Seminars and Colloquia at ESO Garching and on the campus

The MHONGOOSE Large Survey Project is obtaining ultra-deep 21-cm neutral hydrogen (HI) observations with the MeerKAT radio telescope to map the distribution and kinematics of the low column-density gas in and around 30 nearby star-forming spiral and dwarf galaxies. These deepest resolved HI observations of nearby galaxies to date serve to put additional constraints on the role of accretion of cold gas in the replenishing of these galaxies' gas reservoirs. Observations for the survey have just completed and MHONGOOSE is routinely reaching its target HI column density sensitivity of a few times 10^17 atoms cm^-2, two orders of magnitude lower than the typical values found in galaxy HI disks. Our full-depth data show that the outskirts of our galaxies are complex and dynamic environments, with many potential accretion and interaction features visible in HI that only now become visible due to the excellent column density sensitivity.  We detect a significant number of uncatalogued low-mass dwarf galaxies, which enable "Local Group science" in environments at tens of Mpc distance. A first comparison of the MHONGOOSE observations with simulated HI maps from recent cosmological simulations show a marked difference in kinematics and morphology, indicating that cold gas accretion is likely happening in a more gentle way. The sensitive MHONGOOSE observations point the way to a better understanding of the role of gas accretion in galaxy evolution in the nearby universe and identifies opportunities for new HI surveys with the upcoming SKA-MID telescope.

Type Ia and other peculiar supernovae (SNe) are thought to originate from the thermonuclear explosions of white dwarfs (WDs). Some of the proposed channels involve the ejection of a partly exploded WD (e.g. Iax SN remnant) or the companion of an exploding WD at extremely high velocities (>400 km s^-1). Characterization of such hyper-runaway/hypervelocity (HVS) WDs might therefore shed light on the physics and origins of SNe. Here we analyse the Gaia DR3 data to search for HVS WDs candidates and peculiar sub-main-sequence (sub-MS) objects. We retrieve the previously identified HVSs and find 46 new HVS candidates. Among these we identify two new unbound WDs and two new unbound sub-MS candidates. The remaining stars are hyper-runaway WDs and hyper-runaway sub-MS stars. The numbers and properties of the HVS WD and sub-MS candidates suggest that extreme velocity ejections (>1000 km s^-1) can accompany at most a small fraction of type Ia SNe, disfavouring a significant contribution of the D6-scenario to the origin of Ia SNe. The rate of HVS ejections following the hybrid WD reverse-detonation channel could be consistent with the identified HVSs. The numbers of lower-velocity HVS WDs could be consistent with type Iax SNe origin and/or contribution from dynamical encounters. We also searched for HVS WDs related to known SN remnants but identified only one such candidate ( https://ui.adsabs.harvard.edu/abs/2023MNRAS.518.6223I/abstract).

Our understanding of planet and star formation is mainly based on already formed planets around (sub-)solar-like stars. In this talk, I aim to broaden our perspective by focusing on protoplanetary disks around more massive stars, leveraging the special properties of their stellar interiors. In particular, convective sub-photospheric regions disappear during the pre-main-sequence evolution of stars with masses roughly between 1.5 and 4 Msun. In turn, the absence of convection influences the mixing of stellar material, the strength of the magnetic field, and consequently, the way disk material is accreted by the central stars. I will summarize our recent findings on the metallicity and accretion properties of intermediate-mass young stars in relation to disk structures, the potential presence of giant planets, and the size of their innermost orbits. I will conclude by presenting our ongoing efforts to reliably determine disk-to-star accretion rates of the most massive young stars with fully radiative envelopes.

Numerous protoplanetary disks exhibit shadows in scattered light observations. These shadows are typically cast by misaligned inner disks and are associated with observable structures in the outer disk such as bright arcs and spirals. Investigating the dynamics of the shadowed outer disk is therefore essential in understanding the formation and evolution of these structures. We carry out two-dimensional radiation hydrodynamics simulations that include radiative diffusion and dust–gas dynamics to study the formation of substructure in shadowed disks. We find that spiral arms are launched at shadow edges, permeating the entire disk. The local dissipation of these spirals results in an angular momentum flux, opening multiple gaps and leading to a series of concentric, regularly-spaced rings. We find that ring formation is favored in weakly turbulent disks where dust growth is taking place. These conditions are met for typical class-II disks, in which bright rings should form well within a fraction of their lifetime (~0.1–0.2 Myr). For hotter disks gap opening is more efficient, such that the gap edges quickly collapse into vortices that can appear as bright arcs in continuum emission before decaying into rings or merging into massive, long-lived structures. Synthetic observations show that these structures should be observable in scattered light and millimeter continuum emission, providing a new way to probe the presence of substructure in protoplanetary disks. Our results suggest that the formation of rings and gaps is a common process in shadowed disks, and can explain the rich radial substructure observed in several protoplanetary disks.

Neutrinos are fascinating particles heralding the dawn of multi-messenger astronomy. Neutrinos affect the stellar dynamics, drive the formation of new elements, and carry signatures of the yet mysterious physics governing the most energetic transients in our universe. Recent developments on the role of neutrinos in cosmic sources will be reviewed together with the most exciting multi-messenger detection prospects.

Dusty star forming galaxies (DSFGs) are increasingly understood to be the primary contributors to the cosmic star formation rate density at least out to z~4 and sites of proto-cluster environments. We modeled the far-infrared and millimeter spectral energy distributions (SEDs) of 71 DSFGs selected at millimeter wavelengths by the Atacama Cosmology Telescope (ACT) with a lower flux density limit than previous catalogs of galaxies selected at the same wavelength. All candidates were cross-identified with detections in the Herschel SPIRE maps, and decomposed into possible multiple counterparts using a probabilistic cataloging (PCAT) algorithm. We obtained targeted observations of nineteen of our sources using the Submillimeter Array (SMA) telescope to acquire high resolution imaging and flux extraction to compare to the lower-resolution, single dish fluxes as well as assess the validity of the case for multiple components. In this talk, I will discuss the physical properties of the galaxies if they are treated as single sources with flux densities indicated by the single dish observations, but in this we exercise caution. ACT's lower flux limit, the PCAT decomposition, and the higher-resolution SMA observations all suggest that many of these DSFGs are likely to be unlensed and possibly multiples. I will then highlight the need for more efficient mapping of DSFG environments out to high redshift, and what the future may hold for unveiling the growth of structure through the (sub-)mm lens.

Galactic cosmic rays and stellar energetic particles are relativistic particles that reach exoplanets. Depending on their energy, they can penetrate exoplanetary atmospheres, similar to what occurs on Earth. The main properties, relevant for these energetic particles, that vary for exoplanetary systems in comparison to the solar system are the stellar winds properties, the exoplanet atmosphere composition and the stellar energetic particle spectrum. The properties of stellar energetic particles for stars other than the Sun remain elusive.

For exoplanetary atmospheres, one of the most important effects due to Galactic cosmic rays and stellar energetic particles is that they ionise the atmosphere. This ionisation leads to exotic chemistry depending on the atmospheric composition. Energetic particles can also drive the formation of prebiotic molecules, the building blocks of life in exoplanet atmospheres. These effects are also relevant for the early Earth atmosphere.

I will discuss our simulation results which show the ionising impact of energetic particles in exoplanetary atmospheres and the early Earth atmosphere. I will show how the stellar wind can affect the energetic particle flux reaching an exoplanet. Finally, I will discuss how JWST could detect the signature of energetic particle-induced chemistry in an exoplanet atmosphere. Such a detection could be used to constrain the energetic particle flux impacting on the exoplanet atmosphere.

I will review the magnetospheric accretion model as applied to T Tauri stars and the properties of protoplanetary disks that can be inferred from its application, including gas temperature, surface density, inner edge of dust disk,  molecular dissociation/ionization, and disk Ionization structure. I will discuss recent findings on the highly inhomogeneous nature of the magnetosphere. I will finish discussing the application of the magnetospheric models to find the abundances of refractory materials reaching the innermost disk, and what they can reveal about the history of the disk.

Selecting AGN candidates from photometric data, with the goal of spectroscopic follow-up, is a challenging yet essential task for spectroscopic surveys. In this study, we use a Random Forest classifier on photometric data from the Zwicky Transient Facility (ZTF) to identify AGN candidates. To target low-stellar-mass galaxies, we crossmatch these candidates with the NASA-Sloan Atlas (NSA) catalog, focusing on galaxies with stellar masses 𝑀∗<2×1010𝑀⊙. Using archival optical spectra from SDSS, we confirm the AGN nature of 357 (86%) out of 415 candidates through the presence of broad emission lines. Additionally, using data from eROSITA data release 1, we find that 67% of the candidates in the eROSITA-DE sky have an X-ray counterpart.

The discovery of over 5,000 exoplanets has revolutionized our ability to address fundamental questions about planetary habitability and evolution: Are there Earth-like worlds in the Universe? Can they support life? My research accelerates the discovery and characterization of habitable planets by combining cutting-edge observations with advanced models to characterize the atmospheres and surfaces of rocky and low-temperature exoplanets, trace their evolutionary pathways, and search for signs of liquid-water oceans.

In this talk, I will discuss recent breakthroughs in the study of rocky exoplanets, including the first detection of a magma-ocean atmosphere on 55 Cancri e and the discovery of a volcanic, SO₂-rich atmosphere on L 98-59 b using JWST. These findings provide unprecedented insights into the interplay between geological processes and atmospheric evolution, establishing the emerging field of exoplanet geology. I will also present ongoing efforts to identify liquid-water conditions on temperate sub-Neptunes, illustrating how innovative models, such as our next-generation planetary atmosphere framework, EPACRIS, enable us to predict key atmospheric signatures and interpret groundbreaking JWST observations. 

Finally, I will discuss the path forward for characterizing Earth-like planets and highlight how today’s exoplanet studies drive scientific and technological priorities of future exploration.

I will describe an extended, ongoing observational effort aimed at discovering and studying the properties of a large sample of dual and strongly lensed QSOs at sub-arcsec separations. With these data, we will be able to address numerous scientific questions, including testing several previously untested predictions of galaxy/SMBH evolution models, developing more accurate predictions of massive BH merger rates and LISA GW event rates, and studying dark matter distribution in the central kpc of lensing galaxies. We select candidates using Gaia and Euclid data and follow up on targets with various space- and ground-based telescopes, including an ESO large program with VLT/MUSE, to obtain spatially resolved spectroscopy. This has produced, for the first time, a substantial sample of confirmed dual AGN beyond the local universe, and the most compact quadruply lensed QSO ever discovered.

The origin of supermassive black holes (SMBH) in galaxy centers remains uncertain. They could have emerged either from massive "seeds" (100k-1M MSun) in the early Universe or from smaller (100 MSun) remnants of massive Pop-III stars, which would leave behind numerous intermediate-mass black holes (IMBHs, 100-100k MSun). The largest published sample of bona-fide IMBH-powered AGN contains only 14 objects confirmed in X-ray. I will present X-ray confirmation of 24 new optically selected IMBH candidates from a sample of 305 objects taken from Chilingarian+2018. Additionally, using the same method, we investigated 100+ AGN powered by "light-weight" SMBHs (<1e6 Msun). For the selection and confirmation of this sample, we used a multiwavelength approach utilizing both archives and our follow-up observations: optical spectra from SDSS for initial sample selection, different epoch spectra from observations with VLT, Keck, Magellan, and SALT, high-resolution imaging from HST and Magellan, and, ultimately, X-ray confirmation of sources with eROSITA, Chandra, XMM-Newton, and SWIFT. In this talk, I will present the statistical properties of our sample of X-ray confirmed IMBHs and its implications for BH growth scenarios.

Adaptive optics (AO), originally used for correcting the effect of turbulence on images in ground-based telescopes, has now been used for more than 25 years to image targets at cellular- and subcellular-scale for applications in the biological sciences. Using AO to correct the static and dynamic optical aberrations of the living human eye, has provided revolutionary tools to scientists and clinicians to study the retinal structure and function, revealing details without the need for histology. AO ocular imaging is non-invasive and easily tolerated by patients . Applied to high-resolution imaging of the living human eye with Scanning Laser Ophthalmoscopes (SLO) and Optical Coherence Tomography (OCT), this talk will cover the most relevant aspects to consider when designing a closed-loop AO imaging system for ocular imaging.

The last decade of observations of protoplanetary discs have shown a wealth of substructure including rings, gaps and spiral arms. Perhaps most intriguingly these observations also revealed the importance of the 3D structure of discs, where some discs are observed to have orientations that change as a function of radius or may also be broken. These so called 'warped discs' have challenged our understanding of disc evolution, and recent work has shown that these discs form a significant fraction of the disc population. In this talk I will discuss the connection between warped discs and the onset of planet formation, a major open question in planetary science.

Observational surveys of the distribution of matter in the universe are becoming ever more precise and continue to be extended to smaller scales. This necessitates accounting for the fact that baryons do not precisely trace the dark matter. The redistribution of baryons by galactic winds, which is the major bottleneck in our understanding of  galaxy evolution, therefore requires a convergence between models of large-scale structure and cosmology. I will present results from the FLAMINGO suite of large-volume cosmological, hydrodynamical simulations. The fiducial simulations have been calibrated using machine learning to reproduce the low-z galaxy mass function and cluster gas fractions, but the suite also includes systematic variations in the galaxy formation model and cosmology. The simulations provide insight into the importance of baryonic effects for cosmology using large-scale structure and galaxy clusters.

The Gaia mission has recently completed its last scientific observations. This is a good time to reflect on why this is a great mission, with one of the worst data access policy. I will provide a biased view on some of the revolutionary results it led to and provide a brief overview of what is still planned for the young and patient people in the audience.

Gamma-ray emission produced by interactions of cosmic rays with interstellar matter and radiation fields is a probe of non-thermal particles in galaxies. After decades of technological advancements in gamma-ray astronomy, several key results have significantly advanced our understanding of cosmic ray physics. However, there are still a few critical questions that remain unresolved. This review offers an overview of the current state of the field, while also exploring how next-generation gamma-ray facilities can further advance research in this area. Specifically, we will highlight the capabilities of the Cherenkov Telescope Array Observatory (CTAO). CTAO will be the first proposal-driven observatory in this energy range, providing science-ready data to the global research community.

Quantum Computing (QC) is a paradigm with disruptive potential in many areas of computational sciences and large projected impact in research, industry and society. In my talk I will provide a general overview of the main concepts of QC and how it can be integrated into the High-Performance Computing ecosystem as a suitable tool for astronomy and astrophysics. Although application areas in these disciplines are in the first stages of exploration, a few promising directions will be highlighted. Finally, the access paths to QC systems for the local research community will be described.

Galaxies don’t just form stars—they continuously exchange gas with their surroundings. This circumgalactic medium (CGM) is a turbulent, magnetized mix of gas shaping how galaxies evolve. Observations reveal a multiphase CGM, but capturing this complexity in simulations is a major challenge due to small lengthscales involved. 

In this talk, I will explore:

- Why small-small effects in multiphase astrophysical gas are important?

- How turbulence & magnetic field shape CGM structure?

- How a new subgrid model can bring these small-scale effects to large-scale cosmological simulations?

By improving how we model the CGM, we can better interpret observational data and refine our understanding of galaxy evolution. Let's talk about how we can make that happen.

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The Informal Discussion is in-person only, and held in the ESO library.

At around 10:30, we will continue in the discussion at science coffee.

The Herschel observations unveiled the complex organisation of the interstellar medium in networks of parsec-scale filaments over the past decade. Despite their variety of scales throughout the interstellar medium, the analysis of these same observations revealed filaments in nearby low-mass clouds to have a characteristic width of ~0.1 pc. The origin of this characteristic width and its impact on star formation, however, has been a matter of intense discussions in the past years. Even more with the identification of small-scale filamentary structures harboured inside the Herschel filaments. These networks of fibers have been recognised describing the gas structures in star-forming regions at sub-parsec scales, thus critically challenging the existence of a typical width for filaments.I am going to present our study of the dense gas organisation prior to the formation of stars in a sample of 7 star-forming regions within Orion. This EMERGE Early ALMA Survey includes OMC-1/-2/-3/-4 South, LDN 1641N, NGC 2023, and the Flame Nebula, all surveyed at high spatial resolution (4.5'' or ~2000 au) in N2H+ (1−0) using ALMA+IRAM-30m observations. I will present the star-forming gas spatial distribution, its column density variations, its thermal structure, and its internal motions across the 152 fibers identified in our survey.

Over the past 15 years, the Atacama Large Millimeter/submillimeter Array (ALMA) in the Chilean desert has revolutionized our understanding of planetary formation. ALMA has not only provided the expected large samples and high-resolution images of planet-forming material, but it has also led to groundbreaking discoveries that challenge existing theories. One of the most striking revelations is that planets form much faster than previously thought. In this talk, I will explore the key concepts and scales involved in the process of building planets from micrometer sized cosmic dust. I will discuss how theory and observations help us reimagine how planetary systems, both similar and very different from our own, are formed.

In order to understand galaxy growth evolution, it is critical to constrain the evolution of its building block: gas. Mostly comprised by Hydrogen in its neutral (HI) and molecular (H2) phases, the latter is the one mostly directly associated to star-formation, while the neutral phase is considered the long-term gas reservoir. Both phases are difficult to detect directly either due to high excitation temperatures or low transition probability. As a result, while HI direct observations have been limited to the local Universe and extended to high redshifts when seen in absorption, H2 has been traced indirectly via tracers, either Carbon Monoxide (CO) rotational transitions, atomic Carbon fine structure transitions, or dust emission at (sub-)mm wavelengths. However, the latter best tracers the combined content of HI and H2 masses. In this work (Messias et al. 2024), we make use of an empirical relation between dust emission at millimeter wavelengths and total gas mass in the inter-stellar medium (M_HI plus M_H2) in order to retrieve the HI content in galaxies. We assemble an heterogeneous sample of 335 galaxies at 0.01<z<6.4 detected in both mm-continuum and carbon monoxide (CO) low-J transitions. More specifically, a blindly selected sub-sample had a special focus given its suitability to retrieve HI cosmological content when the Universe was ~2-6 Gyr old (1<z<3). Overall, we find no significant evolution with redshift of the M_HI/M_H2 ratio, which is about 1–3 (depending on the relation used to estimate M_HI). This also shows that M_H2-based gas depletion times are underestimated overall by a factor of 2–4. Compared to local Universe HI mass functions, we find that at least the number density of galaxies with M_HI>1E10.5 Msun significantly decreased since 8–12 Gyr ago. The specific sample used for this analysis is associated to 20-50% of the total cosmic HI content as estimated via Damped Lyman-alpha Absorbers. In IR luminous galaxies, HI mass content decreases between z~2.5 and z~1.5, while H2 seems to be constant or increase. Finally, the results obtained in this work allow us to report source detection predictions for SKA1 surveys and what is the most suitable strategy to detect HI at cosmic noon.

Recent simulations of AGN feedback have found that the impact on the host galaxy’s gas changes during an AGN phase. Using radio-AGN that harbour bright jets, we can trace young and evolved AGN phases, and even multiple AGN phases in a single source. New and ongoing large area surveys like LoTSS (with LOFAR) and VLASS (with VLA), now make it possible to build large samples of radio-AGN and characterise their spectra. Combining this with optical spectroscopic surveys like SDSS and MaNGA can provide interesting insights into the link between the radio-AGN life-cycle and feedback. In this context, I will present our results on radio-AGN feedback on ionised gas, where we find evidence for [OIII] kinematics to be most disturbed during the young AGN phase (on average), which lasts for ~0.1-1 Myr after the AGN is triggered. We find that the feedback on [OIII] is intrinsically linked to the evolutionary stage of an AGN phase, irrespective of source luminosities, black hole and stellar masses, and accretion rates. I will then discuss the relative contribution of jets and radiation in low luminosity radio-AGN, combining LoTSS and MaNGA. Finally, I will briefly present our ongoing work on jet-ISM interaction in a high-redshift (z~3.5) radio-AGN.

Since 2017, the Atacama Large (sub-)Millimeter Array (ALMA) has been participating in regular Very Long Baseline Interferometry (VLBI) observations both with the Event Horizon Telescope (EHT, at 0.8–1mm) and the Global Millimeter VLBI Array (GMVA, at 3–7mm). The advent of ALMA in this type of observations has resulted in a revolution in our capability to image and study the environment around super-massive black holes (SMBHs) down to event horizon scales, and thus the way we infer their properties. In this presentation, I will justify why we need these observations of SMBHs, and go through the results obtained towards M87* and SgrA* thus far, but also other sources that, unfortunately, did not receive equal attention (eg, CenA, 3C279, OJ287, NRAO530). I will then finalize with the near-future capabilities of VLBI observations with ALMA, but also the capability of ALMA-standalone phased-array observations for time-domain studies with timing precisions down to ~100microsec.

The boundaries of relativistic black hole jets—at the interface between the jet and the disk wind—lie at the core of our recent understanding of jet-powered phenomena. They harbor intense velocity and magnetic shears, which provide the free energy needed to power a number of observational signatures. We demonstrate that magnetic reconnection—a process by which opposite field lines annihilate, releasing their energy to the plasma—ultimately governs dissipation of the available free energy at jet boundaries. Reconnection resulting from the nonlinear evolution of Kelvin-Helmholtz type vortices can naturally explain the limb-brightened radio emission of AGN jets, such as M87. Also, inverse Compton scattering within the chain of magnetic islands / flux ropes self-consistently created by reconnection at the jet boundaries can power the mysterious hard X-ray “coronal” emission of X-ray binaries. We will also argue that reconnection-driven hadronic acceleration in the coronal regions of NGC 1068 may be the source of the TeV neutrinos recently detected by IceCube.

Quasar microlensing is both an invaluable astrophysical tool and a complicating factor in measurements like the Hubble constant from lensed quasars. Previous studies have focused on the Einstein ring crossing time for a single microlens, but the combined gravitational effects of the lens galaxy (mean field) and other microlenses (fluctuating field) significantly influence microlensing properties. In this talk, I will present our recent work extending a statistical analysis of microlensing to all currently known lensed quasars with available data, incorporating realistic optical depths, updated quasar sizes, and galaxy peculiar velocities. By generating microlensing magnification maps using the fast multipole method and inverse polygon mapping, we find a mean source crossing time, and an Einstein radius crossing time.  Moreover, I will highlight how interactions among microlenses and the overall gravitational shear play crucial roles, with approximately 13% of quasar images experiencing high-magnification events. These results have important implications for quasar microlensing and future observational campaigns.

Fellowship selection processes in academia are designed to reward scientific excellence, yet research suggests that bias—especially unconscious bias—can subtly influence evaluation outcomes, often disadvantaging underrepresented groups. In this informal discussion, we will first explore the impact of bias on selection processes, with a particular focus on hidden, unconscious biases that shape decision-making without evaluators even realizing it We will then examine how prestigious fellowship programs, including Marie Skłodowska-Curie Actions (MSCA), the European Research Council (ERC), and other major astronomy and astrophysics fellowships, attempt to mitigate these biases. Using insights from peer-reviewed studies and official funding reports, we will analyze how different selection panels confront issues such as Halo bias, linguistic bias, and cognitive bias.

An exciting new window into the circumgalactic medium (CGM) has opened up with the recent observations of the thermal and kinetic Sunyaev-Zel’dovich (SZ) effects on galactic spatial scales. I will present the ongoing efforts to extract these galaxy scales SZ signals in data from the Atacama Cosmology Telescope. I will show how these observations are currently being used to constrain important physical processes, like feedback, that govern galaxy formation. Additionally, I will present some puzzles these observations pose to state-of-the-art cosmological simulations. I will conclude by highlighting the expected rapid growth in such SZ
observations over the next decade with the upcoming millimeter and sub-millimeter focused experiments, like the Simons Observatory, CCAT, and CMB-S4.

Observing campaigns have revealed a great diversity in exoplanetary systems whose origin is yet to be understood. How and when planets form, and how they evolve and interact with their birth environment, the protoplanetary disks, are major open questions. Protoplanetary disks evolve while planets are forming, implying a direct feedback between the processes of planet formation and disk evolution. These mechanisms leave clear imprints on the disk structure that can be directly observed. In this talk, I will review recent observational results on protoplanetary disks, in particular those from the exoALMA Large Program, the first sub-millimeter planet hunting campaign. With exquisite molecular line observations, the velocity structure of fifteen protoplanetary disks revealed a variety of kinematic perturbations possibly due to embedded protoplanets, (magneto-)hydrodynamical instabilities or winds.

An efficient coupling between the energy released by Active Galactic Nuclei (AGN) and the interstellar medium (ISM) of their host galaxy can generate kpc scales outflows which may regulate the rate at which stars can form and ultimately influence the growth of the galaxy.  These AGN driven outflows include gas in various phases (ionized, atomic, molecular) but at z>1, due to the limitations of current instrumentation, we are usually forced to adopt a single-phase (ionized) view of the outflow phenomenon which may lead to wrong estimates of their extent, mass and energetics, therefore ultimately misinterpreting their relevance for galaxy evolution. JWST/MIRI can be used to overcome some of the previous limitations, and to map the mid-infrared ro-vibrational H2 lines to complete the multi-phase characterization of the ISM. We report some recent MIRI/MRS observations that allow us to detect hot-molecular gas in the host a bright quasar at z~2 with already well characterized kinematics of the ionized gas showing a galactic scale AGN-driven outflows. We will compare this newly detected gas component with the other phases of the ISM and with predictions from simulations. 

Almost all accreting black hole and neutron star X-ray binary systems (XRBs) exhibit prominent brightness variations on a few characteristic time-scales and their harmonics. These quasi-periodic oscillations (QPOs) are thought to be associated with the precession of a warped accretion disc, but the physical mechanism that generates the precessing warp remains uncertain. Relativistic frame dragging (Lense-Thirring precession) is one promising candidate, but a misaligned magnetic field is an alternative, especially for neutron star XRBs. Here, I will present the discovery of 5 accreting white dwarf systems (AWDs) that display strong optical QPOs with characteristic frequencies and harmonic structures that suggest they are the counterpart of the QPOs seen in XRBs. Since AWDs are firmly in the classical (non-relativistic) regime, Lense-Thirring precession cannot account for these QPOs. By contrast, a weak magnetic field associated with the white dwarf can drive disc warping and precession in these systems, similar to what has been proposed for neutron star XRBs. The presented observations confirm that magnetically-driven warping is a viable mechanism for generating QPOs in disc-accreting astrophysical systems, certainly in AWDs. Additionally, they establish a new way to estimate magnetic field strengths, even in relatively weak-field systems where other methods are not available. And furthermore, I will discuss the possible new application of the model to explain mHz QPOs in Ultraluminous X-ray Sources (ULXs).

Stellar evolution and planet formation could meet when it comes to post-asymptotic giant branch (post-AGB) binary systems. In such systems, the evolved pair of stars are surrounded by stable, massive circumbinary discs. These discs show surprisingly many similarities with protoplanetary discs around pre-main sequence stars, including dust mass, Keplerian rotation, infrared excesses, and the disc physics near the dust sublimation rim. These similarities raise the question whether a second episode of planet formation processes are taking place in these discs around evolved stars. Studying these discs can bring significant implications on our understanding of circumstellar disc physics and this in a peculiar parameter space (short disc lifetime, high stellar luminosity, different disc formation mechanism and environment). I will show results of observing campaigns mainly with the VLTI to probe the inner regions of these discs, how these can help to uncover the disc physics, and how we can link the circumstellar discs across the stellar evolutionary stages.

For more than 50 years mankind has invested in human space exploration. Since then, astronauts have orbited the Earth and landed on the moon, installed the Hubble Space Telescope, and expanded the scope of exploration in unprecedented ways. In addition to all the experiments and technological advances these missions have given us a completely new perspective on our home planet seen as a ‘pale blue marble’ in space. This is the essence of the Overview Effect.

The chemical evolution of high-redshift galaxies is key to understanding galaxy formation. Using data from the MARTA Survey and deep JWST/NIRSpec observations, we detected multiple, faint auroral lines in star-forming galaxies at z∼2–3, enabling precise electron temperature-based metallicities during 'Cosmic Noon,' the peak epoch of star formation. Our results provide a recalibration of strong-line diagnostics and refine the sulfur and oxygen temperature relations

The importance of mental health and the need for finding the right balance between work and life is something that is rarely, if ever, talked about, especially in academia. Yet, many students and faculty alike feel the stresses of modern life and suffer from the pressure to constantly perform, achieve and produce. According to the American College Health Association, students reported stress, anxiety, sleep trouble and depression as the top four impediments to academic achievement, and 9 of the 10 top factors are mental health and/or coping skills related. The importance of maintaining mental health has never been more obvious and urgent. The benefits of mindfulness to body, mind, and emotional well-being are well established by medical research and include greater peace of mind, happiness and the ability to relax from the stresses of current times. In this workshop, Dr. Vardha N. Bennert will present an introduction to mindfulness and meditation. She will guide participants in short mindfulness practices that can be used as tools in everyday life. She will also facilitate group discussions.

Bio: To balance her work as a teacher and researcher in physics and astronomy, Dr. Bennert has been practicing various forms of meditation and body-awareness practices (such as Tai Chi, QiGong, Yoga and conscious dance) for the past 20+ years of her life and has also participated in numerous personal growth workshops. Throughout her career, she has been approached by students struggling with finding a healthy work-life balance, resulting in uplifting conversations that inspired her to offer workshops like this one.

Format: pedagogical lecture plus in-depth discussion

I will summarize 3 recent papers about galaxies at z>=10, and the Ho tension. I will then discuss, without offering solutions, whether such results place the standard Cosmological model en course towards the rocky shores of a funtamental(s) crisis.

There is now a distinct possibility that neutral atoms and even molecules can exist in the extreme environments near the Supermassive Black Holes (SMBHs) that power the Active Galactic Nuclei (AGN), even in the absence of dust and the presence of strong UV/X-ray radiation fields. The corresponding spectral lines may yield  new spectral windows to AGNs as well as new tests of General Relativity in strongly curved Spacetimes.

Studies of protostellar accretion and outflow processes have been revolutionized by the incredible power of JWST. Investigating Protostellar Accretion (IPA) is a Cycle 1 JWST program that targeted 5 young, inclined protostars in their primary accretion phase, spanning the mass spectrum, with the NIRSpec and MIRI MRS IFUs. The data enables exploration of the signatures of accretion and outflow through spectral mapping of the inner regions of protostars with high spatial and spectral resolution. The rich datasets clearly show the nested morphology of protostellar outflows just hundreds of au from the driving source. These data consistently show collimated jets traced by shock-ionized [Fe II], surrounded by narrow shells of warm H2, within wide-angle outflow cavities traced by the scattered-light continuum. H2 is observed filling the shells, showing probable evidence of molecular winds or expanding bow shocks. Shocked knots in the jets are detected in molecular, neutral atomic, and ionic tracers. Preliminary results from a morphological and kinematic analysis of the collimated jets from three of the protostars show evidence of wiggles and bends in the jets, as well as asymmetries between jet and counterjet. Using the jet velocities found from the higher spectral resolution MIRI MRS, the mass and momentum outflow rates are estimated. These data provide the clearest picture yet of protostellar outflows during the deeply-embedded primary accretion phase.