Programme

Lecture overview
The goal of the lectures would be to give the students the state-of-the-art understanding of the Milky Way, both from a theoretical and observational perspective. By discussing the latest insights from cosmological simulations, methodological approaches, and the available datasets, I aim to set the stage for addressing open questions by exploring simulations or (preparing) for the analysis of new datasets. This will enable the students to work on small projects addressing some of the questions with the current datasets, and be prepared for the exploitation of those released in the near future (e.g. Gaia DR4 will be released in December 2026).

Student project
Available soon .

Lecture overview
It is well known that galaxy interaction affects not only the morphology of the interacting galaxies but also the star formation, chemical enrichment history, kinematics, and dynamics of their stellar populations. The Magellanic Clouds are one of the closest pairs of interacting galaxies to the Milky Way, and because of this, their stellar populations can be resolved into individual stars. This allows for a detailed analysis of the astrophysical properties of their star cluster systems. For these reasons, the Magellanic Clouds are the ideal laboratories in which to test theoretical models that predict the dynamical history of this type of satellite galaxy. The VISCACHA photometric survey, which brings together researchers from Brazil, Chile, Argentina, Mexico, the United States, and Poland, along with its spectroscopic follow-up (the GMOS Trinational Project), has been systematically observing the star cluster system of the Magellanic Clouds using the SAMI (SOAR, Chile) and GMOS (Gemini South, Chile) instruments. In this course, I will summarize the current state of knowledge regarding the dynamical history of the Magellanic Clouds, the VISCACHA survey, and its main contributions. I will also introduce students to one of the most effective spectroscopic techniques for determining the metallicities of Star Clusters: the Calcium Triplet Technique (CaT)

Student project
Available soon

Lecture overview
Within the current paradigm of galaxy formation, dark matter halos act as the structural framework on which galaxies are built, growing hierarchically through mergers and the accretion of material. As baryons cool and condense within these halos, they give rise to the diverse population of galaxies we observe today. However, even among halos of similar mass, galaxies exhibit remarkable diversity in morphology, kinematics, and chemical structure. This diversity reflects the complex interplay between secular processes, external interactions, and environmental effects, which operate on different timescales and regulate star formation, the redistribution of material, and gas accretion. In this course, I will explore how morphological and kinematic distortions,such as warps, corrugations, and lopsidedness,serve as dynamical tracers of these processes. Based on results obtained from high-resolution cosmological simulations, such as IllustrisTNG and Auriga, I will discuss how these perturbations arise and what they reveal about i) their star formation histories (SFH), ii) the redistribution of pre-existing material, and iii) the accretion of new material.

Student project
Available soon

Lecture overview
RR Lyrae stars are considered the quintessential standard candle for Population II. Present and relatively abundant in old (>10 Gyr) and metal-poor stellar populations, RR Lyrae are found in every component of the Milky Way, globular clusters, all types of dwarf and ultra-faint galaxies in the Local Group and beyond. They are very precise standard candles offering distances with precisions down to a few percent and being quite luminous, they can probe the tridimensional structure of large volumes of our Galaxy and its surroundings. In these lectures I will give an overview on RR Lyrae properties, the state-of-the-art on RR Lyrae catalogues and calibrations that enable their optimal use as both standard candles and color standards; principles for the inference of tracer selection functions and the use of RR Lyrae as extinction probes; and a short overview of recent scientific results on the shape of the Galactic halo and disc, as well as the apparently striking nature of disc RR Lyrae themselves.

Student project
RR Lyrae are commonly used to trace the tridimensional structure of the Milky Way and neighboring galaxies, usually by parametrizing the density profile in a convenient and simplified mathematical form, e.g. a flattened or triaxial power law for the halo or a double exponential for the disc. In this project our goal will be to take advantage of the vast coverage and depth of current RR Lyrae surveys to explore the structure of the MW and possibly the LMC/SMC using a non-parametric estimator of RR Lyrae density which will allow us to explore non-axisymmetries, radial truncation profiles and local and global phenomena such as corrugations, flares, lopsidedness and warps. The project will involve using compilations of the latest large-scale RR Lyrae catalogues (Lucey et al. 2026, Cabrera-Gadea et al. 2025b) and publicly available tools to derive the selection function needed for completeness corrections (Mateu et. al. 2020, 2024, github/rrl_completess) as well as tools for a simple bayesian density estimation method (Ivezic et al. 2005).

Suggested Pre-reading:
Lucey et al. 2026. link
Cabrera-Gadea, Mateu & Ramos 2025. link
Mateu et al. 2020.link
Mateu et al. 2024 (AAS notes)link
Ivezic et al. 2005 (Appendix B)link

Lecture overview
Within the currently favored Λ-Cold Dark Matter cosmological model, stellar halos of Milky Way (MW)-mass galaxies grow in mass hierarchically through the accretion of smaller objects that, due to gravity, merge together to form the larger systems we see today. Tidal debris from this merging and accretion process forms a stellar halo extending to large radii that remains very structured owing to long dynamical times. Thus, the outskirts of galaxies preserve memory of their assembly history with high fidelity, offering unique insight into the accretion and growth history of galaxies. During the last decade there has been much progress, both from the observational and numerical side, to characterize stellar halos of Milky Way-mass galaxies. In these lectures, we will discuss how we can use resolved stellar populations to study in detail the origin of stellar halos in nearby galaxies. We will explore the main results both from Hubble Space Telescope and ground-based Subaru observations and hydrodynamical cosmological simulations that allow us to link the observed properties of stellar halos with the accretion history of their host galaxies. We will also explore how studies of stellar halos of galaxies will become increasingly important within the next decade, with JWST but in the near future with the arrival of the next generation of ground-based giant telescopes such as GMT and ELT as well as the space Roman Telescope.

Student project
Available soon

Lecture overview
In these lectures, I will discuss several mechanisms through which dark matter (DM) may have been produced in the early Universe. We begin by reviewing the traditional thermal production of weakly interacting massive particles (WIMPs) via the so-called freeze-out mechanism. In this scenario, dark matter particles are initially in thermal equilibrium with the plasma and subsequently decouple once their annihilation rate drops below the expansion rate of the Universe. We will then turn to scenarios in which dark matter particles, characterized by extremely small couplings to Standard Model (SM) particles, never attain thermal equilibrium. In such cases, dark matter can instead be produced through the decays or annihilations of other particles via the “freeze-in” mechanism. This framework is often associated with lighter dark matter candidates, with masses around the MeV scale, and leads to a rich and distinctive phenomenology. Finally, focusing on even lighter candidates, we will study the production of axions through the misalignment mechanism. For each of these dark matter scenarios, we will explore the relevant phenomenology, with particular emphasis on the prospects for direct detection.

Student project
Available soon.

Lecture overview
This lecture will explore techniques for identifying and analyzing stellar streams in wide-field photometric surveys. We will cover methods for stream discovery in large datasets, approaches to characterizing their morphological properties, and modeling and inference techniques including simulation-based inference (SBI). The lesson will include hands-on experience working with real data from the Dark Energy Survey (DES), the DECam Local Volume Exploration Survey (DELVE), and the Rubin Observatory’s LSST Data Preview 2 (DP2).

Student project
Available soon

Lecture overview
Galactic mergers are ubiquitous to the growth of galaxies in the Universe. During such events galaxies undergo major morphological transformations that depend on properties such as mass of the galaxies, and orbital configuration. The Milky Way (MW) hosts two particularly interesting 1:10 mass ratio mergers: the ongoing interaction between the Large and Small Magellanic Clouds (LMC and SMC) and their concurrent merger with the MW itself. What are the properties of these mergers and what have we learned from them? In this lecture series, I will review our current understanding on the properties of these mergers based on the current observational evidence and state-of-the-art N-body simulations. I will review the physical mechanisms that take place during a galactic merger and the current techniques that we use to simulate them. Finally, I will discuss how measurements of stellar tracer kinematics in the MW, LMC, and SMC are allowing us to map the structure and dynamical state of their DM halos. With data from Gaia DR4, Rubin, and 4MOST among others we will soon be able to measure the properties of these mergers with unprecedented accuracy.

Student project
Rewinding the orbits of Milky Way stellar halo tracers: Using the publicly available codes such as Gala and Agama, the students will learn how to integrate orbits of halo tracers, such as stars, streams, globular clusters, and satellite galaxies, in time-dependent MW potentials that include the effect of the LMC.

Suggested Pre-reading:
For the lectures
The effect of the LMC on the Milky Way System. Vasiliev, Eugene et. al., 2023. link
Hunting for the Dark Matter Wake Induced by the Large Magellanic Cloud, Garavito-Camargo et. al., 2019. link
For the project
The Orbital Histories of Magellanic Satellites Using Gaia DR2 Proper Motions. Patel, Ekta et. al., (2020). link

Lecture overview
In this lecture series I will present the main features of the Local Group, and give a broad overview of their history, how they are structured and how they evolve. I will then concentrate on the dynamics of the stellar populations of the Local Group, spanning from the largest structures down to the relatively insignificant stellar streams that fascinate me in particular. This will give us a big-picture scientific canvas on which to explore and test new ideas in machine learning that are particularly well adapted to the high-precision requirements of physics and particularly dynamics. I will present and demonstrate a variety of tools that we are developing, including new ways to potentially discover physics, and new ways to build “world models”. Along the way I hope to be able to get you up to speed on some of the powerful new modelling tools we have at our disposal.

Student project
1) AI-Kepler: Let’s automatically (re-)discover the laws of planetary motion from data using symbolic regression tied to a second-order optimizer!
2) LeMondeModèle: Let’s force neural net latent spaces to encode physics in an interpretable way!
3) Symplectomania: Let’s build a Hamiltonian flow for a simple dynamical system!

Lecture overview
In this lecture series, I will provide an overview of our current knowledge of the assembly history of M31 based on studies of its resolved stellar populations, with a focus on the kinematical and chemical properties of the stellar halo and tidal substructure, N-body and cosmological models for M31’s last significant merger event and its impact on the kinematics and structure of the disk, and the properties and dynamics of the satellite and globular cluster systems of M31. I will discuss the implications of each of these topics for the accretion history and dark matter distribution of M31. In addition, I will highlight the observational datasets that have led to these discoveries, focusing on large Hubble Space Telescope treasury surveys and ground-based spectroscopic surveys, including proper-motion based analyses enabled by Gaia in the M31 system, and discuss the science enabled by current and upcoming facilities like JWST and the Roman Space Telescope in M31. This overview will be unified under the umbrella of the M31 system as a pathfinder for near-field cosmology in the local universe.

Student project
In this project, students will combine constraints from HST-based star formation histories from PHAT and JWST-based chemical abundance measurements of individual stars in the disk of M31 to analyze how M31’s global starburst–which was presumably triggered by its interaction with the satellite progenitor of its last significant merger–impacts the chemical evolution of M31. This project will follow the methodology described in Escala et al. 2026 (in the LMC/SMC) to introduce the students in more detail to measurements from HST/JWST data, chemical evolution models, and statistical modeling frameworks, toward a more comprehensive understanding how resolved stellar populations trace galaxy-scale merger events.

Suggested Pre-reading:
Williams et al. 2015:. link
Nidever et al. 2024. link
Escala et al. 2026 (Section 4.1): link
Escala et al. 2021 (Section 1, Section 4.2, and references therein for the interested reader):link