effect would be confined within the central few hundred parsecs of the galaxy.

The Fornax cluster provides a uniquely compact laboratory in which to  study the detailed history of early-type galaxies and the role played by the environment in driving their evolution and their transformation from late-type galaxies. I would like to present a new "picture" of the Fornax cluster that emerged like a puzzle in the latest years. It is based on dedicated studies using deep imaging from the Fornax Deep Survey (FDS),  and the high-quality integral-field data obtained with MUSE@VLT from the Fornax3D project. Both surveys map the Fornax cluster out to its virial radius. The analysis pointed out the complex structure of the cluster, suggesting that it is not completely relaxed inside the virial radius. The bulk of the gravitational interactions between galaxies happens in the W-NW core region of the cluster, where most of the bright early-type galaxies are located and where the intra-cluster baryons (diffuse light and globular clusters) are found. We suggest that the W-NW sub-clump of galaxies results from an infalling group onto the cluster, which has modified the structure of the galaxy outskirts (making asymmetric stellar halos) and has produced the intra-cluster baryons (ICL and GCs), concentrated in this region of the cluster. These studies could be considered as a benchmark for (simulations of) the assembly and evolution of galaxies in a cluster environment.

Being a scientist, especially in astronomy, should be a joyful experience. Yet we can sometimes find ourselves overwhelmed with the pressure, stress and uncertainty the can come with the job. Furthermore we can encounter people and situations that may make you feel miserable and question is it all worth it. We will explore why we can lose the joy of science and discuss what we can do as a group and - importantly for ourselves - to try and navigate the challenges of the career whilst maintaining the joy and enthusiasm that it should entail.

The estimated number of black holes in the Galaxy from simple stellar evolution considerations is about 100 million, a large fraction of which are expected to besingle. Yet, not a single isolated black hole has been detected to date -- all the few dozen black hole mass determinations so far have been in binaries. In addition, there is a nagging inconsistency between the measured masses of black holes in our Galaxy, masses expected from theoretical calculations, and the LIGO measurements. Mass determinations of a few isolated, stellar-mass black holes will provide important clues in our understanding of black holes. Astrometric microlensing is the only available technique capable of detecting isolated black holes and measuring their masses. I will discuss the technique, and our HST programs aimed at the first detections of stellar-mass black holes through this technique.

Thanks to ALMA our understanding of gas and dust in galaxies over cosmic time and their connection to other galaxy properties has improved dramatically. I will discuss a number of the results from the ALMA large program ASPECS, a spectroscopic survey at 1 and 3 millimeter with ALMA of the Hubble Ultra Deep Field. This survey marks the deepest observations of a 4.2 arcmin^2 contiguous area on the sky and pushes our understanding of gas and dust in high-redshift galaxies even further. The aims of this survey include measuring the cosmic evolution of the molecular gas density and the gas properties of galaxies; the deepest measurement of the 1 millimeter continuum number counts and it’s connection to the underlying galaxy population; improving our understanding of dust obscuration at high redshift; and constraining the [CII] luminosity (function) of high-redshift galaxies. I will present the main survey design and after that focus on some of the individual results of the survey, guided by the interest of the audience.

P/2016 G1 is an "active asteroid", i.e. a main belt asteroid that suddenly displayed a cloud of dust. We observed its evolution for a few month, and could re-constitute the details of what happened to it using a few millions of test particles, a little detective work, and hydrodynamics simulations of nuclear weapon explosions.

I will provide for those that couldn’t attend a succinct and very biased account on the ESO workshop on Artificial Intelligence in Astronomy that took place July 22-26 and attracted more than 130 participants.

Observations in the infrared and sub-mm using the Herschel and ALMA suggest that stars form in high mass density filaments in giant molecular clouds while embedded star clusters and high mass stars reside at the intersection of filaments, hubs and ridges. What imprint does the star formation in filaments leave in young stellar populations just emerging from their natal molecular clouds? In this informal discussion we show that GAIA-DR2 data allow us to answer this question.

Conceiving gravity as a force that emerges from an unknown microscopic structure, is a new paradigm. Recent progress in the description of gravity as an entropic force enables predictions/"post"-dictions for galaxy dynamics. When disks can be used to determine galaxy masses, these predictions are confirmed with an impressive precision, the well-known MONDIan phenomenology (Milgrom/Bekenstein).

However, deviations as "dark matter poor" or "dark matter rich" galaxies are found for elliptical galaxies. These are still obstacles for a satisfactory and more complete understanding of gravity. 

We will briefly report on the recent workshop “The VLT in 2030” which was held in Garching two weeks ago: https://eso.org/sci/meetings/2019/VLT2030.html. After the introduction, we will discuss what you may have learned at the workshop, if you attended, or answer questions you may have, if you did not attend the workshop.

How and when the stellar mass content of galaxies is assembled is still one of the main questions of galaxy evolution studies. The existence of a very tight relation between the galaxy star formation rate (SFR) and the stellar mass (M*) suggests that most galaxies form their stars at a level mainly dictated by their stellar masses and regulated by secular processes. Such relation, called the Main Sequence (MS) of star forming galaxies, is in place from redshift ~0 up to ~4 and it is considered one of the most useful tools in astrophysics to study the evolution of the  star formation activity in galaxies.

More than 500 papers in the literature explored in the past 15 years, with a variety of star formation rate indicators and techniques, how the slope and scatter of the relation evolve across cosmic time. I will show that, when all of the selection effects are taken into account, all these results point to a rather consistent  picture, with surprising consequences for the cosmic star formation history of the Universe.

While ancient scientist often have patrons to fund their work, peer review of proposals for the allocation of resources is a foundation of modern science. A very common method is that proposals are evaluated by a small panel of experts (due to logistics and funding limitations) nominated by the grant-giving institutions. The expert panel process introduces several issues - most notably: 1) biases introduced in the selection of the panel. 2) experts have to read a very large number of proposals given a very limited time. Distributed Peer Review promises to alleviate several of the described problems. In this process, the task of reviewing is distributed among the proposers. Each proposer is given a limited number of proposals to review and rank. The process promises – among others – making grant allocation more transparent, making the voices of junior scientists heard, and lowering the load of review tasks on the senior academics. We present the result of an experiment running a distributed peer review process for allocation of telescope time at the European Southern Observatory. We have introduced several enhancements to the ‘classic’ distributed peer review, including using natural language processing and machine learning algorithms in identifying research expertise, and the addition of a step to provide an evaluation of the reviews encouraging the reviewers to provide useful feedback. The results of our experiment show a very high success rate in predicting the expertise of reviewers given proposals. The general experience has been overwhelmingly praised by the participating community (using an anonymous feedback mechanism). I will give an overview of our experiment in this talk.

In a reprise of the famous 1919 solar-eclipse experiment that confirmed general relativity, the nearby white dwarf Stein 2051B passed very close to a 19th magnitude background star in 2014. As it passed in front, Stein 2051B caused a deflection of the background star's image by ~2 milliarcsec, which we observed with HST at 8 different epochs. This allowed us to determine the mass of Stein 2051B using this technique of astrometric microlensing for the first time outside the solar system. Our measured mass of Stein 2051B, the sixth- nearest white dwarf, provides confirmation of the physics of degenerate matter, and lends support for white-dwarf evolutionary theory. The recent Gaia data allow accurate prediction of many such upcoming events which can be used to determine accurate masses of single stars.

The presence of Raman-scattered laser guide-star photons above the VLT was first reported in 2017. Here, I will present the outcome of a series of dedicated follow-up observations of the 4LGSF up-link laser beams acquired with MUSE and ESPRESSO.

From a series of MUSE observations acquired over a 27 month period, we find evidence that dust on the primary and secondary mirror of the telescope is responsible for up to (60+-5)% of the laser light contaminating MUSE WFM-AO observations. As such, laser lines provide an ideal, non-invasive means to monitor the scatter properties of the UT4 telescope mirrors on a sub-nightly basis. This could allow, for example, to assess (with a single metric) the qualitative impact of operating with high-particle counts, and the ability of CO2 cleanings to mitigate long-term consequences.

In February 2018, we used ESPRESSO to acquire a high-resolution (R~140'000) spectra of one 4LGSF up-link laser beam. The richness of the Raman spectra associated with the laser beam, revealed in a spectacular fashion by ESPRESSO, provides an ideal and unique means to characterize the as-built accuracy of the ESPRESSO spectrograph.

Altogether, these observations demonstrate that laser guide-star systems at astronomical observatories ought to not only be thought of as mere sub-components of complex adaptive optics systems, but also as powerful monitoring tools and accurate spectral calibration sources: both for existing and upcoming facilities.

Since its discovery by Henize (1956), numerous observations have been made of the supergiant B[e] star LHA 115-S 18 (S18). The optical spectrum of the star is characterised by strong emission in the Balmer series and prominent He I lines as well as a wealth of forbidden and permitted low excitation metallic lines. Following the behaviour observed in other sgB[e] stars, the high excitation lines are broader than the metallic lines and exhibit pronounced variability in profile and strength – the Balmer lines evolve from (asymmetric) single peaked to P Cygni profiles and vary in strength by a factor of ∼3 (Zickgraf et al. 1989; Nota et al. 1996). The most dramatic variability, however, is seen in the He II 4686 Å line, which has been observed to transition from absence to being comparable in strength to H Beta, with such changes occurring over short timescales (of the order of months; Shore et al. 1987). Clark et al.(2013) used archival spectroscopic and photometric data to show that whilst S18 trivially satisfies the eponymous classification criteria of LBVs, it does not conform to their typical behaviour as outlined by Humphreys & Davidson (1994): The photometric variability occurs at unprecedented rapidity and these spectral and photometric changes appear completely uncorrelated, in stark contrast to the behaviour of normal LBVs. S18 has been detected at X-ray wavelengths both by Chandra (in 2002) and XMM-Newton in (2003) with L_X~10^33 erg/s, however, in a deeper XMM observations in 2006, the source was undetected, suggesting a factor 10 variability at X-ray wavelengths.

Since mid 2014, S18 has been monitored spectroscopically, with the Southern African Large Telescope (SALT), and photometrically as part of the OGLE project then the by the Remote Observatory in the Atacama desert (ROAD). In July 2018 a VLT XSHOOTER spectrum revealed that the source was transitioning into its ''hot'' state (in which He II 4686 A is at maximum), a state never monitored and a transition that has never before been observed. We were granted a further 10 hours of observations with XShooter and 14 hours with SALT. The target is also being monitored at X-ray wavelengths as part of the Swift monitoring of the High Mass X-ray Binary population of the SMC. Far from finally revealing the nature of this enigmatic target, however, this dataset, and specifically the XSHOOTER data, has revealed yet more unexpected and unexplained behaviour including a strong UV excess at wavelengths < 360 nm, similar to those reported in Young Stellar Objects (Manara et al. 2016). In this discussion session, I aim to summarise all the data from this "outburst" and, with the help of the participants, finally find an answer to the question "What is LHA 115-S 18?"

Directly detection of radiation from extrasolar planets is the premier method for determining exoplanet atmospheric composition. Direct detection of young giant planets can also probe formation processes near the snow line, which is thought to be where giant planet formation is most likely. Existing instruments have largely failed at detecting a significant population of giant planets. I will outline why they have failed, and what is needed to significantly change this and open up a new subfield of observational exoplanet research. I’ll outline the potential for a METIS and a high contrast VLTI instrument (Hi-5/VIKiNG), and describe why eventually space interferometry is needed. I’ll finish by outlining a pathway for space interferometry, and describe why it isn’t has hard as you might think.

In the last 6 months, the VLTI/GRAVITY and Event Horizon Telescope experiments have ushered in a new era of spatially resolved studies of event horizon scales around massive black holes. I will discuss the experiments, their first results, and the implications for understanding the role of magnetic fields in black hole accretion and jet launching and for future tests of strong field general relativity.

The mass of the Milky Way is one of its most fundamental properties, important for understanding the MW itself, the past and future of the Local Group of galaxies, and where the MW sits in a cosmological context. Yet mass estimates in the literature are significantly scattered and many estimates differ by more than their uncertainties. Mass estimates rely on accurately measuring total velocities of objects within the MW, but historically we have only been able to measure one component of motion, leaving two components unknown. However, this has changed thanks to recent proper motion measurements from HST and Gaia. I will talk about why knowing the mass of the MW is so important, how we can measure it, why there has been such disagreement in the past, and how recent HST and Gaia measurements are finally bringing better agreement.

Numerous models of galaxy evolution expect that AGN should have a negative feedback effect on star formation in their host galaxy, by injecting energy into the ISM in the form of powerful outflows. In this informal discussion, I will focus on observational evidence of multi-phase outflows in optical spectra of nearby AGN. In particular, I will show which are the best tracers of ionised and atomic outflows among emission and absorption lines commonly observed in optical spectra. Then, I will talk about general outflow properties and their connection with AGN activity. In the last part, I will discuss gas mass outflow rate and related energetics, generally used to estimate the feedback impact on galaxy evolution.

Brown dwarfs populate the lower end of the IMF, and bridge the mass space between low-mass stars and planets. Due to their low mass, there is a strong debate about their formation mechanism(s). In order to confirm or discard those, we need to detect, and characterize, the different stages of brown dwarf evolution, which is no easy task. Ww have followed a systematic approach to the subject in our collaboration, from which we can extract some general lessons, and advice. Nonetheless, interesting and puzzling questions and challenges still remain and it is worth to keep them in mind. 

Magnitude, color, spectrum, and coordinates of light sources are the main parameters measured in most of the astronomical observations. However, the incoming light might show some degree of polarization. Polarimetric measurements allow to unveil important properties of the source and of the light path, otherwise hidden in common observations. We will discuss some aspects of polarization of light and its measurement with the Focal Reducer/low dispersion Spectrograph, FORS2, mounted on the VLT. In 2019 ESO is celebrating the 20th Anniversary of first light for FORS2.

A recently proposed SN Ia channel is via the so-called sub-Chandrasekhar double-detonation scenario. In this scenario a white dwarf (WD) is orbited by a core Helium(He)-burning compact hot subdwarf star (sdB/sdO) in an ultra-compact orbit (Porb < 80 min). Due to the emission of gravitational waves, the binary is predicted to shrink until the hot subdwarf star fills its Roche lobe and starts mass transfer. He-rich material is then transferred to the C/O-WD companion which will lead to the accumulation of a He-layer on top of the WD. After accreting a small amount He-burning is predicted to be ignited in this shell. This in turn triggers the ignition of carbon in the core even if the WD-mass is significantly lower than the Chandrasekhar limit. However, the number of known systems is still limited. The Zwicky Transient Facility (ZTF) is a new time-domain survey with a 47 sqd. survey camera. I am scientific lead of a high-cadence survey in the Galactic Plane covering the full inner Plane visible from the northern hemisphere as part of ZTF. The goal of this survey is to uncover the population of short period variable stars in the Galaxy. In this talk I will present the discovery of several ultracompact white dwarf binaries with hot subdwarf companions as well as our strategy to find more systems using ZTF.

The evolution of galaxies is largely shaped by the interplay between inflows, star formation and feedback processes. Heavy elements are key tracers of this cycle of baryons in and out of galaxies. In this talk I will use observations of nearby galaxies to explore the link between metal enrichment and their history of star formation. While this approach is typically employed in systems where individual stars can be resolved, I will discuss the challenges involved in measuring gas and stellar metallicities from integrated light. I will then explore what can be learnt from applying chemical evolution models to the overall galaxy population, as observed in large spectroscopic surveys.

The unconscious brain processes are an important part of everyday life, but what effect do they have on our work, on the choices we make in the professions and our interplay with colleagues? I will present a few findings and discuss possible measures to adopt in order to make the workplace a fairer environment.

Strong gravitational lenses with measured time delays between the multiple images can be used to determine the Hubble-Lemaître constant (H_0) that sets the expansion rate of the Universe. Measuring H_0 is crucial for inferring properties of dark energy, spatial curvature of the Universe and neutrino physics.  I will describe techniques for measuring H_0 from lensing with a realistic account of systematic uncertainties, and show the latest results from the H0LiCOW program.  I will show the bright prospects of gravitational lens time delays as an independent and competitive cosmological probe.

As astronomy advances, the biggest gains are often found by combining different kinds of data in a single analysis, e.g. combinations of photometry, spectroscopy, imaging etc. However, such combinations pose a number of statistical challenges that inhibit simple analyses and require new tools to solve them. A key challenge is self-consistently combining data with radically different statistical and systematic uncertainties. I will highlight some recent advances in forward-modelling astronomical data that dramatically improve this situation, before presenting a new tool to fit general combinations of observations.

As a sequel to the Q&A session on the ELT telescope, the Project Scientists of the ELT instruments will provide an opportunity to ask question on those facilities.

A short introduction to METIS, HARMONI, MICADO+MAORY, MOSAIC and HIRES instruments will be given. Thereafter, the floor will be open for questions.

Proper motions are crucial to fully understand the internal dynamics of globular clusters. To that end, the High-Resolution Space Telescope Proper Motion (HSTPROMO) collaboration has constructed large, high-quality proper-motion catalogues for 22 GCs in the Milky Way. For most clusters, these catalogues provide the most detailed kinematical data to date, with tremendous potential for improving our understanding of the dynamics and structure of individual clusters. Moreover, the size and diversity of the cluster sample, spanning a broad range of cluster properties (including environment and dynamical state), allows new studies of the GC populations as a whole. I will discuss some of our exciting recent results including: the first 2D kinematical maps for a large sample of GCs; the first directly-measured radial anisotropy profiles for a large sample of GCs; the first dynamical distance and mass-to-light ratio estimates for a large sample of GCs; and the first dynamically-determined masses for hundreds of blue-straggler stars across a large GC sample.