Seminars and Colloquia at ESO Garching and on the campus

Galaxy clusters, representing the peaks in the cosmic density field, serve as an independent and powerful tool for investigating the evolution of cosmic structures. The strategic identification of these clusters through multi-wavelength surveys is essential for advancing our understanding of gravitational theory, general relativity, and cosmological models. A significant milestone was achieved with the successful launch of eROSITA in July 2019. The German-built eROSITA X-ray telescope, on board the Russian-German Spectrum-RG (SRG) mission, operates within the 0.2-8 keV range and has produced the largest ICM-detected catalogs of galaxy clusters and groups through its first All-Sky Survey. With over 10,000 confirmed clusters, the survey is pivotal in refining cosmological parameters when combined with the data from optical surveys like DESI Legacy, DES, HSC, and KIDS. These parameters are constrained at a percentage level through the evolution of the cluster mass function, representing a significant leap forward, exhibiting a 5-9 times improvement compared to previous cluster surveys. In this talk, I will outline the constraints on fundamental cosmological parameters, neutrino masses, and general relativity derived from the first eROSITA All-Sky Survey. Additionally, I will present eROSITA's significant detection of warm baryons within cosmic filaments identified by optical surveys and the implications for our understanding of AGN feedback in group-size haloes. I will summarize the value-added products made available to the science community by the eROSITA consortium's data release.

The formation histories of galaxies are encoded in their stellar dynamics. Using orbit-based dynamical modeling, it is possible to construct orbit distributions for observed galaxies, allowing us to disentangle their constituent dynamical components. This talk will focus on my contribution to the ongoing work of improving the orbit reconstruction with the orbit-superposition modeling software DYNAMITE (developed at the University of Vienna). Firstly, I will discuss biases in the dynamical inference caused by the type of stellar kinematics we use as input, comparing models based on the parametric Gauss Hermite expansion and those based on non-parametric kinematic recoveries using the Bayes-LOSVD software. Secondly, I will talk about ongoing efforts to include a more physically-motivated prior in the modeling to pave the way for more robust uncertainty quantification in the orbit space.

Supermassive black holes (BHs) are ubiquitous in the center of massive galaxies. When actively growing through accretion, Active Galactic Nuclei (AGNs) become some of the brightest objects in the universe. It has been two decades that relations between BH mass and the properties of their host galaxies (such as luminosity, stellar mass and stellar velocity dispersion) were first discovered. Interpreted as evidence for a co-evolution between BHs and galaxies, these scaling relations remain a hot topic for contemporary studies with many open questions remaining, including the role of AGN feedback or hierarchical merging, and the nature of the host galaxies. Studying the co-evolution as a function of cosmic history can shed light onto origin and fundamental drivers, but relies on AGNs for which host-galaxy properties are intrinsically difficult to measure, especially at higher redshift. Thus, a local baseline of the MBH-scaling relations for AGN is the key. I will discuss recent progress made possible through integral-field spectroscopy that allows for a robust measurement of stellar-velocity dispersion. While reverberation mapping has been the gold standard for BH mass measurements in AGNs, traditional methods yield only sample-average recipes for BH mass estimates. Recent advances include resolving the broad emission around AGNs spatially: (i) by dynamical modeling of reverberation-mapped data and (ii) through spectro-astronometry with GRAVITY/VLTI. The combination of both leads not only to a full 3D view of the BLR, important for accurately measuring BH mass, it even allows to measure absolute geometric distance to the AGN. In this talk, I will review our understanding of the nature and origin of the scaling relations between supermassive black holes and their host galaxies, and outline new directions.

The evolution of galaxy clusters is highly influenced by the dynamics of the Intracluster Medium (ICM), which governs crucial mechanisms. This includes mixing, turbulence processes, and galaxy interactions within the cluster environment. Among the factors influencing the ICM dynamics, the impact of viscosity is still under debate. Understanding the effect of viscosity on the evolution of galaxy clusters is fundamental for comprehending gas properties and the underlying dynamics within the ICM.

By conducting a thorough study, we aim to highlight the implications that viscosity introduces compared to inviscid simulations. These implications encompass morphological differences, larger density fluctuations, and the intricate interplay of the magnetic field amplification, among other fundamental effects. Our results challenge prior assumptions, especially concerning the constraints on viscosity within the ICM. This study is expected to enhance our understanding of ICM dynamics and contribute to our knowledge of galaxy cluster evolution.

Relativistic jets launched by supermassive black holes are among the most extreme particle accelerators in the universe. The emission from these jets is variable from radio to very-high-energy gamma-rays on timescales ranging from years to minutes. The variability patterns are extremely complex, but carry the imprint of the complex phenomenon of particle acceleration and contribution from different emission mechanisms and regions within the jet. Cherenkov Telescope Array Observatory (CTAO) will have superior capabilities to study the variability at the very highest energies. It will also allow us to study a significantly larger population of extragalactic jets than what is possible with current instruments. In this talk, I will present a few showcases to demonstrate CTAO capabilities on studies of extragalactic jets with a special focus on studies that have synergies with ESO. 

Astronomical objects are the best ambassadors for understanding the formation and evolution of both small- and large-scale structures of the Universe. We are constantly eager to learn how our Solar System and other star systems formed and how they evolve over time. Meteorites, in particular, serve as valuable messengers, revealing insights into the origins of the Solar System and even hinting at its ultimate fate. Since they come from outer space, they carry clues about their distant homelands. In this AfnA talk, we will explore fascinating stories about meteorites and examine practical examples, including the second largest meteorite in Africa, “Kimondo cha Mbozi” (a Swahili word meaning ‘’Meteorite of Mbozi’’). Could it be seen as a "QR code" to its place of origin? How was and is it perceived in its new homeland?

All these questions, and more, will be interactively explored during the talk and finally, make the entire audience chat with “kimondo cha Mbozi”. 

Everyone at ESO, but especially non-astronomers, is invited. Guests are, as usual, welcome.

Precise knowledge of focal plane point spread function (PSF) is essential in many scientific data post-processing applications, including deconvolution, as well as precise astrometry and photometry. Moreover, as the culmination of the imaging process, PSF “absorbs” the cumulative effect of all contributors along the optical path, thus encoding valuable information about the optical system that can be utilized for diagnostics and calibration.

In this talk, I will introduce two PSF-based techniques for adaptive optics (AO) system calibration and scientific data post-processing.

The first part will focus on a method for retrieving quasi-static aberrations from focal-plane PSFs. The approach was tested on-sky using the low-order wavefront sensor of the MUSE Narrow-Field Mode (NFM). The results demonstrated the ability of the method to measure non-common path aberrations effectively under real observing conditions.

The second part will introduce a technique for realistic modeling of AO-corrected science PSFs using reduced AO telemetry and atmospheric monitoring data. The method was validated with on-sky data from the MUSE NFM and SPHERE IRDIS instruments, achieving small discrepancies between the predicted and observed PSFs. In addition, the proposed technique demonstrated the ability to accurately predict the wavefront errors induced by the low-wind effect based solely on reduced AO telemetry and atmospheric data.

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. 

The most underdense regions of the Universe are the home of a population of gas-rich and low-metallicity dwarf galaxies. These galaxies could be the key to understand the earlier stages of hierarchical assembly within the ΛCDM. These galaxies present the exciting puzzle of how their stellar masses assembled — through gas accretion from the IGM, mergers, or a combination of both? The few observational and theoretical studies dedicated to this topic show conflicting results; during this discussion, I will outline an ongoing project that aims to address these questions by analyzing their neutral gas content and metallicity gradients, providing new insights into the assembly history of these galaxies.

Nowadays it is possible to observe planet forming environment with incredibly high spatial and spectral resolution thanks to ALMA telescope. Recently, protoplanetary disc kinematics gained a lot of interest, as it directly probes disc structure, unveils planet disc interaction and tests the presence of hydrodynamical instabilities.

exoALMA is an ALMA large program, whose aim is to characterise the kinematics of protoplanetary environments with unprecedented spatial and spectral resolution. In this talk I will present my work within exoALMA collaboration, which involves modelling the rotation curves to constrain fundamental properties such as disc mass, stellar mass and scale radius. The knowledge of such quantities allows to investigate disc composition, to compare with thermochemical models and to constrain the efficiency of angular momentum transport.

Despite the crucial role that massive stars have in the evolution of their host galaxies, the processes and the stages that lead to their formation are not yet completely understood. One of the biggest uncertainties comes from the lack of a solid diagnostic tool to classify massive young stellar objects (MYSOs) according to their evolutionary stage. Currently, the only evolutionary indicator for MYSOs is L/M (bolometric luminosity to envelope-mass ratio), based on a theoretical classification scheme from the low-mass SF model. However, this method is severely hampered by the extreme extinction of high-mass star forming sites and by the poor resolution of existing facilities in the infrared (IR) regime which limits the accessible scales to those of entire proto-clusters. My PhD project proposes a novel approach to investigate the mid-IR properties of single members of proto-clusters using several transitions of different molecules sensitive to the radiation field of MYSOs through ALMA observations. In this presentation, I will show the novel method proposed and the analysis on a pilot sample of well known and characterised massive proto-clusters in different evolutionary phases.

Galaxies live in a complex ecosystem, driven by the interplay between energy derived from stars and a central supermassive black hole. The interstellar medium and star formation properties of AGNs provide key insights into the role that black holes play in the lifecycle of galaxies. AGN feedback is often invoked as a key physical mechanism to self-regulate star formation and black hole accretion. Is this mechanism truly effective?  How to tell?  I will introduce new methods to measure the cold gas content, star formation rate, star formation efficiency, and stellar mass in AGN host galaxies, near and far. These methods are used in a series of experiments designed to test the efficiency of AGN feedback and the coevolution of black holes and their host galaxies across cosmic time.

Hypervelocity stars (HVSs) are stars which have been ejected from theGalactic Centre at velocities of up to a few thousand km/s. They are tracers of the Galactic potential and can be used to infer properties of the Galactic Centre, such as the initial-mass function and assembly history. HVSs are rare, however, with only about a dozen promising candidates discovered so far. In this informal discussion, I will describe our observational survey to discover additional HVSs and characterise their population properties. I will furthermore present our findings and show how these results help us understand the centre of our Galaxy. In particular, I show that the number of HVSs in our survey is highly constraining for the ejection rate of HVSs and the mass function of their progenitor population.

In this talk, I describe various projects aimed at understanding some aspects of the structure and evolution of the Milky Way Galaxy, using numerical simulations. Included are a study of the evolution of the pattern speed of the bar, accounting for the interstellar medium, the prolate and tilted aspect of the inner halo and its relation to the warp of the Galactic disk, and the evolutionary history of the disk as probed by red giant stars from Gaia and the IllustrisTNG cosmological simulations. Finally, I discuss limitations of the current generation of cosmological simulations and an ongoing effort to enhance the physical fidelity of the modeling.

A surprising recent result from the study of stellar rotation is that a related observational space can be constructed and stratified such that the age of a cool star can be inferred by placement therein. This procedure has distinctive parallels to the situation in geological stratigraphy. My talk will discuss how this felicitous situation came to be and how it could potentially be further developed.

Educational research has shown that compared to the traditional lecture style where students are primarily listening and taking notes, active learning methods not only produce higher student achievement and retention, but even increase positive attitudes and self-esteem. In active learning, a significant fraction of class time is spent on students working on activities that require them to be processing and applying information in a variety of ways, such as answering in-class conceptual questions, completing worksheets and discussing and solving problems in groups. The tasks are designed to promote analysis, synthesis, and evaluation of class content, simulating aspects of expert reasoning and/or problem-solving skills. Timely and specific feedback from both peers and the instructor provides guidance. In this talk, Dr. Vardha N. Bennert will summarize key findings of education research and present several active learning techniques. She will also discuss the “Learning-Assistant” (LA) model in which undergraduate students, who have taken the class previously and who receive special concurrent preparation, facilitate group interactions. While the talk will focus on introductory-level astronomy classes for non-science majors, the general active learning strategies are easily transferrable to a wide range of classes at various levels.

The measurement of rotation curves led to big discoveries in astronomy, like the proposition of dark matter halos around galaxies. With the emergence of ALMA, it is now similarly possible to measure the rotation of gas in protoplanetary disks, which are several orders of magnitude smaller than galaxies. While the overall motion of the gas around newborn stars is Keplerian, with high spectral resolution molecular line observations, we can trace small-scale velocity perturbations caused by local pressure variations in the disk, possibly due to embedded planets.In the talk, I will discuss how we can observe gas rotation in planet-forming disks and what we can learn from studying the deviations from Keplerian rotation. In particular, I will present results from the rotation curve study for the disks of the exoALMA Large Program. We find that substructures in the deviation from Keplerian rotation are ubiquitous in our sample, on both small and large scales, and can reach up to 15 percent in the most extreme cases. Interestingly, the majority of the dust continuum rings and gaps are co-located with pressure maxima and minima, respectively. Finally, I will compare the presented results with the predictions from the theory and put them into the bigger picture of planet formation.

The numerous discoveries of z>10 ultraviolet bright galaxies with the James Webb Space Telescope have sparked a discussion about the nature of star formation and the interstellar medium in galaxies at early times: which physical processes drove their appearance and need to be included in our models to explain them? Are these galaxies characterised by such high gas densities that stellar feedback does not hinder star formation, or do radiation-driven outflows effectively clear the dust from star-forming regions? Is their star formation highly stochastic, or do their stellar populations exhibit a higher abundance of massive stars?
We have investigated how assuming stellar initial mass functions (IMF) whose top-heaviness depends on galactic properties and/or time shapes the evolution and properties of early galaxies. To this end, we have integrated such evolving IMFs into the Astraeus framework, which couples an N-body simulation with a semi-analytical model for galaxy evolution and a semi-numerical model for reionisation. Our integration included adapting the descriptions for supernovae feedback, metal enrichment, and ionising and ultraviolet radiation emissions. 
In my talk, I will discuss how two different parameterisations of evolving IMFs affect the relations between galactic properties (e.g. stellar mass, star formation rate, ultraviolet luminosity, gas-phase metallicity), the ultraviolet luminosity functions at z=6-15, and the morphology of the ionised regions in the intergalactic medium during reionisation, compared to a constant Salpeter IMF. I will also explain which galaxies require a more top-heavy IMF to match JWST observations at z>10.

To address the need for a more realistic comparison between theory and observations, this talk will describe the creation of a synthetic spectroscopic dataset derived from the TNG50 cosmological simulation, tailored for WEAVE-StePS observations. I will compare the star formation histories of these galaxies, obtained through a full spectral fitting analysis, with their merger histories derived from the simulation. This strategy allows for a proper comparison between observed star formation histories and those inferred from cosmological simulations, highlighting potential systematics and observational biases.
This analysis serves as a fundamental benchmark not only for the forthcoming WEAVE observations but can also be easily generalized to any facility worldwide, providing the community with realistic mock galaxies to compare against observed datasets and explore optimal strategies for future extragalactic campaigns.
In the second part of the talk, I will focus on how to utilize simulations when studying star formation histories (SFH) in different environments. My project at the European Southern Observatory (ESO) aims to assess the role of the environment in shaping the SFH of galaxies by comparing data from various clusters in the local universe. The project is divided into two main aspects: analyzing observational data and comparing it with simulations.
We have already analyzed publicly available archival ESO data, such as Atlas3D (Cappellari et al., 2011) for the Virgo cluster and Fornax3D (Sarzi et al., 2018) for the Fornax cluster. While these observations provide a snapshot of the present-day universe, cosmological simulations offer comprehensive insights into the merger history, quenching, and rejuvenation processes of each galaxy. This work aims to uncover the physical processes that lead to specific SFHs, emphasizing the importance of an "apples-to-apples" comparison between observations and simulations.

It is now commonly accepted that stars are mainly born multiple. Half of all field stars belong to multiple stellar systems, a number that is even higher at younger ages. Thus, multiple stellar systems are rather the norm than the exception. Despite being of key importance, the impact of stellar multiplicity on how planets form remains poorly understood.

Indeed, protoplanetary discs in multiple stellar systems are subject to gravitational perturbations from surrounding stars, which alter their kinematics and can lead to complex dynamical behaviours. Stellar multiplicity also imprints a variety of sub-structures in protoplanetary discs (cavity, spiral arms, …). These sub-structures can take the form of high-density regions that may locally promote dust growth. Conversely, stellar multiplicity can excite high collisional velocities between dust grains, hindering their growth. The way these barriers are overcome remains elusive.

In this talk, we will study the dynamics of discs in multiple stellar systems following the example of V892 Tau. Then, we will examine the properties of dust grains in young multiple stellar systems mainly based on sub-millimeter/millimeter observations. After that, we will see how hydrodynamical simulations can predict the grain properties in these complex environments, linking the simulated disc dynamics to the observed grain properties. With numerical results connecting well to the observations, I will conclude by discussing the implications for planet formation in multiple stellar systems.

A growing number of surprisingly massive galaxies are now being found in the first ~billion years after the Big Bang that push the limits of theoretical predictions within Lambda-CDM. Unusually bright high-redshift galaxies discovered by JWST challenge our most fundamental models of how fast stars form. Some of them contain overly massive black holes whose formation is uncharted. Massive dusty starbursts found with ALMA are requiring new explanations about early dust production. The spatial distribution of massive galaxies within large scale structure may be more highly clustered than expected. I will present recent results from the COSMOS-Web survey and related efforts to find the rarest galaxies at early times (UV-luminous, dust-obscured, and little red dots) that help place constraints on our interpretation of their growth and buildup at early times.

A large population of AGN pairs residing in the same galaxy - the so-called dual AGN - is expected to exist z > 0.5. These systems constitute the parent population of the merging black holes (BHs), making their number and properties a key starting point for theoretical predictions on the level of the gravitational wave (GW) background and the event rate investigated in pulsar timing array (PTA) experiments and by the future LISA mission. Moreover, examining the properties of dual AGN ( e.g. the mass function of the two merging BHs, the distribution of separations) and their fraction with respect to the total AGN population, allows us to test numerous theoretical predictions on galaxy formation and evolution, and study how these properties evolve with redshift. For all these reasons, dual AGN are of paramount importance to establish a comprehensive census of BH growth.

Nonetheless, our knowledge on dual AGN has been limited so far, with only few systems detected at sub-arcsec separations. The all-sky survey Gaia is now playing a pioneering role in the search for dual candidates. In this talk, I will present the strengths and weaknesses of the innovative 'Gaia multi-peak' (GMP) technique, which successfully selects a large number of multiple candidates at separations between 0.15" and 0.7" (~1 kpc at z> 0.5). However, additional follow-ups are fundamental to shed light on the real nature of these multiple objects, which may be confirmed as dual AGN or discovered to be lensed systems. I will hence showcase spatially resolved spectroscopy and high spatial-resolution imaging obtained with HST and several ground-based AO-assisted instruments (Keck, VLT, and LBT) of the first spectroscopic sample of confirmed dual AGN selected via the GMP technique. I will describe the physical properties of these dual AGN (e.g. masses, luminosity functions), and highlight the importance of collecting larger and larger samples of dual AGN to conduct a statistical study and finally test model predictions on galaxy evolution.

Colleagues, young and old, erudite and wise, or even wiser, repeatedly state that forbidden lines get quenched at high electron densities. It is stated in textbooks and papers, and talked of in talks. But what is this ‘quenching’? Does it exist? Going back to the identification of Nebulium as emission by forbidden lines of ionised Oxygen by Ira Bowen in 1927 ambiguous language and, sadly ambiguous physics, has been used and sometimes even taught on the subject of the emission of forbidden lines in the high electron density regime. The discussion shall review the historical path to confusion and will try to right wrongs or as a minimum propagate doubt.

I will present recent and ongoing explorations regarding cold clouds in the circumgalactic media of (simulated) z=0 Milky Way-like galaxies. We find that these CGMs are typically filled with >~100s-1000s of such cold gas structures, possibly analogs of high-velocity clouds (HVCs) observed in the Milky Way sky. These objects primarily originate as a result of cold gas outflows from the central galaxy and/or precipitation of the warm-hot phase of the CGM. Clouds arising as a result of stripping of cold gas from satellites are rare in our sample (<5%). Lastly, we find that properties of clouds are diverse, and may furthermore depend closely on their source of origin.

The Orion Bar, situated in the nearest massive star formation regions, has been successfully observed in imaging and spectroscopy as part of the JWST Early Release Science program, PDRs4All (https://pdrs4all.org/). This allows to study with great precision the effects of radiative feedback from massive stars on interstellar molecular clouds and proto-planetary disks in the line of sight, and the dominant physical and chemical processes that lead to the infrared emission that JWST will detect in many astrophysical environments.  This presentation overviews the observations of PDRs4All and discuss how FUV radiation change almost all the physics and chemistry.  In particular, I will highlight the importance of still little-used microphysical/chemical processes such as the chemistry of excited molecular hydrogen, with direct consequences on the water and carbon chemistry.

A pedagogical lecture plus in-depth discussion

Could some dwarf galaxies exist without dark matter? In this informal discussion, I’ll talk about a “recipe” for potentially identifying dark matter-free dwarf galaxy candidates, based on shared features found in systems like NGC 1052-DF2, DF4, and FCC 224, suggested to be dark matter deficient. These galaxies share key characteristics—such as unusually bright globular clusters, slow rotation, and similar ages for their stars and globular clusters, which make them stand out. By recognizing these signatures, we can pinpoint more potential dark matter-free dwarfs and reinterpret the role of dark matter in the formation of these galaxies.

Majidi, F. Z. (1); Bradley, L. (2); Ma, S. (2,3); Saba, A. (2,3); Tinetti, G. (2,3);

Stotesbury, I. (2); Edwards, B. (3); Savini, G. (3); Tessenyi, M. (2)

(1) Blue Skies Space Srl., Milan, Italy; (2) Blue Skies Space Ltd., London, UK; (3) University College London, Dept of

Physics & Astronomy, London, UK

Mauve is a satellite equipped with a 13-cm telescope and a UV-Visible spectrometer (with an

operative wavelength range of 200-700 nm) conceived to measure the stellar magnetic activity and

variability. The science program will be delivered via a multi-year collaborative survey program,

with thousands of hours each year available for long baseline observations of hundreds of stars,

unlocking a significant time domain astronomy opportunity. Mauve’s mission lifetime is 3 years

with the ambition of 5 years, and will cover a broad field of regard (–46.4 to 31.8 degrees in ICRS)

during this period.

This facility was conceived to support pilot studies and new ideas in science and is fully dedicated

to time-domain astronomy. The main surveys to be executed by Mauve are long baseline

observations of flare stars, Herbig Ae/Be stars, exoplanet hosts, as well as contact binary variables

(RS CVn variables, symbiotic stars, Algol-type stars, etc.). Besides these major science themes, the

spectrometer’s data can be utilized to support and complement existing and upcoming facilities as a

pathfinder, or conduct simultaneous/follow-up observations.

The magnetic activity of the Sun and solar-like stars is driven by an  αΩ-dynamo, according to which the combination of differential rotation  and convective motions of the outer atmospheric envelope continuously  regenerates the magnetic field that manifests as powerful optical, UV  and X-ray radiation. M dwarfs are also known to be magnetically  active, but the physical mechanism is poorly understood. In addition,  M dwarfs host planets, whose formation and evolution is strongly  influenced by the host star's X-ray emission.  In this talk, I present an overview of the X-ray activity of M  dwarfs and its dependencies on mass and rotation, based on the study  of the largest and most uniform sample of new X-ray data and rotation  periods combined with results from the literature.  Then, I will show the results of the comprehensive study of the  X-ray variability of the benchmark planet host Proxima Centauri, long  known as a flare star and, due to its proximity, a source of very  bright X-rays.With the discovery of a planet in its habitable zone in 2016, Proxima  Centauri has become a key target for studies of stellar activity and  its impact on planets.  By analyzing a dataset of dedicated XMM-Newton observations combined  with data from the four eROSITA all-sky surveys, I obtained the  coronal temperature at different activity states of Proxima Centauri,  which allowed for the first time to study the relation between coronal  temperature and X-ray luminosity based on the variability of a single  star.The coronal emission of Proxima Centauri is found at higher  temperatures than solar-type stars and, at a specific value of X-ray  luminosity, exhibits a temperature spread likely caused by the amount  of electric current involved in the coronal heating mechanism that  causes the formation of more complex magnetic loop structures.These results provide new insights for the computation of evolutionary  models of planetary atmospheres, which are constantly affected by  stellar magnetic activity that tends to promote or destroy their  habitability.

Supermassive black holes (SMBHs) are ubiquitous in the center of massive galaxies and thought to co-evolve with their host galaxies, as evidenced by correlations between the mass of the SMBH and  the properties of their host galaxies. Of the observed MBH-host-galaxy scaling relations, the MBH-sigma relation is of greatest interest. Not only has it traditionally been used to determine the virial factor for reverberation-mapped (RM) AGNs, it is also considered the tightest, and thus fundamental. However, some studies conclude that it only exists for elliptical galaxies and classical bulges. Moreover, sigma can vary on average by up to 40% across definitions common in the literature, depending on e.g., aperture size and disk contribution, cautioning the use of long-slit spectroscopy or fibers. Over the last couple of  years, our team has obtained IFU data with state-of-the-art instruments (VLT/MUSE and Keck/KCWI+KCRM) for the RM sample with directly measured MBH. Thanks to the superb IFU data yielding spatially-resolved velocity dispersion measurements across the galaxy, the contribution of disk rotation to sigma can be removed. After this correction, spiral galaxies indeed follow the same MBH-sigma relation as quiescent galaxies, suggesting that the dynamically hot disk component coevolves with the SMBH. However, the correlations are tightest on scales of the bulge. After accounting for different MBH distributions, we can demonstrate – for the first time – that AGNs follow the same MBH-sigma and MBH-M_dyn relations as quiescent galaxies. In other words, with accurate sigma measurements, the relations are robust, regardless of host-galaxy morphology. 

The physics of gravitational instability—which links primordial density fluctuations to the formation of cosmic structures—provides the foundations for the theory of galaxy and cluster evolution. However, providing a sound description of the fate of baryons that reside within large gravitational potential wells has proven challenging. In this talk, I will present the research I conducted during my PhD—which, hopefully, I will have successfully defended the day before—focusing on the interpretation of (sub-)mm ALMA observations of the most massive gravitationally bound objects in the universe at their respective epochs: the first galaxies (at z > 10) and galaxy clusters (at z ≈ 2). I will also discuss ongoing work on a new simulation tool, named maria, designed to forecast (sub-)mm observations for current and future large single-dish facilities. Maria will be particularly insightful for next-generation sub-mm experiments like AtLAST, enabling forecasts of resolved Sunyaev-Zeldovich measurements and optically unbiased line surveys to identify high-z galaxies. These forecasts can then be directly linked to instrument and telescope design specifications, setting the stage for the future of (sub-)mm observations of cosmic structure growth.

Hooke’s law, characterizing the linear force exerted by an elastic spring, was published in 1678 in “De Potentia Restitutiva, or of Spring. Explaining the Power of Springing Bodies”. Only nine years later, in 1687, Newton published his “Philosophiæ Naturalis Principia Mathematica”, which presented for the first time the famous inverse square force law of gravitation. At that time, according to Chandrasekar’s reading of the Principia, both Hook and Newtown, were aware about a duality between these two forces laws. This Hooke-Newton duality in essence states that the orbits of classical motion for both can be mapped into each other.     In this informal discussion we will: 1. Revisit and explicate this almost-350-year-old duality. 2. Learn about its generalization to arbitrary power-laws (Bohlin 1911). 3. Speculate about its possible relevance and application in general relativity.

We employ natural language processing algorithms with attention, repurposed to receive QSO spectra to predict unseen spectra, broad lines, and super massive black hole masses. We find that the trained algorithm is able to reproduce with high significance masked broad lines and/or continua in QSO spectra, highlighting an ability to learn from and leverage physical information imprinted amongst the entire spectrum. A key implication is that this information may help to refine physical properties such as single-epoch black hole masses. We tested the algorithm’s ability to directly predict black hole masses, with no spectral fitting or decomposition, finding reasonable success to reproduce single-epoch prescriptions. Finally, the algorithm is able to reconstruct broad UV lines such as C IV and Ly-alpha in the presence of broad absorption lines or intervening IGM. We will discuss the attention mechanism, which allows us to peek inside and probe what information is being used to make the above predictions and several broad future applications that we envision.

Recent JWST observations of Type Ia supernovae (SNe Ia) during the late-time nebular phase (>200 days post explosion) have paved the way for spectroscopic studies extending all the way to the mid-infrared range, and with it the hope to better constrain SN Ia explosion mechanisms. The first SN Ia spectrum obtained with JWST unveiled for the first time the 2.5-5 micron wavelength range and revealed kinematic offsets of several 1000 km/s in a subset of emission lines, hinting at possible ejecta and composition asymmetries. The second SN Ia displayed a prominent line due to once-ionised neon ([Ne II] 12.8 micron), never observed before in spectra of such events and associated with the violent merger of two WDs. I will present the results of radiative-transfer simulations that were used to interpret these data, and discuss the impact of ejecta asymmetries, ionisation effects and uncertainties in the atomic data on the predicted spectra. These models suggest that key physical ingredients are missing from either the explosion models, or the radiative-transfer post-processing, or both. Nonetheless, they also show the potential of the near- and mid-infrared to uncover new spectroscopic diagnostics of SN Ia explosion mechanisms.

Historically, the search for the inter-galactic medium (IGM) motivated the search for  the Far Ultraviolet (<0.2 micron; FUV) background which in turn led to a number of experiments and missions.  Decades later the focus shifted to FUV as the primary heating and ionizing agent of the atomic phases (warm and cold neutral medium).  On the observational side, it was realized that at high Galactic latitudes, the diffuse FUV has three components: FUV light from hot stars in the Galactic plane reflected by dust grains (diffuse galactic light or DGL), FUV from other galaxies (extra-galactic background light, EBL) and a component of unknown origin.  This view has been amply confirmed by later GALEX observations. During the eighties, there was conisderable discussion that decaying dark matter particles produced FUV radiation.  In my talk I systematically investigate production of FUV photons from all major sources capable of producing FUV emission. I conclude that two thirds to perhaps all of the third component can be explained by the sum of Galactic Hot Ionized Medium (line emission), two photon emission from the  Warm Ionized Medium, low velocity shocks in the Galaxy and Lyman fluorescence in the Solar System (the interplanetary medium and  the exosphere of Earth).

Four ground-based multi-wavelength facilities are being developed and implemented by the Italian National Institute of Astrophysics under EU sponsorship, in support of the Cherenkov Telescope Array project.   Among them is a polarized filter for  the VST/Omegacam, that will be suited for deep optical polarimetric surveys.

At least a significant fraction of classical Be stars were formed by past mass transfer in interacting binaries, in which they acquired the necessary excess angular momentum to spin up and form the characteristic self-ejected circumstellar disks. Post-mass-transfer Be stars typically have stripped companions of the subdwarf OB-type (sdOB), which can further evolve into white dwarfs (WD) or if massive enough into neutron stars to become high-mass X-ray binaries. Although sdOB and WD companions are expected to be common, they are very hard to detect due to their low masses and luminosities compared to the Be star primaries. Only about two dozen hot sdO companions have been detected by (far-UV) spectroscopy, with sdB and WD companions being even more elusive. In a still ongoing interferometric program on the binarity of Be stars with the CHARA Array and the VLTI, we directly detected several bloated pre-subdwarf companions, several sdO companions and we confirmed the first sdB companion with temperature similar to that of the host Be star. We also obtained astrometric orbits of these binaries with further observations, enabling the determination of their dynamical masses, and providing a firm physical basis for the associated binary evolutionary models for the first time. We were also able to shed light on the highly debated Be stars with gamma-Cas-like X-rays, with evidence mounting that they have mass-accreting WD companions. The new interferometric data also enable studying the effects that close binarity has on the structure of the Be star disks, such as the presence of circumcompanion gas and circumbinary structures.

Lambda Cold Dark Matter (LCDM) is the most successful theory for the formation of structure in the Universe. Although its predictions have been verified on large scales, they are still contested on the scale of dwarf galaxies, whose dynamical properties are often cited as evidence for the need to revise some of LCDM’s basic tenets. In this context, I will discuss the recent discovery of the faintest galaxies known to date, and how their properties may be used to place constraints on the clustering of dark matter on the smallest galactic and sub-galactic scales, as well as on the viability of some of the proposed alternatives to LCDM.

Present-day galaxies still contain a multitude of clues about their formation histories. But how do we best connect their current properties to their past?
As one of the rarest kinematic classes, prolate rotator galaxies hold a unique set of properties that help us constrain their origins.
Using cosmological simulations, I will show what insights about the formation and merger history of prolate rotators can be gained from a diverse set of
measurements that complement the observations. For this, I will present what we can learn from structures in the outskirts, the inner kinematics, and the
overall galaxy shapes of prolate rotators, building up a coherent picture of the formation of these galaxies.

Streamers, infalling gaseous structures ranging from a few hundred to over 10,000 astronomical units, have been identified as a new method of supplying material to protostellar and protoplanetary disks. However, their prevalence and role within the broader context of star and planet formation remain uncertain. The occurrence of streamers around protostars is still debated, with only a few dozen identified to date, and even fewer with measured infall properties, leaving gaps in our statistical understanding of their significance. In this presentation, I will show the results of the first systematic search for streamers in a star forming region. Leveraging combined data from NOEMA and IRAM 30m, we identified streamer candidates around 7 out of 16 protostars and pre-main sequence stars in the southeastern portion of NGC 1333. These streamers are likely composed of material originating outside the natal filaments, suggesting an external source of infall. Our findings indicate that streamers may be a common feature, particularly during the embedded phases of star formation. I will finally discuss the impact that streamers can have in the development of protostars and their future planets.

High-redshift galaxy protoclusters serve as nurseries for young, rapidly growing star-forming galaxies that eventually quench and become the backbone of massive clusters at lower redshifts. During the cosmic noon, these large-scale structures are fed by vigorous cold gas streams fueling the star formation activities of their members. The Spiderweb protocluster is a well-known protocluster at z=2.2 which is expected to evolve into a massive cluster in a few Gyr. The unique compilation of data for this structure makes this field an ideal test-site for investigating the environmental effects on galaxy evolution. I will explore several scenarios that influence the growth and quenching of galaxies within the Spiderweb protocluster by analyzing molecular gas content and star formation rates. 

The element compositions of resolved stars formed at distinct epochs record the chemical evolution trajectory of a galaxy. As this evolution is influenced by the galaxy-wide stellar initial mass function (gwIMF), the abundance profiles of stars offer a means to estimate the gwIMF. In this presentation, I will demonstrate the application of this methodology using the dwarf galaxy Sculptor as a case study. Specifically, I will elucidate how the gwIMF of long-lived low-mass stars intricately shapes the observed stellar metallicity distribution of a galaxy, thereby allowing for the estimation of low-mass gwIMF via galaxy chemical evolution modeling. Our analysis suggests that dwarf galaxies, characterized by low stellar metallicities and a low star formation rates, exhibits a shallower gwIMF slope for low-mass stars and a steeper gwIMF slope for massive stars (bottom- and top-light IMF). Furthermore, we have compared our findings with those derived from independent IMF estimation techniques including stellar population synthesis and star counting, illustrating a coherent and systematic IMF variation.

The intermediate-mass black hole (IMBH) regime is still poorly constrained, with few detections between 150 and 10^5 Msun. This poses a challenge to our understanding of supermassive black hole formation in the early universe.
An IMBH in ω Centauri, the Milky Way’s most massive globular cluster, has been suspected for almost two decades, but all previous detections have been questioned due to their assumptions and the possible mass contribution of a central cluster of stellar mass black holes.
I will present a new astrometric catalog for the inner region of ω Centauri, containing 1.4 million proper motion measurements based on 20 years of Hubble Space Telescope observations.
Our catalog is supplemented with precise HST photometry in 7 filters, allowing the separation of its complex subpopulations. The catalog is publicly available, providing the largest kinematic dataset for any star cluster.
Our new catalog revealed 7 fast-moving stars in the innermost 3 arcseconds (0.08 pc) of ω Centauri. The inferred velocities of these stars are significantly higher than the expected central escape velocity of the star cluster, so their presence can only be explained by being bound to an IMBH. From the velocities, we can infer a firm lower limit of the black hole mass of ∼8,200 Msun. In addition, we compare the full distribution of stellar velocities to N-Body models that suggest the presence of an IMBH with M≲50,000 Msun. These results confirm ω Centauri hosts an IMBH which makes this the nearest known massive black hole and, after the Milky Way center, only the second where we can track the orbits of multiple individual bound companions.

The advent of high-resolution, near-infrared instruments such as VLT/SPHERE and Gemini/GPI has helped uncover a wealth of substructure in planet-forming disks, including large, prominent spiral arms in MWC 758, SAO 206462, and V1247 Ori among others. In the classical theory of disk-planet interaction, these arms are consistent with Lindblad-resonance driving by multi-Jupiter-mass companions. Despite improving detection limits, evidence for such massive bodies in connection with spiral substructure has been inconclusive. In search of an alternative explanation, we use the PLUTO code to run 3D hydrodynamical simulations with two comparatively low planet masses (Saturn-mass, Jupiter-mass) and two thermodynamic prescriptions (three-temperature radiation hydrodynamics, and the more traditional beta-cooling) in a low-mass disk. In the radiative cases, an m = 2 mode, potentially attributable to the interaction of stellar radiation with gap-edge asymmetries, creates an azimuthal pressure gradient, which in turn gives rise to strong spiral arms. Monte Carlo radiative transfer (MCRT) post-processing with RADMC3D reveals that in near-infrared scattered light, these spirals are significantly more prominent than the Lindblad spirals generated by the planets. Our results demonstrate that even intermediate-mass protoplanets---less detectable, but more ubiquitous, than super-Jupiters---are capable of indirectly inducing large-scale spiral disk features, and underscore the importance of including radiation physics in efforts to reproduce observations.

Our Galactic thick disk is distinct from the dominant thin disk through its unique stellar chemistry and age. However, there is no consensus on how the thin and thick disks formed and evolved, and the answer is unlikely to come from studying our Milky Way alone. Specifically, the degree to which radial mixing varies from one galaxy to another, as well as the role of star-formation-driven outflows, remains very poorly constrained. In this talk, I will present the GECKOS survey, an ESO VLT/MUSE large program of 35-edge on galaxies that aims to reveal the variation in key physical processes of disk formation. Edge-on galaxies are ideal for this task as they allow us to disentangle the assembly history imprinted in thick disks and provide the greatest insights into gas outflows. I will present the survey’s first results based on 2D measurements of stellar abundance, age, and kinematics, as well as ionised gas metallicities, ionisation parameters, and outflow kinematics — all core ingredients for chemical evolution models. In particular, I will focus on a galaxy with a newly discovered counter-rotating thick disk that may provide new insights into the long-standing question of the merger origin of the thick and thin disks. I will present a comprehensive picture of the counter-rotating galaxy’s assembly history. The most likely formation scenario is that the distinct disks resulted from a gas-rich major merger, which formed a new dominant thin disk. This theory is closely connected to one of the leading formation scenarios for our Galaxy’s thick and thin disks.

Galaxy clusters are the largest gravitationally bound structures in the Universe. Numerical simulations provide detailed scenarios on how they assemble and evolve over the lifetime of the Universe, but observational evidence supporting these predictions is still elusive. Galaxy populations in nearby clusters are dominated by dwarf stellar systems, and the number of these galaxies continues to grow over time even at the present epoch. In this talk, I will present the results of the observational campaign conducted over the last 5 years, including the analysis of deep long-slit spectroscopic datasets for over 250 dwarf early-type galaxies, including around 50 ultra-diffuse galaxies, in three massive nearby clusters: Coma (D=99 Mpc), Abell 2147 (D=165 Mpc), and Abell 168 (D=193 Mpc), as well as spectra of dwarf galaxies in the Virgo cluster (D=16.5 Mpc), publicly available in the Keck, Gemini, and VLT data archives, that have also been reduced and analyzed. These spectroscopic datasets were complemented by re-reduced archival deep optical images from Subaru HSC and CFHT MegaCam instruments, using a dedicated sky background modeling technique that allows for accurate background subtraction. For every galaxy we obtained a spatially resolved optical spectrum reaching up to 1-2 half-light radii from its center, which was used to determine internal properties such as stellar kinematics, ages, and chemical composition of their stars, and to perform Jeans dynamical modeling, which yields dark matter content and dynamical masses. Profiles of radial velocity for a dozen of dEs in the Coma cluster demonstrate a large fraction of kinematically decoupled cores, suggestive of relatively recent mergers. These results point to several scenarios of dE galaxy formation and evolution and correlate them with different dE sub-classes, like UDGs. This dataset allows us to directly test the applicability of the abundance matching to galaxies in clusters in the 3x108–5x109 M☉ range in stellar mass.Link: https://teams.microsoft.com/l/meetup-join/19%3ameeting_YmI1OWE1ZDAtMjY1MC00MWJjLWEyNGU[…]2c%22Oid%22%3a%22a23844ec-b897-4c71-bbb6-b3b16dde2ae2%22%7d

In this talk, I will present the experiments we are conducting at the User Support Department (USD) to create a chatGPT-based chatbot to support ESO users. We are using the new OpenAI tool called “GPT”, which allowed us to create a custom version of ChatGPT focused on supporting users of ESO instruments and on helping users with the ESO phase 1 and phase 2 processes.  The current version uses as context public manuals for all the VLT instruments, and a few La Silla instruments, as well as some official public ESO webpages. This GPT is still in the development and testing phase and, thus, is not publicly available yet.

However, to help us test the tool, we encourage any interested ESO student/fellow/staff member to sign up to become a beta tester.

Using the IllustrisTNG and TNG-Cluster simulations, I quantify the impact of satellite galaxies on the host halo gas as functions of satellite stellar mass, host halo mass, and cosmic time. Before infall, satellite galaxies were still central galaxies with their own multiphase CGM and ISM, undergoing feedback from star-formation and/or SMBHs. As they fall into other larger hosts, ranging from MW-like galaxies to the largest clusters in the Universe, both their CGM and ISM are redistributed due to both internal feedback processes and external environmental effects, such as ram pressure stripping. Namely, satellites deposit their own gaseous reservoirs into the host halos, contributing to both the cool and hot gas in their host CGM. In particular, I follow the evolution of ~500 jellyfish galaxies in TNG50 as they deposit their cool, metal-enriched ISM into their host halos. Meanwhile, some massive cluster satellites in TNG-Cluster are able to retain their own CGM, contributing to the overall soft X-ray flux in the intracluster medium (ICM). Further, I show that the ICM today is multiphase, where clusters tend to have ~10^9-10 Msun of cool gas in their halos, according to TNG-Cluster. In the past, however, these ~350 cluster progenitors had ~10^10.5-11 Msun of cold gas, which yields observable predictions. The evolution of the cool ICM since z <~ 4, which holds for lower mass halos as well, is a complex interplay between new cool gas sources and sinks, including accretion from large scale filaments, satellite stripping, gas cooling, and gas heating via AGN feedback and virial shocks. Lastly, I discuss in-situ ICM star-formation and potential Halpha emission therefrom, and compare the MgII column density profiles in TNG-Cluster to recent SDSS stacks, where TNG-Cluster naturally produces a signficant amount of MgII absorbers.

In this talk, I will discuss some seemingly unrelated results from different observations of protoplanetary disks. I will mostly focus on our work modelling the SED of disks using an artificial neural network and what we learned by applying this to sources in Taurus. I will then describe our surprising findings when studying the nearby protoplanetary disk MP Mus with ALMA, one of the closest young solar analogues which remained relatively unexplored until recently. Finally, I will propose an alternative (and simpler) explanation for some of the disk azimuthal asymmetries that ALMA has revealed, which can help us better understand their vertical structure. Put together, these observations tell a story that suggests a solution to one of the current main issues in planet formation – only one that we may not like.

The next two decades will see an exciting wave of increasingly capable exoplanet missions, new instruments, and exoplanet surveys. In this talk, I will present Bioverse, a comprehensive exoplanet survey simulation and hypothesis testing framework. Bioverse is capable of assessing the scientific diagnostic power of exoplanet surveys and informs mission and survey trade studies. I will demonstrate its functionality for transiting and direct imaging surveys from ground-based telescopes (GMT, ELT, LFAST) and space-based missions (PLATO, HWO, Nautilus, LIFE). I will explore what questions can be answered and show how surveys can be designed to test hypotheses about the atmospheric evolution of habitable worlds, the existence of the habitable zone, and discontinuities in the exoplanet population.

One of the great challenges of exoplanetary astrophysics is to understand how the observed properties of exoplanets – their masses, orbital characteristics, bulk properties and atmospheric compositions – are connected to planet formation in their host protoplanetary disks. Recent observations of water and other molecules in both young protoplanetary disks as well the atmospheres of evolved exoplanets by JWST, shed new light on this fundamental question.   The evidence indicates that the composition of planets cannot be understood as a consequence of their formation at one place in the disk. It is well known that planet-disk interaction leads to planetary migration - and this means that forming planets will accrete pebbles, planetesimals, and gas with a wide range of chemical compositions as they move through their evolving disks.  In this talk, I will summarize these latest observational and theoretical advances and argue that these point towards the emergence of a new paradigm for planet formation. One essential process that controls disk chemistry, evolution, and planetary migration is how angular momentum is transported in disks. Recent theoretical work favours disk winds (observed as ubiquitous jets and outflows in protostellar systems) as carrying it away from disks, rather than disk turbulence carrying it outward to large disk radii (observations indicate that disk turbulence is hard to detect, or absent). I will discuss our own recent contributions to disk wind driven evolution and its effects on planet formation by confronting our theoretical planetary populations with the observations.

The Systems engineering department (DIS) of the Institute of research into the fundamental laws of the Universe (IRFU), at CEA Paris-Saclay, is in charge of designing, integrating and commissioning the instruments requested by IRFU’s scientific projects. DIS is specialized in the fields of mechanical and thermal engineering, instrumentation, control systems and equipment design at the system level. Leveraging its complementary expertise, DIS engages from feasibility studies up to the deployment phase, including the industrialization follow-up. DIS contributes to instrument testing, platforms maintenance and evolution via technological infrastructures. It engages actively in R&D activities in order to keep state-of-the-art engineering toolboxes.

In the field of astrophysics, DIS contributes to the mechanical and thermal engineering of space instruments, but also telescopes or ground-based instruments. It also develops instrumental test equipment (cryostat tests or cryogenic optical benches) and associated control systems necessary for the qualification of different models or some detection components such as the cryogenic, low power and high-performance repositioning engines (“cryomechanisms”) for infrared instruments on ground or on-board.

DIS started to work in collaboration with the ESO in the frame of VISIR project, from the late 1990s. After more than 20 years, we’ve developed some specific knowledge in the field of cryomechanisms for astrophysics applications that have naturally led us to contribute to EUCLID space mission, and more recently to the METIS collaboration in view of the ELT. We will be glad to share with you the story of our cryomechanisms, their performances and the associated AIT facilities. We will keep time for discussions about potential interest of this technology for other ESO instruments.

Herbig-Haro jets provide a fossil record of the accretion activity of their driving sources. In compact multiple systems this accretion can be regulated by the chaotic motion of the stars. I will give a broad overview of the dynamical processes that lead to the formation of parsec scale jets with particular reference to a new detailed study of perhaps the finest known jet complex, HH 24, based on Subaru, ALMA, HST, and JWST data.  

Quasars – active super-massive black holes at the center of galaxies – are the brightest non-transient sources in the Universe and are powered by intense accretion episodes. The copious radiation emitted by a luminous quasar can, like a flashlight, illuminate the surrounding material, allowing us to directly study structures extending to circumgalactic (~100 kpc) and intergalactic (Mpc) scales. In this talk I will quickly report on some of the latest results of the QSOMUSEUM survey which comprises, at the moment, VLT/MUSE observations for 120 z~3 single quasar fields and 8 quasar pairs. Using high-resolution cosmological simulations I will then discuss the importance of quasar outflows and radiation in explaining the emission we see on circumgalactic scales, and show how the observation of extended emission around quasars not only give us access to the gas properties, but also to the properties of the central engine itself (black-hole mass, accretion rate, ionization cone opening angle).

I will also discuss the importance of high dispersion spectroscopy in the Extremely Large Telescopes (> 30 m) era, focusing on the ANDES instrument at the European ELT, both in terms of refining our understanding of gas giants and pushing towards colder, smaller planets.

While galaxies stand out as the brightest lights observed by telescopes, most of the atoms in the Universe are in diffuse gas outside of galaxies. The circumgalactic medium, or CGM, refers to the massive gas halos surrounding galaxies. In addition to containing large quantities of matter, the CGM is where some of the main processes driving and regulating galaxy formation operate. This talk will begin with a broad introduction to the CGM, then focus on recent results from our group concerning a key phase transition in the CGM, known as "virialization," during which the CGM transforms from cold to hot. I will discuss theoretical predictions, based on a combination of analytic modeling and simulations, for how the CGM virializes. I will also summarize results on the connections between CGM virialization and the evolution of galaxies, including the transition from bursty to steady star formation and the emergence of disk galaxies similar to the Milky Way. The predicted bursty phase of star formation enhances the abundance of bright galaxies and, in our simulations, plays a critical role in explaining the luminosity function measured by the James Webb Space Telescope at very high redshift.

The distribution of galaxies in the universe is inhomogeneous, representing large-scale structures (LSS) that consist of galaxy clusters, groups, and the filaments that connect them. Understanding how galaxy characteristics are influenced by their environments and how they evolve over cosmic time within LSS is crucial. Utilizing narrow-band selected emitters, we investigate the environmental effects on star formation within large-scale structures. Utilizing a novel double narrow-band technique, we also explore star-forming activity and the spatial distribution of Hα and continuum emission at z=0.4, probing the cosmic web. We found that star formation in cluster core galaxies is more centrally concentrated and reduced compared to the field sample. We also explore the morphological features and star formation activities of [OII] emitters in the COSMOS UltraDeep field at z ∼ 1.5 using JWST NIRCam data from the COSMOS-Web survey and Subaru Hyper Suprime-Cam. Furthermore, we report the discovery of large filamentary structures traced by [OII] emitters, surrounding an extremely overdense core with a galaxy number density ∼ 11× higher than the field average. Heightened star-forming activity was observed in dense regions, contrary to z=0.4, suggesting an environmental impact on early galaxy evolution. Additionally, we examine the redshift evolution of star-forming activities and morphology. Future studies will explore into the chemical abundance, gas content, and kinematics to comprehend the underlying processes.

Wide-area, sensitive X-ray surveys map the hot and energetic Universe to reveal key processes across many areas of astrophysics and Cosmology, including the most massive collapsed structures of the Universe
(clusters and groups of galaxies), the hot ISM and CGM of the Milky Way and the 
Supernova remnants that energise it, the atmospheres of neutron stars, 
the magnetic coronae of accretion discs around black holes, and many more.
eROSITA (extended ROentgen Survey with an Imaging Telescope Array), the 
soft X-ray instrument on the Russian-German Spektrum-Roentgen-Gamma 
(SRG) mission  is expanding the horizon of 
X-ray astronomy and delivering large legacy samples thanks to its high sensitivity, large field of view, high
spatial resolution and survey efficiency. I will present an overview of the instrument capabilities, the current status of the mission, and a few early science results from the survey program selected from the first data release.

Stars of mass below that of the Sun live for sufficiently long that even in ancient systems, star-count techniques can be used to investigate the low-mass stellar Initial Mass Function (IMF). The stars in Ultra-faint dwarf (UFD) satellite galaxies in the Local Group are extremely old and extremely metal-poor and likely formed long ago in an environment very different from that of the local solar neighbourhood.  The inferred dark-matter fraction in these systems is also significantly higher than the values found in larger galaxies. Comparisons between the low-mass IMF in UFD galaxies and that of the local Milky Way thus provides insight into star-formation processes across a range of conditions and redshifts. 

I will describe our recent analyses of deep images from the Hubble Space Telescope for a set of four UFD satellites of the Milky Way plus one UFD that is likely to be a satellite of the LMC.  We conclude that there is little evidence in favour of a variable low-mass IMF. 

I will explain the basis of simulation-based inference (SBI), a novel technique based on deep learning for robust Bayesian analysis. Afterwards, I will show how SBI can be applied to the domain of galaxy clustering to obtain cosmological parameters.

Systems where two gravitationally bound masses (the primary mass and its binary companion) interact with the surrounding gas and dust are extremely common in the Universe and involve a wide variety of different astrophysical objects (star + star, black hole + black hole, star + planet, or planet + moon). Extensive theoretical and numerical work from the late 1970s revealed that the material in the surroundings of binaries forms a disc structure around the binary, called “circumbinary disc”, and/or two circum-individual discs around the individual objects. The perturbative effects from the companion produce a variety of features in such discs, including spirals and other non-axisymmetric overdensities, dust/gas cavities, velocity kinks in the kinematics and the evolution of the disc eccentricity. 

The great advancements in observational capabilities during the past decade allowed us, for the first time, to observe such features in protostellar discs, triggering extensive work aimed at interpreting the data. 

In this talk, after a general overview of binary-disc interaction theory, I will review the ongoing efforts to model the morphology and kinematics of protostellar discs when companions (planet or stellar binaries) are present, and highlight some open issues that still require to be addressed. In particular, I will focus on the possibility that so-called transition discs, i.e., protostellar discs with dust and gas depleted cavities, are actually circumbinary discs where the binary remains unseen. In this respect, I will discuss our most recent results and the strategy to investigate this issue I am carrying on in the project ORBIT-D (Observing Binaries in Transition Discs). Finally, I will conclude by discussing future prospects remarking why, more generally, investigating the interaction of binaries with the star forming environment represents a fundamental step for fully understanding the process of star and planet formation.

The Atacama Large Millimeter Array (ALMA) is an extraordinary achievement of the partnership of the European Southern Observatory, the National Science Foundation in the USA, and the National Institute for Natural Sciences in Japan. ALMA comprises 66 antennas, each with 10 receiver systems operating between 32- 950 GHz, that can be reconfigured with baselines spanning 150m to 16km on the alti-plano of the Atacama desert at 5000m altitude. The collecting area and sensitive receivers, combined with its reconfigurability and the unique location, confer unprecedented performance capabilities at these frequencies. This talk will give a brief outline of ALMA’s capabilities, highlight some of the ground-breaking science from the first decade of operations, with an update on the current operational status.  The talk will conclude by describing the Wide-band Sensitivity Upgrade of the ALMA 2030 Roadmap that aims to expand ALMA’s scientific capabilities – by up to factors ~70x in some cases –  and touch on the challenge of alternative “greener” power considerations for ALMA in the longer term.

The 20-th century has seen the discovery of two fundamental theories, the general relativity and the quantum theory. Both have been confirmed in many ways during the past 100 years, but any attempt for a unification has failed so far. It is believed that any of such theories will require a minimal length scale provided by the Planck length λ ≈ 10^{-33} cm. Gravitational quantum mechanics (GQM) is a deformation of standard quantum mechanics (SQM) with a build-in minimal length scale λ > 0. Purpose of this informal discussion is to elaborate on some of the basic ideas of GQM and present a few recent elementary results.

The gaseous atmospheres of extrasolar planets and those of their birth environments, the protoplanetary discs, hold the key to understanding the observed diversity of these distant worlds and might provide important insights on fundamental questions, including habitability. 

In this talk I will review the results of recent efforts to connect the protoplanetary disc evolution, driven by their central star, to the formation of planets. Special attention will be given to outflows and what can be/ has been learnt from them. Some of the unanswered questions, rely on the understanding of the chemical composition of atmospheric gas, particularly with regards to important species like polycyclic aromatic hydrocarbons, that control the thermodynamics in the far ultra-violet regime and play an important role in the coupling of the atmospheric gas to magnetic fields. The same molecules may play a very important role in the evolution of planetary atmospheres. Current and future efforts to constrain their abundances in discs and planets will also be reviewed.

What determines stellar masses and the mass spectrum of stars?  Most stars form in short-lived, ultra-dense clusters from the gravitational collapse  and fragmentation of Giant Molecular Clouds.  I will argue that a `Ladder’ of ever-more potent feedback mechanisms, combined with the N-body dynamics of such clusters and unstable multiple star systems limits the efficiency of star formation,  sets stellar masses, and drives the cycling of atoms between the ISM and stars.   A ~100 Myr cycle-time with star formation efficiency of (SFE) ~5 to 10% implies an ISM consumption time-scale of 1 to 2 Gyr in the absence of infall from outside the Galaxy.

The Central Molecular Zone (CMZ) is an extreme environment in the inner few hundred parsecs of the Milky Way Galaxy, with temperatures, pressures, and densities exceeding those measured in the Galactic disk. At a distance of ~8.2 kpc, it has previously been difficult to perform large surveys of the CMZ at high resolution, limiting most studies to individual molecular clouds. ACES (the ALMA CMZ Exploration Survey) is a large ALMA program with high sensitivity observations covering the entire area of the CMZ at high spatial and spectral resolution at 3mm in both continuum and spectral lines. ACES data will be used to determine the overall distribution and chemical composition of mass in the inner Galaxy, from the sub-parsec scales of star formation, to the large-scale global processes that influence it. In addition, spectral line data will be used to create a comprehensive picture of gas kinematics in the CMZ, unveiling how gas flows from galactocentric radii of a few hundred pc down to the vicinity of the central supermassive black hole. Observations and high resolution hydrodynamical simulations will be used in tandem to determine how different physical processes impact the evolution of gas at different scales. We present early science results from the ACES team, including an overview of the data products, the properties of compact sources extracted using ACES continuum data, the rich chemical composition identified in the CMZ, and the characterization of gas kinematics in the CMZ. 

Warm Jupiters represent an intriguing class of exoplanets that offer unique insights into the limitations of current atmospheric study methods. The cross-correlation technique, a widely used method for studying hot, close-in planets, relies on the large orbital velocities of these planets to separate their spectra from that of their host stars. However, the atmospheres of warm Jupiters are challenging to study due to their predominantly molecular composition, including water, methane, and carbon monoxide, often obscured by clouds and hazes.

In our recent work, we investigated the atmospheres of six warm Jupiters using the ESPRESSO spectrograph and simulated observations for the upcoming ANDES spectrograph at the Extremely Large Telescope. Our results highlight the importance of system architectures, such as orbital eccentricity and argument of periastron, in maintaining the efficacy of the cross-correlation technique for accessing these atmospheres.

In this talk, I will discuss our findings and their implications of system architectures on atmospheric studies of this kind of planets, emphasising the need for careful selection and characterisation of planets to maximise the potential of the cross-correlation technique with ANDES.

CERN, one of the oldest European intergovernmental organisations, celebrates its 70th anniversary in 2024. The foundational CERN Convention was finalized in the summer of 1953, setting out the contributions of its Member States and its dedication to the dissemination of research results, international peaceful collaboration, and the education of future scientists. The discussion will centre on the integration of scientific research and education within an international context, emphasising the crucial role of international partnerships in enriching science education. A key focal point will be CERN's Science Gateway, a pioneering educational project designed to make science accessible to a diverse audience. We will also delve into the implications of artificial intelligence in science education, exploring both its potential to transform traditional learning environments and its integration into cutting-edge scientific research. Through examples of successful collaborations and innovative educational initiatives, I will demonstrate how merging research with education can cultivate a globally informed, scientifically adept society, equipped to tackle the complexities of the future.

On a continent far, far away, there is a telescope hidden two kilometers below the surface in the Antarctic ice at the South Pole. This telescope detects one of the most elusive messengers in astronomy: Neutrinos. In this discussion, I will present the working principles of neutrino astronomy, what main challenges we face, and some fundamental differences between neutrino astronomy and "classical" astronomy.  

Astrophysical black holes grow by accretion and mergers and therefore receive angular momentum. They are surrounded by a plasma-filled corotating region of spacetime, the ergosphere.Gravito-magnetic and ultrarelativistic collisional processes in the ergosphere give rise to a plethora of phenomena which can be studied using the methods of multi-messenger astroparticle physics and numerical simulations.  Considerable progress has been achieved in the understanding of the formation of Poynting-flux driven jets converting the rotational energy of the black holes into relativistic particles and magnetic fields. Next-generation instruments will allow to establish a coherent picture of the role of black holes in the non-thermal Universe.

Begrüßung

Prof. Dr. Reinhard Kienberger, Technische Universität München

Wolfgang Kaiser und die TUM

Präsident Prof. Dr. Thomas Hofmann, Technische Universität München

Wolfgang Kaisers Bedeutung für das (junge) Physik-Department

Dekan Prof. Dr. Johannes V. Barth, TUM School of Natural Sciences

Wolfgang Kaiser’s scientific achievements

Prof. Dr. Wolfgang Zinth, Ludwig-Maximilians-Universität München

Development of Ultrafast Science

Prof. Dr. Erich P. Ippen, Massachusetts Institute of Technology, USA

Globular clusters (GC) generally harbour variable stars of different types, with the RR Lyrae (RRL)  the most common. Other types are semi-regular giants and the blue-stragglers SX Phe stars. For decades it has been known that RRL are good distance indicators. Their light curve morphology however is sensitive to other physical parameters of astrophysical relevance, e.g. the metallicity, mass, radius and temperature. Fourier decomposition of their light curves leads to useful semiempirical relations which in turn can be used to estimate the mean metallicity and distance to the parental cluster. At some point (~2008) we became curious about using the RRL population in as many GC as possible to see if we could photometrically establish homogeneous scales for the mean iron abundance and distances. In this talk I will briefly describe our approaches to the understanding of the GC horizontal branch structure, and the photometric metallicity and distance scales.

Ultra-diffuse galaxies (UDGs) are extremely low-surface brightness galaxies with a size of several kpc, i.e. comparable to that of the Milky Way, but with at least 100 times smaller stellar masses. In the scope of the LEWIS large programme with VLT-MUSE, we have targeted a complete sample of 32 UDG candidates in the 50-Mpc distant Hydra I cluster. In this talk, I will focus on UDG 32, a galaxy that has been hypothesised to have formed from material stripped from the nearby spiral galaxy NGC 3314a. Our new MUSE data show that NGC 3314a's filaments extend to unprecedented distances, completely engulfing the UDG and confirm that the UDG and the filaments are indeed co-spatial based in position-velocity space. UDG 32 may thus be one of the first ultra-diffuse galaxies where we catch the formation from ram-pressure stripped gas in the act.

The gas emission from planet-forming disks can be used as a tracer of temperature, kinematics, and density, as well as constraining the physical processes driving the disk evolution. However, due to our imaging techniques, these studies are mostly limited to bright and extended sources.  In this talk, I show the potential of studying the gas emission directly in the visibility plane. Among the potential science cases for visibility-based techniques, I will demonstrate applications in a barely resolved compact disk, a cold and moderately resolved disk around a very low mass star, and isolating circumplanetary disk gas emission (Results from Kurtovic & Pinilla 2024).

I will present recent simulation results on AI-based AO reconstructors and time-resolved wavefront sensing, as well as experimental results obtained with REVOLT, the AO test-bench we have on our local 1.2m telescope, including fiber injection of AO corrected light and open-loop AO.

Driven by gravity, galaxies continuously grow through accretion of smaller systems. Stellar streams are nice illustrations of this hierarchical build-up, but the accreted stars quickly disperse. I will present advanced dynamical models that can convert the observed positions and velocities of stars to phase-space quantities like energy and angular momentum which remain largely conserved. In addition, these models can include the observed ages and chemical properties of stars which are also conserved. The resulting population-dynamical models allow us then to uncover even those accretion events which are now fully dispersed. At the same time, these models also accurately constrain the total mass distribution, including a central black hole and dark matter halo.

I will illustrate how these models make optimally use of observations to unveil the dark side and colour past of galaxies: from accurate measurements of their central black holes and extended dark halos, to unveiling the formation history of their disks, to uncovering ancient massive mergers and accreted satellite galaxies. By the end, I aim to have demonstrated that these models provide a unique bridge between the studies of resolved stars in the Milky Way and integrated-light of high(er)-redshift galaxies. Together with direct coupling to state-of-the-art galaxy formation simulations, these population-dynamical models enable us to uncover the hierarchical build-up of galaxies in a cosmological context.

The Next Generation Fornax Survey (NGFS) is a deep, panchromatic imaging campaign that covers the virial sphere of the Fornax galaxy cluster in the optical (u’g’i’, using DECam@CTIO) and near-infrared filters (JKs, using VIRCam@VISTA). The survey targets all baryonic structures down to point-source luminosities typical of globular clusters and reaches surface brightness limits deep enough to detect ultra-diffuse and LSB dwarf galaxies. I will present some interesting galaxy scaling relations and showcase our most recent findings related to the dynamical properties of satellite galaxies within the Fornax galaxy cluster. We identified a distinct transition radius, demarcating two zones where satellites exhibit varying properties of tidal stress. Intriguingly, this substructure mirrors patterns observed in other nearby environments and in cosmological galaxy simulations. If time allows, I will highlight exciting new results based on the H-alpha extension of NGFS.

High resolution, hydrodynamic galaxy simulations can be used to investigate the inherent variation of dark matter around the Solar Circle of a Milky Way-type galaxy. These simulations self consistently include both the baryonic back-reaction as well as assembly history of substructures, all of which may have lasting impacts on the dark matter’s spatial and velocity distributions, creating `gusts’ of dark matter wind around the Solar Circle, potentially complicating interpretations of direct detection experiments on Earth. Direct detection is a key experimental goal to advance the microscopic understanding of the dark matter that fills the Universe. We investigate how dark matter substructure, simulated in halos analogous to our own Milky Way, impacts the shape, summary statistics, and interpretation of results from terrestrial dark matter direct detectors.

Implementing a new numerical integration technique, our work generates bespoke predictions for terrestrial underground detection, finding large uncertainties arising in the expected signals of direct detection experiments. Having developed a realistic end-to-end pipeline for studying these effects, we discuss the implications of these astrophysical variations in the dark matter distribution of the solar neighbourhood on current and future particle physics searches for dark matter.

The abundance of massive halos (and of the galaxy clusters they host) has long been recognized as an extremely promising probe of the large-scale structure of the universe. Over the past decade, tremendous progress was made, notably thanks to the availability of high-resolution surveys of the Cosmic Microwave Background (CMB), of high-quality measurements of gravitational lensing, and of advanced numerical simulations.

The sample of galaxy clusters selected by the South Pole Telescope (SPT) in the CMB now exceeds a thousand objects. The Dark Energy Survey (DES) allows for measurements of gravitational lensing for almost 700 sample clusters with exquisit control over systematic uncertainties. We supplement this dataset with 39 lensing measurements of high-redshift clusters with the Hubble Space Telescope (HST). The joint analysis of the cluster abundance and weak-lensing mass calibration provides tight cosmological constraints that are competitive with other major probes.

In my talk, I will review the SPT cluster cosmology and mass calibration program. I will focus on the latest SPT + DES Y3 + HST analysis and present new cosmological constraints.

It is creativity/novelty that drives scientific breakthroughs and societal progress, but the journey from a novel scientific idea to a practical solution can be long and winding. Debates also persist regarding whether and how science contributes to practical solutions. In his talk, Jian will explore the complex relationship between novelty and impact in science and technological innovation. Furthermore, he will examine concerns that the current science funding system is increasingly risk-averse and favours short-term, safe projects over long-term, risky and novel projects. He will also present empirical evidence about whether major funding agencies are biased against novelty in their project selection process, and whether receiving funding enables grantees to engage more in novel research. Finally, he will discuss strategies that scientists can use to boost creativity, such as how to structure the professor-PhD student relationship, collaboration teams, and broader collaboration networks.

You can find the abstract and a short bio by the speaker at:

https://indico.euro-fusion.org/event/2559/page/18-highlight-topic-creativity-in-science

Wolf-Rayet stars (WRs) are the penultimate evolutionary stage for stars more massive than 25-40 Msun, and are considered immediate progenitors of stellar mass black holes. The formation of WRs through single or binary stellar evolution channel is a debated topic, and the contribution of the two channels is uncertain. To get more insights into this, spectroscopic studies have attempted to determine the multiplicity of WRs, but are largely limited to relatively high mass ratios and short periods. In this talk, I will discuss a complementary approach to this problem with infrared interferometry and highlight the key discoveries and limitations of this method.

On their way from the main sequence to the final supernova explosion, massive stars lose a substantial fraction of their mass through line-driven winds. Recent decades have witnessed significant advancements in both observational and theoretical studies of these winds that sail on starlight. The advancements in our understanding of radiative driving lead to progressively more accurate estimates of mass-loss rates from massive stars. In this talk, we will outline the key ingredients necessary for reliable predictions of mass-loss rates from numerical simulations, and demonstrate how state-of-the-art theoretical mass-loss rate estimates compare with observational results.

In recent years, thousands of exoplanets have been discovered. These are a diverse set of planets that range from rocky and Earth-like to giant gaseous planets much larger than Jupiter. Of these, only a handful have been observed while still embedded in the disks from which they form. This is because directly observing forming planets is difficult. Not only are these objects faint and close to their young stellar host, but also the disk emission complicates many of the traditional techniques for separating the various bright components in order to isolate the planetary signal. In this talk, I will discuss the use of infrared aperture masking interferometry with VLT/SPHERE and JWST to observe the cavities of transition disks at separations beyond the capabilities of traditional direct imaging methods. I will discuss the use of a joint Bayesian modelling approach to fit for the dominant disk emission and simultaneously recover any point-like planet signal. I will discuss the results of applying this approach to ground-based data of LkCa 15 and HD 100546, as well as the first space-based interferometric detection of exoplanets, PDS 70 b and c.

FAIR Open Data is one of the pillars of modern research. It is the paradigm whereby data ultimately become available and findable without restrictions, independently of the circumstances of their acquisition, thus sparking the generation of more science results and allowing the scrutiny of previous claims. Virtually all of today's facilities are equipped for Open Data, and practically all current funding schemes require it in some form.

ESO has a long tradition in Open Data, having run a science archive since the late 1980s. In this Informal Discussion, we will review the theory, practice, perils and impact of Open Data, using the ESO Science Archive, and beyond, as guidance.

Thanks to the recent deep observations, some massive galaxies are known to stop their star formation even just 1-2 Gyrs from the Big Bang. These early massive quiescent galaxies are likely to have obtained their stellar mass by bursty star formation within a short period and suddenly got quenched. However, their statistical properties and quenching mechanisms are still unclear. In this talk, I will introduce our recent studies to characterize massive quiescent galaxies using data from ground-based and space telescopes. 

In the first part of this talk, I will present the result of characterizing the morphology of quiescent galaxies at z>3 using the high-resolution imaging of JWST/NIRCam. We derived their sizes and Sérsic index of ~30 quiescent galaxies. For the first time, we have shown that the size is larger for more massive quiescent galaxies at z>3, as seen at z<3. Their typical sizes are ~0.6kpc at Mstar~5x10^10Msun, smaller than that at z<3; thus, significant size evolution occurred for quiescent galaxies over the last 10 Gyrs.

In the second part of this talk, I will present our study investigating the connection between quenching and AGNs at z~3-5. Using the Chandra data and the multi-band photometry of the ground-based telescopes, we conduct the stacking analysis of X-ray images of ~500 quiescent galaxies. For the first time, we detected the average X-ray emission of quiescent galaxies at z~3-5 and found that they typically have low-luminosity AGNs. Their X-ray luminosity is higher than that of star-forming galaxies, suggesting the possible connection between AGNs and quenching. Also, I will introduce our ongoing work on the detailed characterization of X-ray-detected quiescent galaxies at z~2.

The main DESI redshift surveys have now collected 3 years of data and analysis of the Year-1 data set is almost complete. While concentrating  on the analysis of the Bright Galaxy Survey (BGS) in which I'm most directly involved  I plan to review the main cosmological results from other components of DESI. The BGS is a magnitude-limited (r<19.5) galaxy redshift survey and so rather like the SDSS main survey but about two magnitudes deeper. As such it is not only a useful cosmological probe but also a powerful probe of the local galaxy population and so a constraint on galaxy formation and the galaxy dark matter connection. I will present an analysis of how galaxy clustering depends on galaxy properties and the galaxy luminosity function depends on environment.

The enigmatic journey of massive black holes, from the formation of a seed population in the early universe to their subsequent growth and mergers represents a vastly multi-scale phenomenon deeply intertwined with the process of galaxy formation. In this talk, I discuss the insights gleaned from cutting-edge cosmological simulations. These simulations not only provide some clues into the elusive population of Intermediate Mass Black Holes (IMBHs) but also shed light on some of the largest black holes in our Universe.

The stars evolving through the asymptotic giant branch (AGB) are generally regarded as highly efficient dust manufactures, owing to the thermodynamic properties of their wind, which prove extremely favourable to the condensation process of gas molecules into solid grains. In this review I will describe the dust and mineralogy of the dust  formed in the surroundings of this class of stars, outlining the role of mass and metallicity, and the importance of these studies for the characterization of evolved stellar populations in galaxies. The contribution from the analysis of the spectral energy distribution of post-AGB stars towards a better understanding of the dust formation process by AGB stars will be also commented on.

ALMA observations of Betelgeuse in 2023 reached a resolution of ~8 milliarcsec – the highest to date. The continuum results show long-lived hotspots on the surface, and a photosphere of this supergiant which is clearly not spherical. In molecular lines, clumpy emission and absorption can be imaged from just above the photosphere. Comparing the results with data taken ~9 years previously suggests that these structures are rather long-lived – not what has been predicted from some theoretical models.

Two new lines from Rydberg transitions of Hydrogen and heavier elements were discovered, and I describe how these transitions can be used to study the atmosphere of this star.

At bands 9 and 10, ALMA can potentially reach 4-5mas resolution, and I describe what science could be possible with this – the highest resolution observations of stellar photospheres possible until ELT and ngVLA are built.

After decades of being mostly confined to the local Universe, the study of gas dynamics in galaxies, via a variety of emission-line gas tracers, has now become a key tool of investigation across cosmic time. The rotation of the gas allows us to trace the distribution of matter, quantify the mass and shape of the dark matter halos and study galaxy scaling relations. At the same time, gas turbulence reveals the effects of stellar feedback and disc instabilities and provides clues on the formation of the stellar thin/thick discs. I will present results on high-z rotation curves and velocity dispersions obtained through 3D reconstruction techniques of the emission-line datacubes. I will focus on ALMA observations of galaxies at z~4-5 observed in [CII] emission lines, extending to intermediate redshifts (z=1-4) using mostly CO lines. These data reveal fast rotation and relatively-low gas velocity dispersions leading to typical V/sigma values of order 10, similar to those of nearby spiral galaxies. Often, the fast rotations show the presence of mass concentrations that suggest a quick formation of stellar bulges, while the low velocity dispersions indicate that the gas turbulence is mostly fed by supernova feedback. I will discuss how the widespread presence of such “cold” discs at z~4-5 and their properties are changing our understanding of galaxy formation at early times.

With its unique combination of enormous light gathering power and unprecedented spatial resolution (thanks to state-of-the-art adaptive optics), the ELT is set to revolutionise observational astrophysics.  HARMONI – the ELT’s integral field spectrograph - will provide spatially resolved spectroscopy of a wide variety of astronomical sources, ranging from solar system objects to the most distant galaxies ever observed.  Extremely sensitive medium resolution spectroscopy will open new ways of understanding the physical processes throughout the history of the Universe. By using line strengths and ratios, together with Doppler shifts, HARMONI observations can deduce the morphology of the kinematics, chemical composition, and physical characteristics (density, temperature, etc.) at high angular resolution.  The talk will showcase some of the salient observations where HARMONI@ELT can have a huge impact, together with work on simulations that will tie the observations with detailed physical understanding of the evolution of galaxies over cosmic time.

Ground-based resolved imagery of asteroids has seen a remarkable growth over the past decade, essentially due to the availability of high-order correction adaptive optics systems like Sphere at the VLT. Such observations transitioned from supporting in-situ space missions to establishing themselves as stand-alone science programs aiming at searching for the presence of asteroid moons and informing us about minor bodies geology, collisional history, and surface and internal composition.
In this talk, I’ll briefly review the progress made over the past decades, focusing on recent precise determination of asteroids shape and density, and how this information helps us constrain the core-surface compositional gradient of these bodies and how they collisionally and dynamically evolved since their formation. 

I'll introduce a new class of radio objects, the Odd Radio Circle (ORCs). You'll learn why they're odd; how far away they are; and some ideas for what may produce them, based on recent optical spectroscopy.

I will present recent results from the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM), a high resolution survey of molecular gas in galaxy nuclei. First, I will show that CO can be used to easily and accurately measure the masses of the supermassive black holes (SMBHs) lurking at galaxy centres. In particular, I will highlight the latest measurements, that spatially resolve the SMBHs’ spheres of influence with a few tens of resolution elements, thus leading to very precise measurements. Second, I will introduce SMBH mass-independent metrics to compare molecular gas and megamaser measurements. In turn, I will show that molecular gas observations now probe the same region of the SMBHs’ neighbourhoods, and that the mass measurements are now equally competitive. Third, if time allows, I will introduce the newly-discovered "mm fundamental plane of black hole accretion", that is surprisingly tight and holds for a wide variety of active galactic nuclei and stellar-mass black holes. This work opens the way to both precise and numerous SMBH mass measurements across the Hubble sequence (in both active and non-active galaxies) with a unique method, and thus promises to revolutionise our understanding of the co-evolution of galaxies and black holes.

The frequency of gas giants versus their mass and orbital separation, as a function of host mass, provides a powerful test of planet formation theory.  With a large database of point estimates of planetary mass companion occurrence rates, covering orbital separations 0.3 to 300 AU, and masses 0.3 to 30 Jupiter masses, we combine data from surveys of M dwarfs, FGK, and A stars, to search for global trends.  To accurately assess the planet population, it is vital that very low mass brown dwarf companions are considered as a separate population.  We also search for dependence of critical planet parameters on host star mass.  We have used this model to interpret direct imaging surveys and identify a local maximum in the gas giant planet orbital distribution.  Here we present an update which fits the gas giant planet populations of M, FGK, and A stars as a log-normal orbital distribution with a peak between 3-6 AU (68 % confidence interval) and recovers the power-law mass function (dN/dq ~ q-1.3) consistent with many other studies.  We compare our results to predictions of planet formation theory.  Finally we discuss our model in the context of new Y dwarf surveys with JWST, recent discoveries around high mass stars in Sco Cen, as well as characterization spectra of wide-orbit companions. 

The Poisson-Boltzmann theory stems from the pioneering works of Debye and Onsager and is considered even today as the benchmark of ionic solutions and electrified interfaces. It has been instrumental during the last century in predicting charge distributions and interactions between charged surfaces, membranes, electrodes, macromolecules, and colloids. The electrostatic model of charged fluids, on which the Poisson-Boltzmann description rests and its statistical mechanical consequences have been scrutinized in great detail. Much less, however, is understood about its probable shortcomings when dealing with various aspects of real physical, chemical, and biological systems. After reviewing the Poisson-Boltzmann theory, I will discuss several extensions and modifications to the seminal works of Debye and Onsager as applied to ions and macromolecules in confined geometries. These novel ideas include the effect of dipolar solvent molecules, finite size of ions, ionic specificity, surface tension, and conductivity of concentrated ionic solutions.

Near-infrared interferometry is a unique tool to study the inner sub-parsec structure of AGN which is inaccessible with current single dish telescopes. With VLTI/GRAVITY, we can now spatially resolve not just the hot dust continuum on milliarcsecond scales through imaging but also the broad-line region on microarcsecond scales through spectro-astrometry. In this talk, I will review the latest results from our observations of local AGN with GRAVITY where we have mapped the kinematics of the BLR in seven nearby AGN, measured sizes of the hot dust for sixteen AGN, and reconstructed images for two AGN. BLR kinematics have allowed us to independently measure the BLR size and supermassive black hole mass where we begin to find a departure from the radius-luminosity relation at high luminosity. I will give an overview of the GRAVITY+ upgrades that will allow for direct black hole mass measurements out to high redshift and therefore a precise tracing of supermassive black hole-galaxy coevolution through cosmic time.  With the addition of wide-angle off-axis fringe tracking during the first phase of GRAVITY+, we have already pushed observations out to cosmic noon. I will show initial results from this program, including the first dynamical black hole mass measurement at high redshift which reveals an undermassive black hole that is accreting at super-Eddington rates.

The study of high-z clusters and protoclusters is fundamental to understanding the connection between the evolution of galaxies and their environment. Theoretical models of galaxy formation and evolution are still challenged by observations of a highly diverse star formation scenario in (proto)clusters at z~2, confirming that the physics of galaxy formation is not well understood yet. This cosmic time is characterized by the transition from highly star-forming protoclusters to mature clusters, and its study is a fundamental step in constraining our knowledge of galaxy evolution. Cosmological hydrodynamical simulations are currently among the most advanced tools to investigate this. I will present the analysis of a set of state-of-the-art high-resolution cosmological hydrodynamical simulations of galaxy (proto)clusters and compare them with an average cosmological volume, acting as a "control field", to isolate the effects of environment on galaxy populations. Monte Carlo radiation transfer of stellar light through a modeled dust distribution was included in post-processing in order to enable a proper comparison with the observed properties of (proto)cluster galaxies. I will show how the simulations succeed in reproducing some observables related to the star formation and dynamics of galaxy populations, while others remain a challenge, leaving questions open on which key ingredients are still lacking in our theoretical framework.

The Young Suns Exoplanet Survey (YSES) is a direct imaging search for young self-luminous gas giant exoplanets around one Solar mass stars in Sco-Sen. I will talk about our discoveries of three exoplanet systems found so far from our intial sample of 72 stars, the latest results that we have in the analysis of these planets with separations of 100 to 700 au, and discuss the possible formation and evolution scenarios. I will also introduce our follow up survey extending our sample to another 150 young one solar mass stars, called the Wide Sepration Planets in Time (WiSPIT) survey where we propose to test formation mechanisms for these planets by looking at detection rates as a function of time from 1 Myr to 15 Myr.

In 2021 a young, solar type star underwent a complex series of eclipsing events that lasted over 900 days, preceeded by an infrared brightening seen in NEOWISE photometry some 1000 days prior to the optical eclipse. We propose that this is evidence for a collision event between an ice giant exoplanets and another exoplanet in the system, forming a luminous remnant called a `synestia’ surrounded by an expanding and cooling cloud of debris that caused the later optical eclipse. We show that Cycle 3 JWST spectroscopy will be able to confirm our models for the glowing remnant and surrounding cooler dust cloud, and discuss the implications for planet formation and evolution.

Giant radio galaxies (GRGs) are radio galaxies (RGs) with a projected extent larger than 700 kpc and they play a crucial role in shaping our understanding of the evolution and dynamics of radio galaxies (RGs). In this presentation, I review the lifecycle of RGs, focusing on the distinct properties of GRGs. I present a multi-wavelength study of approximately 1600 RGs, including 280 GRGs, identified in the Low Frequency Array (LOFAR) deep fields. I discuss differences in host galaxy properties, environment, and evolutionary stages between GRGs and smaller RGs.

The analysis reveals insights into the interplay between jet power and host galaxy mass, shedding light on the mechanisms driving the formation and evolution of GRGs. Additionally, I explore environmental properties using the number of neighboring galaxies within 10 Mpc as a proxy, uncovering distinctive environmental properties of GRGs compared to smaller RGs (< 700 kpc). Integrated flux densities and radio luminosities were also determined for a subset of RGs through available survey images at 50, 150, 610, and 1400 MHz to compute integrated spectral indices. The findings of this analysis demonstrate that GRGs not only represent the largest RGs in the universe but also serve as key indicators of the advanced stages of RG evolution.

Accretion disks are common in astrophysical systems, from AGN to protostellar disks. The disks of Be stars (rapidly rotating Main Sequence B-type stars) are special: they are discretion disks, built from matter ejected by the central object. When in a binary system, the companion can affect the Be disk in many ways, exciting density waves and even causing truncation. It can also accrete material from it, as is the case for Be X-ray binaries, whose X-ray emission is powered by accretion onto a compact companion. In our work we simulate Be binaries with a smoothed particle hydrodynamics (SPH) code (Okazaki et al. 2002) in order to investigate the effects of the companion on the dynamics of the disk, the process through which it accretes matter, and how the system loses mass as whole. We employ a modified version of the code, specially updated by us to increase resolution in low density areas of the system, such as the outer disk and around the companion. We find that disks are formed around the secondary in all models, but viscosity, mass ratio and period play a significant role in their structure and kinematics. A circumbinary disk is formed around the system for all simulations, which was never before seen in simulations for coplanar, circular Be binaries, but agrees with recent observational findings of radio emission from these types of system, where an ad-hoc circumbinary disk model was employed. Our study paves the way for a better understanding of X-ray emission in Be X-ray binaries, and offers an insight in how hidden companions of Be stars can be detected observationally.

The Northern Light has been inspiring awe in humans for millennia. We mostly see three colors of light dancing in the sky: Blue aurorae at 428 nm coming from excited N2, Green aurorae at 557.7 from atomic oxygen, and red aurorae mainly at 630 nm also due to atomic oxygen. Interest in the polarization of the northern light started in 1959, but the reported measurements were quickly disputed and the results were deemed unreliable. Interest in this topic has been low, until 2008, when they again observed the red line of the Aurora and found a significant signal. However, this and the following polarization measurements of the other lines lacked spatial information. In this talk, I will present measurements of the polarization of the Aurora with our new compact instrument which can do RGB linear polarization measurements. I will discuss the main obstacles we faced, solutions such as adding an additional halfwave plate, and a preliminary view of the latest results.

Supernova remnants (SNRs) drive large-scale shocks that locally enhance the density of the surrounding material but also inject vast amounts of energy and momentum that largely perturb and disperse the Interstellar Medium (ISM). The interplay between these two effects is considered paramount in regulating the star formation efficiency in galaxies. However, how SNRs affect the physical conditions of the ISM is not well constrained from an observational point of view. In this talk, I will present our work aimed to address this question. I will show our study of the large scale shock triggered by the SNR W44 on the molecular cloud G034. I will show how the shock, probed by Silicon Monoxide (SiO) and observed with ALMA, enhances the density of the processed gas to values compatible with those required for massive star formation and has helped to shape the cloud. I will also present our exploratory large single-dish observing program SHREC, aimed to observe the molecular shock tracer SiO(2-1) toward a sample of 30 SNRs known to be interacting with molecular clouds. I will introduce the aim and technical aspects of SHREC and present the first results obtained toward the SNRs IC443. IC443 is a well known SNR, expanding into and interacting with a nearby toroidal molecular cloud. Toward the major site of interaction, known as clump G, we estimate the mass of the shocked gas to be 100 Msun. The shock driven by IC443 into this material enhances its density by a factor >10, to value consistent with those required to ignite star formation. Finally, we estimate up to 40% of the momentum injected by IC443 is transferred to the nearby molecular material. Our work therefore indicates that the molecular ISM is an important carrier of the SNR momentum and that the SNR-molecular cloud interaction play a crucial role in the regulating star formation in galaxies.

Stellar-mass black holes (BHs) are unique objects to constrain stellar and star cluster initial conditions and evolution, as they encode valuable information on their short-lived progenitor stars. If a significant fraction of BHs receive negligible natal kicks at birth, they can be retained even in open clusters with low escape velocities.

In this talk, I will present the first search for BHs in the closest open cluster to the Sun, the Hyades. I will show that the exquisite measurements by Gaia, combined with accurate N-body models, now give us the opportunity to infer signatures of even few BHs in open clusters, from the imprints they leave on the cluster’s stellar populations. For the Hyades, the observations are best reproduced by models with 2-3 BHs at present, while those that have never possessed BHs cannot match the cluster mass and size simultaneously. I will discuss how this result can provide key information on the BH natal kick distribution, one of the most crucial but still unconstrained aspects of BH formation.

Moreover, I will characterize the populations of BH-star binaries in open clusters. I will explore possible candidate stars with a BH companion in the Hyades, based on their excess error in the Gaia single-source catalog but high membership probability. Finally, I will investigate if dynamical interactions in young and open clusters can trigger the formation of Gaia BHs.

The birth of stars and the formation of galaxies are cornerstones of modern astrophysics. While much is known about how galaxies globally and their stars individually form and evolve, one fundamental property that affects both remains elusive. This is problematic because this key property, the birth mass distribution of stars, referred to as the stellar initial mass function, is a key tracer of the physics of star formation that underpins almost all of the unknowns in galaxy and stellar evolution. It is perhaps the greatest source of systematic uncertainty in star and galaxy evolution. The past two decades have seen a growing variety of methods for measuring or inferring the initial mass function. This range of approaches and evolving definitions of the quantity being measured has in turn led to conflicting conclusions regarding whether or not the initial mass function is universal. Here I review this growing wealth of approaches, and highlight the importance of considering potential initial mass function variations, reinforcing the need to carefully quantify the scope and uncertainties of measurements. I present a new framework to aid the discussion of the initial mass function and promote clarity in the further development of this fundamental field.

Future and ongoing infrared and radio observatories such as JWST, METIS, and ALMA will increase the amount of rest-frame IR spectroscopic data for galaxies by several orders of magnitude. While studies of the chemical composition of the interstellar medium (ISM) based on optical observations have been widely spread over decades for star-forming galaxies (SFGs) and, more recently, for active galactic nuclei (AGN), similar studies need to be performed using IR data. In the case of AGN, this regime can be especially useful given that it is less affected by temperature and dust extinction, traces higher ionic species, and can also provide robust estimations of the chemical abundance ratio N/O. Moreover, regarding (Ultra)-Luminous Infrared Galaxies ([U]LIRGs), the IR regime peers through their dusty medium and allow us to include the obscured metals in their studies. In this contribution, I will provide a summary of the bayesian-like code HII-CHI-Mistry-IR, which takes advantage of photoionization models, characterized by the chemical abundance ratios O/H and N/O, and the ionization parameter U, to compare their predicted emission-line fluxes with a set of observed values. Instead of matching single emission lines, the code uses some specific emission-line ratios that are sensitive to the above free parameters. I will also review our most recent findings from the study of IR emissions, starting from the performance of the code and its comparison to optical studies, following by a discussion on the universality of the S/O chemical abundance ratio, which can be independently estimate thanks to the set of emission lines available in this regime, and ending up by the finding of deviations from the mass-metallicity relation (MZR) as a consequence of the action of massive inflows of metal poor gas that produces that some galaxies experience a "deep-diving" phase in the MZR diagram as the metals from their ISM are diluted. 

A third of all massive stars are predicted to lose their hydrogen-rich envelope through mass transfer or common envelope ejection initiated by a binary companion star. As a result, the hot and compact helium core is exposed. These "stripped stars" are the direct progenitors of hydrogen-poor supernovae and merging binary neutron stars, but they are also so hot that they should boost the ionizing output from bursty star-forming galaxies.

Despite their importance, stripped stars remained, until recently, observationally unconfirmed since their predicted existence over half a century ago. We found the first set of stripped stars by combining ultraviolet and optical photometry with follow-up spectroscopy in the Magellanic Clouds. By fitting their spectra with a new grid of models, we could measure stellar properties and thus confirm that the predictions from binary evolution models are broadly consistent with observed stripped stars.

This discovery is a step towards understanding the role of interacting binaries in stellar populations. This is evidenced, for example, by the highly ionized gas surrounding some of these systems, shining brightly in O III and Balmer spectral lines. Directly constraining the ionizing emission and hardness of stripped stars, along with the typical gas density surrounding the stars, could lead to estimates of the escape fraction for different star types and the disentangling of stellar populations in unresolved galaxies.

I will present one of the most recent climate simulation results regarding the potential collapse of one of Earth’s most prominent tipping elements: the abrupt collapse of the Atlantic meridional overturning circulation (AMOC). AMOC is a system of ocean currents that brings warm water north and cold water south in the Atlantic. Its potential collapse could lead to abrupt cooling of the Northern Hemisphere, changes in tropical rainfall patterns, and non-linear changes in sea-level rise in the North Atlantic. Using the Community Earth System Model, Van Westen et al. (2024) simulated the first AMOC tipping event due to ocean freshwater forcing from Greenland Ice Sheet melt. From their results, they developed a physics-based and observable early warning signal of AMOC tipping. Atmospheric reanalysis products indicate that the present-day AMOC is on route to tipping, but current time series measurements do not allow us to predict when this abrupt transition might occur. Abrupt transitions occurring due to climate change might have a dramatical impact on ecosystems and living organisms on our planet.

Van Westen et al., Sci. Adv., 10, 6, 2024

Circumstellar disk dispersal is a brief, yet critical, end stage of disk evolution, dictating the end of planet formation and migration. Thermal winds powered by high-energy stellar photons have long been theorized to drive disk dispersal. However, evidence for these winds is currently based only on small (~3-6 km/s) blue-shifts in [Ne II] 12.81 um lines, which does not exclude MHD winds. We report JWST MIRI MRS spectro-imaging of T Cha, a disk with a large dust gap (~20 au in radius) and known blue-shifted [Ne II] emission. We detect four forbidden noble gas lines, [Ar II], [Ar III], [Ne II], and [Ne III], of which [Ar III] is the first detection in any protoplanetary disk. After performing continuum and PSF subtraction, we discover a spatial extension in the [Ne II] emission off the disk continuum emission, consistent with a disk wind. In contrast, we also find compact [Ar II] emission.

We then show how by applying photoionization radiation transfer to simple hydrodynamic wind models we can predict the extent and luminosity of the Ne and Ar line emissions. Along with the low degree of ionization implied by the line ratios, we find that the relative compactness of [Ar II] compared to [Ne II] implies a dense wind such that soft X-rays and EUV only reach the inner parts of the wind while harder X-rays ionize the wind to larger radii. This requires high mass-loss rates (~10^-8 Msun/yr) and small wind launch radii (~1 au), that are consistent with the properties of X-ray-driven photoevaporation.

These high mass-loss rates suggest that we may be witnessing the last stage in T Cha’s disk evolution, which is supported by the serendipitous discovery of a significant change in the continuum consistent with a depletion in the mass of the inner disk.

HARPS is one of the most long-lived and proficient instruments installed at ESO telescopes. During 20 years of operation, it has produced about 800 thousand spectra, half of them of astrophysical sources and the other half of the Sun. These observations have been of paramount importance in advancing the understanding of stellar phenomena and discovery of exoplanets.

A first critical review of the observations of astrophysical sources was published in the ESO Archive as HARPS Radial Velocity catalog. This allows archive users to access the radial velocity of the targets and identify the spectral types observed, expanding the RV content using the Halpha line for RV determination.

In this talk, I will discuss the process of associating these observations with SIMBAD identifiers, a key step in cataloging and analyzing this vast dataset, and I will show how the resulting HR diagram from the HARPS RV catalog facilitates the identification of stars based on their physical characteristics.

I will also present the plan for producing a high-resolution high signal-to-noise stellar library and offer some insights into the chemical/physical and temporal characterization of this dataset.

This past summer, the pulsar timing array community announced strong evidence for the presence of a stochastic background of nanoHertz frequency gravitational waves. This has been the primary goal of the community for the past two decades, and it took thousands of hours of telescope time, over 500,000 pulse arrival times from ~70 millisecond pulsars, and a highly sophisticated and very computationally demanding analysis effort to accomplish. While we can't yet say for certain what is causing the gravitational waves, our best guess is a population of slowly merging super-massive black hole binaries throughout the universe. But it is possible that the signal also heralds new physics. So what does it all mean and what are we expecting next? And what other cool things can we do with all of this high-precision pulsar data?

Paper: https://arxiv.org/pdf/2304.01757.pdf

The chemical evolution of distant galaxies, unlike nearby galaxies, cannot be assessed from observations of individual stars. On the other hand, the study of the interstellar medium (ISM) is an alternative way to reveal important properties of the chemical evolution of distant galaxies. The outcome of the evolutionary history of galaxies is recorded in the interstellar abundances of the chemical elements. Observations of the interstellar medium (ISM) in galaxies of various types, which differ in mass, size, metallicity, and are at different evolutionary stages, can provide a key to understanding the processes taking place in galaxies.I will present the study of the abundance patterns of the neutral ISM in 110 gas-rich mostly-metal-poor distant galaxies (Damped Lyman-alpha absorbers, DLAs) at redshifts 0.60 < z < 3.40. We observe systematic deviations from the basic abundance patterns for O, Mg, Si, S, Ti, and Mn, which we interpret as alpha-element enhancements and Mn underabundance.  We constrain for the first time the distribution of the alpha-element enhancement with metallicity in the neutral ISM in distant galaxies. Less massive galaxies show an alpha-element knee at lower metallicities than more massive galaxies. If this collective behaviour can be interpreted as for individual systems, this would suggest that more massive and metal-rich systems evolve to higher metallicities before the contribution of SN-Ia to [alpha/Fe] levels out that of core-collapse SNe, possibly explained by different SFR in galaxies of different masses. Overall, our results add important clues to the study of chemical evolution of distant galaxies.

The activity of the Sun and solar-like stars is driven by a dynamo mechanism, according to which the combination of differential rotation and convective motions of the outer atmospheric envelope continuously regenerates the magnetic field that manifests itself in the form of powerful optical, UV, and X-ray radiation. M-L dwarfs are also known to be magnetically active, but the physical mechanism is poorly understood. Studying their X-ray emission and its variability with rotation and stellar parameters allows to constrain the dynamo mechanism that powers the magnetic field and causes activity in the atmosphere.

In this talk, I present our attempt on constraining the magnetic dynamo of M dwarfs by studying the mass-dependent activity-rotation relation for the largest and most uniform sample of M dwarfs with observations taken with XMM-Newton, Chandra, eROSITA, K2 and TESS combined with X-ray and rotation data from the literature. Finally, I will present the relation between the X-ray and radio luminosity of ultracool dwarfs, and the evidences of a previously proposed bimodal dynamo responsible for the magnetic activity of these objects.

Found to be among the most dark matter-dominated systems discovered to date, low-mass galaxies provide stringent tests of our cold dark matter model on small scales. Because they are intrinsically faint and difficult to identify and characterize, studies thus far have primarily focused on the population of dwarf galaxies orbiting the Milky Way. I will present novel observations of low-mass galaxies beyond our local galactic neighbourhood, uncovering their considerable diverseness and introducing new astrophysical puzzles. I will describe a new framework for obtaining constraints on the distribution of dark matter in low-mass galaxies by leveraging their globular cluster systems and dynamical considerations. I will also present new constraints on the statistical mapping between satellite galaxies and their host dark matter halos, utilizing a unique sample of satellite galaxies in the Local Volume from the ELVES survey. I will conclude by discussing ongoing and future surveys essential in mapping the census and properties of the general population of low-mass galaxies.

Pressure broadening is one of the general line broadening processes in astrophysics. Indeed, it is widely used to model spectra from stelar and exoplanetary atmospheres, where the gas pressure is significantly high. However, its effect has been ignored in the field of planet formation. In this talk, we show that pressure broadening can affect line emission with high optical depths, even under a typical condition of the inner ~10 au region of protoplanetary disks, which produces very broad line wings. By taking advantage of this phenomenon, we can directly measure the gas pressure and density, which is otherwise a very difficult task. Indeed, we found that the CO molecular line spectrum from the nearest protoplanetary disk around the young star TW Hya has a very broad line wing, which is characteristic of pressure broadening. We successfully derived the gas density profile and found that the disk is gas-rich and a promising site for planet formation.

The magnetic field is one of the critical segments of the interstellar medium. It has been proposed that supporting interstellar clouds against gravitational collapse by magnetic fields could explain the low observed star formation efficiency in the Milky Way and other galaxies. Planck satellite provided a 5-15' all-sky map of the magnetic field geometry in the diffuse interstellar medium. However, higher spatial resolution observations are required to understand the transition from diffuse gas to gravitationally unstable gas. The Flame Nebula, also known as NGC 2024, is located in the Orion B molecular cloud and provides an excellent opportunity to study the role of the magnetic field in the formation, evolution, and collapse of filaments, as well as the dynamics and effects of young HII regions on the surrounding molecular gas. NGC 2024 contains a young, expanding HII region and a dense filament that harbors embedded protostellar objects. In this talk, I will present the results of our recent work on analyzing the magnetic fields in the Flame Nebula. We use new SOFIA HAWC+ 154 and 216 micron dust polarization measurements and the CN and HCO+ emission as part of the IRAM 30-m ORION B large program. In this work, we determine the geometry of the magnetic field and estimate the strength of its plane of the sky component across the NGC 2024. The magnetic field in NGC 2024 follows the morphology of the expanding HII region and the direction of the main filament. The derived plane of the sky magnetic field strength is moderate, ranging from 30 to 80 micro G, with the strongest measured at the east edge of the HII region, whereas the weakest field is found toward the filament in NGC 2024. We have found that the magnetic field has a non-negligible influence on the gas stability at the edges of the expanding HII shell and the filament, a site of the current star formation.

The Large Hadron Collider (LHC) offers a unique opportunity to probe the dark matter sector by producing dark matter particles in high-energy proton-proton collisions. Although such particles are invisible to an LHC detector, once produced, they can reveal themselves through their interactions with the known particles of the Standard Model. The LHC has developed a comprehensive dark matter search program, covering various collision signatures, such as large missing energy, resonant signals from new mediator particles, or invisibly decaying Higgs bosons. More recently, experimental techniques have advanced to probe also extended or strongly-interacting dark sectors, that would result in unconventional long-lived or novel hadronic signatures. A review of recent collider dark matter searches, their interplay and interpretations will be presented.

Where and how stars form within galaxies are two of the most critical questions in galaxy evolution. Our understanding of the star formation process is limited, ultimately, by our understanding of the sites of individual star formation — giant molecular clouds (GMCs). These dense, gaseous structures have sizes of 10s of pc, so the high spatial resolution required to resolve them has been mostly unattainable beyond the Local Group before the advent of the ALMA interferometer. Even then, acquiring the statistical sample of these ‘cloud-scale’ observations to answer questions like how local environment (bars, rings, etc.) module the star formation process has been an undertaking requiring 100s of hours of observing time with dedicated teams.

I will present some new results from the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) project looking at the properties of molecular clouds in ‘red and dead’ early-type galaxies, attempting to understand why these often molecular gas-rich galaxies do not form stars. We find that the molecular gas in these galaxies is often not in virial equlibrium, and external forces such as shear are likely destroying the clouds on shorter timescales than required for star formation to occur. The gas in these galaxies may be analogous to those in the Central Molecular Zone (CMZ) of the Milky Way, and provide an excellent laboratory for studying the interaction between extreme dynamics and cloud-scale properties. Combining ALMA with MUSE optical inteferometry, I have also been studying star formation on a resolved level in these quiescent galaxies. Star formation appears to be extremely localised to very small regions of the galaxy, and our integrated star formation rate measurements may be severely biased by this, with the true SFR being maybe an order of magnitude lower. However, resolved star formation efficiencies are similar to that of star forming galaxies, indicating that when star formation does happen, it perhaps happens in the same way across the galaxy population. 

I will give an introduction to the structure and dynamics of the central 3 kpc of the Milky Way. This region hosts a complex star-forming ecosystem that is continually exchanging matter with the rest of the Galaxy through inflows and outflows. The Galactic bar efficiently transports gas from the Galactic disc towards the centre at a rate of ~1 Msun/yr, creating a ring-like accumulation of molecular gas known as the Central Molecular Zone (CMZ) at a radius R=120pc. The CMZ is the local analog of the star-forming nuclear rings commonly found at the centre of external barred galaxies, and forms by a process similar to the one that creates gaps in Saturn’s rings. Once in the ring, approximately 10% of the gas is consumed by its intense star formation activity. Star formation does not occur uniformly throughout the CMZ ring, but is more likely to occur near the sites where the bar-driven inflow is deposited. The star formation rate of the CMZ varies as a function of time, but it is currently debated whether this is due to an internal feedback cycle or to external variations in the bar-driven inflow rate. The radius of the CMZ gas ring slowly grows over Gyr timescales, and its star formation activity builds up a flattened stellar system known as the nuclear stellar disc, which currently dominates the gravitational potential of the Milky Way at 30pc<R<300pc. Most of the gas not consumed by star formation in the CMZ is ejected perpendicularly to the plane by a Galactic outflow powered either by stellar feedback and/or AGN activity, while a tiny fraction continues moving radially inward towards the circum-nuclear disc at R=few pc, and eventually into the sphere of influence of the central black hole SgrA* at R<1pc.

• From 11:00 to 12:30
• From 13:45 to 15:00

Paper: https://arxiv.org/abs/2310.08052

An ESO internal ALMA development study, BRAIN is addressing the ill-posed inverse problem of image analysis employing astrostatistics and astroinformatics [1,2]. These emerging fields of research offer interdisciplinary approaches at the intersection of observational astronomy, statistics, algorithm development, and data science [3]. In this study, we provide evidence of the benefits in employing these approaches to ALMA image analysis for operational and scientific purposes. We show the potentials of two techniques (RESOLVE [4,5] and DeepFocus [6]), applied to ALMA calibrated science visibilities. Significant advantages are provided with the potential to improve the quality and completeness of the data products and overall processing time. Both approaches evidence the logical pathway to address the incoming revolution in data analysis dictated by ALMA2030 [7]. Moreover, we bring to the community additional products through a new package (ALMASim) to promote advancements in these fields, providing a refined ALMA simulator usable by a large community for training and/or testing new algorithms.

[1] Guglielmetti, F. et al. "Bayesian and Machine Learning Methods in the Big Data Era for Astronomical Imaging" Phys. Sci. Forum 2022, 5(1), 50; https://doi.org/10.3390/psf2022005050

[2] Guglielmetti, F. et al. ?A BRAIN Study to Tackle Image Analysis with Artificial Intelligence in the ALMA 2030 Era? Phys. Sci. Forum 2023, 9(1), 18; https://doi.org/10.3390/psf2023009018

[3] Siemiginovska, A. et al. "Astro2020 Science White Paper: The Next Decade of Astroinformatics and Astrostatistics", arXiv 2019, arXiv:1903.06796

[4] Junklewitz. H. et al. "RESOLVE: A new algorithm for aperture synthesis imaging of extended emission in radio astronomy", A&A, 586, A76 (2016)

[5] Tychoniec, L. et al. "Bayesian Statistics Approach to Imaging of Aperture Synthesis Data: RESOLVE Meets ALMA" Phys. Sci. Forum 2022, 5(1), 52; https://doi.org/10.3390/psf2022005052

[6] Delli Veneri, M. et al. "3D detection and characterization of ALMA sources through deep learning", 518, 3 (2023); https://doi.org/10.1093/mnras/stac3314

[7] Carpenter, J.; Iono, D.; Kemper, F.; Wootten, A. "The ALMA Development Program: Roadmap to 2030", arXiv 2020, arXiv:2001.11076

Recent discoveries of accreting brown dwarfs (BD) and exoplanets that appear to accrete at anomalously high rates have placed new importance on understanding the mechanisms that control their growth and formation. I will discuss my work to disentangle systematic effects from true physical variation in substellar accretion properties using the Comprehensive Archive of Substellar and Planetary Accretion Rates (CASPAR). CASPAR consists of >1000 measured Ṁs from ~800 T-Tauri stars, BDs, and planetary mass companions (PMC), making it the largest compiled sample of Ṁs for accreting objects to-date. I will show that systematically rederiving physical and accretion properties for all objects in the database has a negligible effect on the scatter in the M-Ṁ relation while showing that the remaining broad scatter is attributable to physical effects such as age, mass, and variability.

The DSA-2000 will be a world-leading radio survey telescope and multi-messenger discovery engine, commencing construction in 2025. Building on proven technology developed for DSA-110, the array will consist of 2000 x 5m dishes instantaneously covering the 0.7-2 GHz frequency range, spanning an area of 19 km x 15 km in Nevada. In an initial five-year survey, the DSA-2000 will image ~33,000 deg2 repeatedly over sixteen epochs, producing a combined full-Stokes sky map with 500 nJy/beam rms noise and 3.3 arcsecond spatial resolution. Fundamental questions surrounding the baryon cycle in galaxies, the formation of stars over cosmic time, and the influence of active SMBHs on galaxies, will be addressed by detecting over a billion star-forming galaxies and active SMBHs, and by observing the neutral-hydrogen kinematics and contents of several million galaxies. The array will revolutionize the field of radio transients, detecting >10,000 FRBs, >10,000 pulsars and >1 million slow transients, with sub-arcsecond localization for host galaxy identification. The DSA-2000 will also be a leading instrument for the discovery and characterization of the electromagnetic counterparts to neutron-star mergers found by ground-based GW detectors. Overall, it will thus also serve as the radio counterpart of the Rubin-LSST survey.

There has been a tremendous leap forward in our understanding of the formation of planetary systems thanks to substantial advances in our observational capabilities. Observatories like ALMA are routinely revealing the presence of complex structures in the gas and dust which are forming planets, much of which has been associated with young, embedded protoplanets. Such observations are unpinning sigificant developments in the theory of how, and from what, planets form. In this talk I will provide an overview of our current understanding of the physical, chemical and dynamical structure of protoplanetary disks with a particular focus on how we are beginning to detect the presence of young planets, only recently formed. I will present new results from the exoALMA program, an ALMA Large Program that is undertaking an extensive planet-hunting campaign in the sub-mm, and the related projects on facilities like JWST, VLT and Magellan. To conclude, I will discuss future facilitiies, and detail how, in the coming decade, we will begin to push into the terrestrail planet forming regions of these disks and understand the formation of Earth-like planets. 

Supervised learning methods are routinely used on tabular data of light-curves (either feature based or involving deep learning) to classify the origin of the variations. On the other hand, a not so commonly used approach is to classify the phased curves as "static" images themselves. We are not the first group to propose this approach but since it is still not commonly used I will present the main challenges and achievements we faced from a conceptual point of view. As this is meant to be an informal discussion, some intuitive principles will be explained regarding how our architecture works, how data have to be (and are) processed, etc

ALMA has embarked upon a 150 million Euro upgrade, the so-called “Wideband Sensitivity Upgrade” or WSU, that is currently planned to be commissioned and ready for use around the end of this decade. In this talk I will outline what this upgrade means both in practical terms and for new capabilities. This is a truly massive upgrade, with essentially only the ALMA antennas staying the same. All other parts of the signal chain  - receiver bands, digitizers, data transmission system, over 40 km of optical fibres, correlator – will be replaced or upgraded to give a system with x2 to x4 increase in instantaneous bandwidth. The WSU upgrade will result in a factor of 3-6 increase in continuum mapping speed and a factor of 2-3 increase in spectral line imaging speed. Importantly, ALMA users will no longer need to sacrifice bandwidth in order to work at high velocity resolution (e.g., 0.1 km/s). For ALMA operations, a major change will be that the ALMA correlators, which are currently at >5 km altitude, will be replaced by a correlator at the ALMA Base Camp (Operations Support Facility at 3 km altitude). To meet the challenges of this era of intensive ALMA Development, for ALMA 2030 and beyond, the ESO ALMA Support Centre (EASC) has recently created a new department for Development. In this talk I will describe the new EASC structure and other ways that the EASC is stepping up to the delivery of this - in essence - brand new ALMA.

Paper: https://arxiv.org/pdf/2307.03222.pdf

Gas is the dominant mass constituent of protoplanetary disks and its distribution and evolution have a profound impact on every major step of planet formation: planetesimal formation, accretion of planetary atmospheres, and migration of planets. Yet, we only have a limited understanding of how much gas a typical disk has, how the gas disk evolves and what mechanism(s) drives its global evolution.

In this talk I will show measurements of the gas disk size can be used to indirectly study the mechanisms that drive disk evolution and I will discuss what we learned from current observations.

I will also present some of first results of the ALMA Large Program AGE-PRO, which aims to trace the evolution of the gas throughout the lifetime of protoplanetary disks by quantifying gas masses and gas disk sizes for 30 disks across the whole range of disk lifetimes (0.1-10 Myr).  

Low-mass star-forming regions are blooming in emission from abundant complex organic molecules (carbon-containing molecules of at least 6 atoms). Unbiased spectral surveys and the advent of state-of-the-art interferometers like ALMA have tremendously expanded our understanding of the chemical composition of protostellar regions. The earliest stage of star formation, the prestellar core, is the birthplace of complex organic molecules under interstellar physical conditions. Upon gravitational collapse, a young protostar with a protoplanetary disk is formed. The concurrent heating and UV irradiation boost the production of complex organics. It is thought that the largest reservoir of complex organics is in interstellar ices, which can now be directly probed by the JWST. Meanwhile, thermal desorption in the warm inner regions around protostars allows us to readily observe such species in the gas with ALMA. In the outer parts of a protoplanetary disk, solid complex organics become integrated into forming comets and planets.

Our Solar System was once too an infant low-mass protostar embedded in its natal cloud. The most pristine relics of this time that survive to this day are comets. Recently, cometary science experienced a significant boost as a result of the large wealth of data coming from the ESA Rosetta mission that escorted comet 67P/Churyumov-Gerasimenko for two years. In my talk, I will highlight recent observational investigations of complex organics from cores to protostars, including studies of methanol isotopologs in the prestellar core L1544 and the comprehensive chemical inventory of the low-mass star-forming region IRAS 16293-2422. I will present the chemical trail that connects the earliest phases of star formation with comets in our Solar System. I will address the story told by the comet’s volatile inventory and isotopic ratios about the connections with protostellar and prestellar phases, thereby bring forward the idea that comets of our Solar System reflect to a degree the complex organic composition of the innate core that birthed our Sun.

MPE: Women in Astronomy (scientific talk, in English)

The Assembly, Integration and Verification of a system on an observatory is a critical part of the lifetime of a project. We explain the main steps needed for this activity based on experience gained on La Silla Paranal Observatory. It covers the preparation with the logistics, the safety , the procedures, the Interfaces, the team the AIV itself with the assembly in integration hall, transport to the telescope and integration on to the focus, but also few words about the verification on sky, the commissioning and the validation for operation.

The presentation is based on successful and less successful experiences, which hopefully gives an hint at the complexity of implementing such unique systems on a remote area.

I will present some of my experiences moving from engineering to Astronomy. Some of the advantages and disadvantages of this change and also some differences between the two fields I've seen along the way. It was a good idea? We will see...

The masses of the supermassive black holes in AGNs can be determined by resolving the BH sphere of influence in time via reverberation mapping (RM). The resulting relationship between the broad-line region (BLR) radius and AGN luminosity serves as a baseline for measuring black hole mass (MBH) across the entire Universe.  For an increasing number of nearby AGNs, time-costly high signal-to-noise and high cadence RM data provide insights into BLR geometry and kinematics, offering independent MBH measurements. In combination with spatially-resolved measurements of the host galaxy kinematics, this enables us to constrain the MBH-host galaxy scaling relations with unprecedented resolution. In this talk, I will present the calibration of the MBH-stellar-velocity-dispersion relation for a sample of AGNs with velocity-resolved lags from the BLR. I will discuss the biases introduced by different aperture sizes, host galaxy morphologies, and AGN luminosities, along with the consequences for interpreting such scaling relations as tests for the black hole - host galaxy co-evolution.

I will show observations of ALMA and JWST, along with radiative transfer models to analyse the physical and chemical conditions of protostellar systems which could be where planets start to form. From the observational side, I will use ALMA to quantify complex organic molecules (COMs) in the gas around young protostars, and show that their abundances are consistent with their formation under similar conditions, likely in ices of the prestellar phase. I will then show observations of JWST that (tentatively) detect two nitrogen-bearing COMs in interstellar ices for the first time. From the modeling side, I will use radiative transfer models to investigate how physical conditions such as source structure can change molecular emission and molecular abundances with emphasis on their implication for ALMA and JWST observations. Finally, I will use high angular resolution ALMA observations to further explore the predictions of radiative transfer models with a bonus of a disk wind detection in two new molecules.

Optically active confined spins in solids such as semiconductor quantum dots, colour centres in diamond and atomic-scale defects in 2D-semiconductors are of interest for a wide range of applications in quantum science and technology. In the context of photon-based quantum technologies electron and hole spins localized in single quantum dots can be used for the high rate (~100\,MHz) on-demand generation of single photons with excellent quantum indistinguishability. This talk will provide a snapshot of the recent progress and challenges for quantum light sources, spin-photon interfaces, optical interconnection of distant spins, as well as outlining recent progress in quantum state detection using superconducting nanowires. Finally, we will also explore how spin states in emerging 2D-semiconductors provide fascinating perspectives in quantum sensing and metrology.

We will reminisce about the what happened leading up to the discovery of the accelerated expansion and what it took to get there. Some of the consequences of this discovery will also be presented.

The SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars) project aims to perform a transit search on the nearest (< 40 pc) ultracool (<3000K) dwarf stars. The project is based on a network of 1m robotic telescopes, composed by the four ones of the SPECULOOS-Southern Observatory (SSO) in Cerro Paranal, Chile, one telescope of the SPECULOOS-Northern Observatory (SNO) in Tenerife, and the SAINTEx telescope in San Pedro Martir, Mexico. The prototype survey of the SPECULOOS project on the 60 cm TRAPPIST telescope (Chile) discovered the TRAPPIST-1 system, composed of seven temperate Earth-sized planets orbiting a nearby (12 pc) Jupiter-sized star. The project's main motivation is to discover potentially habitable planets well-suited for detailed atmospheric characterisation with James Webb Space Telescope (JWST) and the upcoming giant telescopes, like the European Large Telescope (ELT). Beside conducting observations of targets from the SPECULOOS input catalog, a fraction of the available observing time of the SPECULOOS network is used to carry out different science goals, the so-called annex programs. I will present an overview of the project, our observation strategy and the management and operations of our facilities. Finally, I will show the latest results of the survey and the synergy of our programs with the Transiting Exoplanet Survey Satellite (TESS) and JWST.

There are strong indications from physics at both infinitesimal and cosmic distances that our current understanding of the laws of nature is only approximate, and must be replaced by deeper principles. Both in particle physics and in cosmology, novel geometric structure have made an appearance that hint at underlying mathematical structure. Many of these insights are driven by theoretical studies of scattering amplitudes -- the basic building blocks used to predict outcomes of particle scattering. In this talk I will review recent progress in this fascinating field.

In our quest to find other Earths, we’ve uncovered an extraordinarily diverse set of outcomes of the star-planet formation process, far beyond our imagination, and yet we have still barely scratched the surface of what we can learn about this eclectic zoo of other worlds. While exoplanet hunters continue the search for the nearest Earth twins, our last decade of study has pushed to understand the atmospheres of these new planets, and how their climate physics and chemistry respond to the environment created by their parents stars. In this talk, I will demonstrate how new instrumentation, high in resolution, precision, and contrast is pushing our understanding of exoplanet atmospheres to increasing detail. I’ll discuss studies of gas giants as well as the crucial preparation we are doing to find biosignatures on nearby rocky worlds with the Extremely Large Telescopes. Finally, I will demonstrate our recent work on techniques to map out storms in giant exoplanet atmospheres, and end by discussing the next phase of exoplanet observations that aim to reveal the surface interactions of rocky exoplanets.

Orbyts is a multi-award-winning movement that partners scientists with schools to empower school students to undertake world-leading research. We aim to address diversity issues in science and to support short-supply science teachers who have extensive time pressures. We accomplish this through multi-term partnerships that are proven to transform science inclusivity, inspire school students and teachers, and ignite scientists' leadership potential. In this discussion I will explain how the Orbyts programme works on a practical level, and share some of the highlights of our most recent impact report.

Multiple populations distinguishable by their light-element content are well studied in many globular clusters (GCs). Additionally iron spreads have been measured in some of them. In this talk an analytical method to determine the number of core collapse supernovae (CCSNe) that must have contributed to this iron spread is presented. From this the duration of star formation during the initial stage of a GC’s development can be computed. For a sample of 55 GCs with known iron spreads we find that the number of CCSNe required to explain the iron spread varies between a few tens of thousands and a few. In most cases, however, this leads to a SF duration typically around 3.5 Myr.

There is a diverse chemical inventory in protostellar regions that has led to the classification of two extreme types of systems: hot cores, for the hot and dense systems that contain complex organic molecules, and warm carbon chain chemistry sources, for the warm and dense regions near a protostar containing unsaturated carbon chain molecules. Since these definitions were presented there has been a growing field to detect these sources and determine any co-existence between these classes of molecules. There have been few studies surveying these molecules in high mass star forming regions—places of significance as the birthplace of most stars. In this talk, I present spectral surveys in two high-mass star forming regions in Cygnus X—AFGL 2591 and IRAS 20126—with the Green Bank Telescope and the IRAM 30m Telescope. From the observed molecular spectra, I first determine the physical conditions of these regions, producing maps of the gas temperatures, column densities, and velocities. Then, the molecular formation routes corresponding to the abundances observed. These results are an initial step in investigating the specific chemical evolution of carbon chain molecules in star forming regions. The chemical makeup of star forming clouds leads directly into that of stellar systems; observing the chemical complexity of star formation and modeling its environment provides an invaluable link between these systems.

Optically active confined spins in solids such as semiconductor quantum dots, colour centres in diamond and atomic-scale defects in 2D-semiconductors are of interest for a wide range of applications in quantum science and technology. In the context of photon-based quantum technologies electron and hole spins localized in single quantum dots can be used for the high rate (~100\,MHz) on-demand generation of single photons with excellent quantum indistinguishability. This talk will provide a snapshot of the recent progress and challenges for quantum light sources, spin-photon interfaces, optical interconnection of distant spins, as well as outlining recent progress in quantum state detection using superconducting nanowires. Finally, we will also explore how spin states in emerging 2D-semiconductors provide fascinating perspectives in quantum sensing and metrology.

Unlike the Hertzsprung–Russell diagram for stars, there remains no formal classification for exoplanets composed of varying proportions of fluids, rock+metals and ice. Still, as with stars, planetary mass and composition – expressed in geochemical and cosmochemical terms – mold bulk physical characteristics and evolutionary paths. Here, I show how combining geodynamics with astrophysical observations provides insights into rocky exoplanet characteristics such as silicate mantle viscosity and intrinsic heat production vs. age. I test the general predictability of such geochemical models with an example from recent atmospheric retrieval data collected from an ultra-hot Jupiter in the WASP-76 system. I conclude with a geochemical evaluation of spectral data of moderately volatile vs. moderately refractory lithophile elements reported from some polluted white dwarfs and what this means for the ultimate fates of rocky planets around Sun-like stars

Paper: https://arxiv.org/abs/2311.13723

Format: pedagogical lecture (45 mins) and hands-on numerical simulations based on Julia (45 mins)

Open Access (OA) publishing has become a hot topic. Funders, research organisations, and universities are developing OA policies that researchers need to know about and adhere to. The fact that models for OA implementation vary and continue to evolve makes it difficult to stay well informed.

In this Informal Discussion, we will review the situation in OA publishing by looking at positive, but also negative aspects, along with a few issues that should be avoided altogether. We will also look at the OA models of major astronomy journals and evaluate if and how they are suited to establish a collaborative, equitable, sustainable publishing landscape.

Przybylski's star is probably one of the most unique stars of our Galaxy. Its spectrum is overloaded with lines of s-process elements. Quantitative analysis shows that the overabundance of these elements in the Przybylski's star atmosphere is enormous. The reason for this is unknown. I will briefly discuss new ideas that may help to better understand this mysterious star and its chemical anomalies.

How much do different physical processes in the interstellar medium -- in particular dynamics, magnetic field and density structure -- influence the formation of massive stars? I will show observational results covering scales of dynamical cloud-cloud collisions to collapsing star-forming regions. Employing studies from mm wavelengths (SMA, NOEMA, ALMA, 30m) to the mid-infrared (JWST), the characterisation of magnetic field, density structure and accretion processes will be discussed.

In today's dynamic landscape, where efficiency and innovation are pivotal, the Julia programming language (https://julialang.org/) demonstrated to be a revolution in scientific and data computing. This programming language got attention for its exceptional speed, versatility and easy to use. In the same line of Python, Julia is used in fields as diverse as finance, healthcare, engineering in addition to be widely used in particle physics. Oliver Schulz (MPP), developer of BAT.jl (Bayesian Analysis Toolkit), will provide a general introduction, background, and some pros and cons of Julia programming language.

Important note, this discussion will continue with some worked examples in the AI Forum at 14:00 (10/01/2024).

I will discuss recent advances in the understanding of globular star clusters from combining space-based data (Gaia parallaxes and proper motions, HST photometry) with data from large ground-based telescopes like the VLT. I will in particular discuss the initial mass function of globular clusters, the evolution of their black hole population and the possible presence of dark matter in globular clusters.

Paper: https://arxiv.org/pdf/2309.13115.pdf