After the success of the first two installments of this conference series (“At the Edge of the Universe” in 2006 and “Back at the Edge of the Universe” in 2015), it’s time to return to beautiful Sintra and discuss the latest achievements of the deepest observations of the Universe.
This time, we find ourselves exploring the observations that were so eagerly anticipated 9 years ago (and mostly only dreamt of 18 years ago), in what is truly a transformative epoch in our understanding of galaxy formation and evolution. With remarkable observational facilities pushing the boundaries of the observable Universe to uncharted territory, from X-rays to radio wavelengths, we are now closer than ever to witnessing the formation of the first structures (stars, galaxies, clusters) in the Universe.
Are we living the moment when we finally grasp how galaxies form? Can we unveil the emergence of the first stars and determine if they fully account for the energetic radiation that reionised the neutral intergalactic medium? Can we finally pinpoint the role of supermassive black holes for galaxy assembly, and how they come to exist within a few hundred Myr after the Big Bang? Can the deepest observations reveal the intricate and evolving relationship between star-formation and AGN activity, leading to the quick establishment of galaxies?
Is the current generation of powerful space-based telescopes like JWST and EUCLID, and ground-based facilities such as ALMA, VLT or the SKA-precursors, able to settle one of the most pressing issues of modern research?
Continuing the tradition set by previous editions of this nine-year conference, we aim to analyse galaxy formation and evolution in the light of the deepest astronomical observations. The focus is on the latest observational results, and on how they shape, and are interpreted by, the latest theoretical framework.
The star-formation properties of galaxies and the central supermassive black holes that they host follow a tight co-evolution. Current structure formation models invoke Active Galactic Nucleus (AGN) feedback via quasar or radio modes at the high stellar mass ends, as well as feedback from supernovae at low stellar masses, to explain the observed number density of galaxies as a function of stellar mass and redshift. However, despite decades-long efforts both simulations and observations still struggle to reach a consensus on the physical mechanisms regulating star formation and feedback across all scales (from sub-parsec to mega-parsec) and across cosmic history (from the local universe to the first galaxies). The advancements of hydrodynamical and semi-analytical simulations in terms of improved physically motivated models, code efficiency, and hardware for HPC infrastructures now allow us to reach unprecedented numerical accuracy, but the sensitivity leap in recent and current observations is further challenging our understanding of galaxy formation in a cosmological context.
The conference will gather major experts to review the recent advancements in the field in the context of multi-wavelength observations and their comparison with theoretical and numerical models.
We are witnessing an exciting revolution in our understanding of the first billion years of cosmic history. The launch of the JWST has enabled the discovery of galaxies in the first few hundred million years, and their detailed characterization in terms of chemical enrichment, stellar populations, nuclear black hole properties, morphologies, and environment is ongoing. In addition to these stunning discoveries, there have also been recent probes of the dust content of galaxies in the first billion years with ALMA, and robust theoretical predictions are also essential for interpreting future observations with ELTs and “deep-wide field” observations with the Nancy Grace Roman telescope. At the same time, GAIA and SDSS-V are probing the chemical abundances of individual stars in our own Galaxy and in nearby galaxies, which provide complementary “fossil evidence” on the properties of the first stars and how early galaxies were enriched with the heavy elements that eventually made life on Earth possible. This wealth of data has the potential to paint a picture of unprecedented clarity and detail of the first billion years of cosmic evolution — provided we have robust and detailed theoretical models with which to interpret and stitch them together. The goal of this program is to provide a unique forum for theorists and observers specializing in different subfields to interact intensively with each other developing links between several synergistic areas, including star formation, stellar evolution, chemistry, radiation, gas physics, and cosmology.
The next generation of large-scale structure surveys such as Euclid, DESI, LSST, SPHEREx, and SKA is going to provide an unprecedented amount of observational data. These surveys will map large portions of the sky, observing hundreds of millions of bright galaxies up to high redshifts, effectively transforming cosmology into a data-driven, precision science. It is more and more important to develop the right techniques to efficiently extract information from this data. The large number of ongoing efforts reach from new summary statistics for efficient data compression to full forward models for field level analysis and use an expanded range of statistical techniques. For any of these, blind mock data challenges are an important tool to demonstrate the unbiased inference of cosmological parameters, where complications can arise from uncertainties about non-linear galaxy formation as well as observational systematics. This is the second workshop with the aim to gather a broad range of proposed (new and established) methods for the data analysis of next-generation surveys. It will also offer a platform to discuss those methods in the light of ongoing data challenges and to plan future ones. The goal is to share expertise between groups and to identify common obstacles and solutions for establishing an end-to-end pipeline that can be applied to real data.
Over the past two decades, observations have established samples of hundreds of luminous quasars, powered by accretion onto massive black holes, in the first billion years of the Universe. The James Webb Space Telescope (JWST) has significantly revised this sample by yielding unexpectedly numerous black holes with masses in the range of a few to a hundred million solar masses, within the first few hundred million years after the Big Bang, posing enormous challenges for black hole and galaxy formation models. On the other side of the redshift ladder, in the nearby Universe, JWST and ALMA are revealing the complex interplay of black hole accretion with their circumnuclear and galactic environment. Additionally, current and upcoming novel observations of stars torn apart by black holes? tides (a.k.a. Tidal Disruption Events, TDEs) by ZTF (Zwicky Transient Factory), the VRO/LSST and ULTRASAT hold promise to shedding light on the formation of massive black holes by uniquely expanding our knowledge of the scarcely populated low-mass end (less than one million solar masses) of the black hole mass function. Finally, massive black hole binaries (MBHBs) are sources of the gravitational waves (GWs) and naturally explain the stochastic GW background recently discovered by Pulsar Timing Arrays (PTAs). They will be detected by the Laser Interferometer Space Antenna (LISA) over the next decades, promising to directly reveal massive black holes with masses between 10 thousand and 10 million solar masses, virtually anywhere in the Universe.
Straddling the fields of cosmology, galaxy formation and black hole astrophysics, our symposium aims at bringing together communities working on different tracers of massive black hole formation and evolution, such as AGN, TDEs and MBHBs, both from the theoretical and observational standpoint, exploring and discussing constraints both in the local and distant Universe. The goals of the symposium are to discuss i) how the most recent observations can help establish a coherent picture of early black hole formation and their evolution through cosmic time, assess ii) what big and/or new questions remain open, and iii) how to address them with a combination of new theoretical developments and upcoming data.
By reviewing and discussing the most recent observational results, theoretical models and simulations, the symposium will provide a global perspective of how black hole formation, feeding and feedback happen in galaxies across cosmic time.
The summer 2024, two years after the beginning of JWST science operations, will be the right time to gauge its impact on the quantitative characterization of galaxies. This symposium will gather the main results from the peak of star formation activity at z~2 to the first galaxies alongside the latest major achievements from sensitive instrumentation at optical/near-infrared to millimeter wavelengths and theoretical interpretations.
More specific goals of the symposium follow:
First galaxies: statistical properties Detecting and characterizing first galaxies all the way to redshift ~20 has been a main focus of JWST so far. This session will discuss what we are learning from JWST observations and models in the EoR, covering available surveys at z > 6 (e.g. CEERS, GLASS, JADES, JEMS, PRIMER, NGDEEP, FRESCO, PANORAMIC) and synergies with other datasets (e.g., ALMA, NOEMA, VLT) focusing on: (i) the overall galaxy population, (ii) the progress of cosmic star-formation in the first billion years, with an emphasis put on the galaxy main sequence, luminosity function and stellar mass function. These distribution functions will be compared to models of galaxy formation specifically focusing at z>6 and implementing a range of different feedback processes and star-formation recipes.
First galaxies: from spectral diagnostics to physical properties With statistically robust samples of confirmed high-redshift galaxies in hand, and much improved constraints with JWST, it is the right time to discuss the nature of the first generation of galaxies interpreting their spectral diagnostics in terms of stellar/BH population properties (e.g., role of clusters, peculiar ionizing sources, role of early accreting black holes or binary stars) and ISM environment through which their photons travel before escaping. Chemical and radiative feedback processes (i.e. dust and metals production and H2 formation) from stars and central black holes (e.g., ionization state and gas temperature) will be covered and their impact on the multiphase ISM addressed. This session will also be an opportunity to discuss the adequacy of the modeling and interpretive tools in the physical regimes relevant to the earliest cosmic times.
The Baryon cycle Gas flows in and out galaxies and radial flows within disks are the mechanisms that maintain, promote, or suppress star formation in galaxies. Feedback from star formation and/or AGN plays a key role in regulating such flows. This active field of research for the ionized and the neutral phases (especially with the VLT and ALMA/NOEMA, respectively) is providing key physical insights essential to the interpretation of the observed stellar properties of galaxies across cosmic time.
First appearance and growth of quenched galaxies Besides actively star-forming galaxies at very high redshifts, JWST has also revealed the unexpected presence of both low- and high-mass quenched galaxies already in place in the first few billion years after Big Bang, and some of them had their star formation suppressed around, or even before, the epoch of reionization. Mapping the growth of such a population, in number, mass, size and morphology, is now being accomplished from cosmic dawn to noon, an indispensable step towards understanding the physical origin of star-formation quenching.
From early chaotic assembly to ordered disks First galaxies appear to be compact dwarfs, but by cosmic noon (z~2) most galaxies have settled into orderly-rotating disks. The detailed mapping of this transition as a function of time, for galaxies of all masses, is paramount to understanding the structural and stellar mass assembly of galaxies. With JWST, and the growing body of complementary resolved millimeter interferometric observations of gas kinematics, this is now well underway and will feature as a main item in this Session.
Structure and Dynamics of galaxies High spatial resolution observations from the ground (e.g., as currently being done with ALMA/NOEMA and ERIS at the VLT) and from space (e.g. NIRSpec IFU on the JWST) are revealing the internal kinematics and dynamics of star-forming galaxies, allowing us to gauge the relative distribution of baryon and dark matter on galactic scales and their interplay within galaxies in the early Universe.
Galaxy scaling relations (from NOON to DAWN) Scaling relations between fundamental properties, specifically SFR, size, gas, dust, metal content, and angular momentum all as a function of stellar mass and cosmic time, are key to constraining the dominant mode and timescale of galaxy evolution. Galaxy surveys over the last two decades have revealed the existence of tight and smoothly evolving scaling relations out to cosmic noon and beyond. Access to the rest-frame near-IR regime now provided by JWST will allow a most accurate determination of stellar masses as well as stellar population and size properties, setting scaling relations from cosmic noon to cosmic dawn on more solid grounds.
We are on the cusp of significant advancements to our understanding of the origins and early growth of massive black holes with current and near-future electromagnetic observations by JWST and other upcoming missions which will be complemented by gravitational wave detections with LISA in the coming decade. The focus of this conference is on recent advancements in both observations and theory on the origin, growth and dynamics of MBHs in the early Universe. Follow the pre-registration link above to let us know you are interested and you will receive an email when abstract submission is open!
Topics of interest:
Observations and predicted properties of AGN and their hosts at early times
Constraining MBH formation mechanisms with multimessenger observations at low and high redshift
Predictions for MBH seed masses from low redshift observations of dwarf galaxies
Challenges (both theoretical and observational) to observing and interpreting data on early MBHs
MBH-galaxy co-evolution and feedback in the early universe
Dynamics of MBHs and MBH binaries in the early Universe
How can we connect current and near-future E-M observations to future GW detections to do astrophysics?
Understanding the environment of high redshift MBHs and AGN and how it affects their early evolution
This workshop is a chance to discuss the nature and evolution of high redshift galaxies, from cosmic noon to re-ionization, as derived from a variety of observational evidence collected across the whole electromagnetic spectrum, and theoretical investigations.
In the tradition of the previous meetings we aim at bringing together members of the main extragalactic surveys and theorists to present their latest results and perspectives for the next future.
The workshop will be a chance to discuss the major questions on the ground, that will be address in specific sessions:
What drove the apparently accelerated early evolution of galaxy UV luminosity and mass, especially prior to z~10?
What was the primary early growth mechanism of supermassive black holes, and what is the role of the resulting active galactic nuclei (AGNs) in early galaxy evolution? Can we discriminate between different avenues for black hole formation and growth, and if not how can we in the future?
What was the evolution of the inter-galactic medium (IGM), and how does the evolving IGM affect the observations?Are we able to track the interplay between the early evolvution of galaxies and the IGM in a meaningful and self-consistent way
How did metals form in early galaxies, and what can we learn about galaxy formation from different abundance patterns
How well can we establish metal abundances in the young Universe with existing data?
How and when did dust form in early galaxies? How did it affect star formation, and how/when is it subsequently destroyed within, consumed by, or ejected from the evolving host galaxy?
Which quenching mechanisms were most effective as a function of galaxy properties, environment, and cosmic epoch. What are the key signatures of quenching on the evolving galaxy population?
After the success of the i2i conference (2022), we would like to re-apply for a follow-up workshop entitled “i2i: back again to linking galaxy physics from ISM to IGM scales”. Our application for a workshop is motivated by the fact that the datasets from facilities such as ALMA, NOEMA, MUSE and JWST are providing unrivaled glimpses of the earliest galaxies assembling in an infant Universe. These provide an unprecedented opportunity to baseline and enhance theoretical models. In this era forthcoming facilities including Euclid, SKA, ELT, EUCLID and LISA, it is also pertinent to discover and exploit the synergies between these different instruments in order to build a coherent picture of the Universe. Bringing together experts in ISM/CGM, galaxy formation and large-scale structure formation, our aim is to continue the discussion on establishing synergies between next-generation observatories using a combination of theoretical modelling and observations. We will address key outstanding questions including:
1. What is the key ISM physics governing the emission lines seen at high-redshifts? 2. What are the properties of the CGM that hold an appreciable gas component? 3. What were the IGM conditions (temperatures, ionization, metallicity) at early epochs? 4. How were galaxy formation and reionization driven by the interplay between galaxies and the IGM?
Effective communications skills, both oral and written are an essential part of scientific research. Whether you want to write a peer review article, a telescope proposal, or a research grant application, the outcome will depend critically on your ability to write with clarity, ambition and authority.
The school will be held in english, in person, and organized with lectures in the morning and practical hands-on session in small groups in the afternoon. The SOC will help the lecturers for these exercise sessions.
The meeting will be held in person. Information to reach the school location (Centro Universitario di Bertinoro) can be found here (https://www.ceub.it/contatti/?lang=en) There will be 2 buses from and to Bologna Centrale train station on Sunday, 1st of October (indicative departure time at 3pm and 6pm) and Friday, 6th of October.
