A

Assessing Assembly Bias Through the Satellite Populations of X-ray–Selected Halos

Ilaria Marini (ESO), Victoria Toptun (ESO), Natanael de Isídio (ESO)

Galaxy groups and clusters are key environments for studying how galaxies evolve, because satellite galaxies in these systems experience a range of physical processes—such as gas stripping, starvation, and tidal interactions—that depend strongly on their surroundings. A useful way to characterize these environments is through their X-ray luminosity (Lx), which reflects the amount and density of hot gas in the system. Since Lx is linked not only to halo mass but also to a system’s formation history and the density of the surrounding large-scale structure, it may serve as a broader indicator of environmental conditions and possible assembly bias.

B

Tracing shock-driven shaping of molecular clouds as a trigger for star formation

Elena Redaelli (ESO), Marta De Simone (ESO)

Stars form from the collapse of overdensities in molecular clouds. But what triggers the formation of these overdensities and the subsequent gravitational collapse? External feedback, such as expanding bubbles or supernova-driven shocks, can compress the ambient gas and trigger sequences of shocks that reshape the cloud and promote star formation. This is, however, a difficult phenomenon to observe and characterise, and we still know little about it. This project will focus on examining NGC 1333 in the Perseus molecular cloud, a Solar-type star-forming region, where gas kinematics and chemistry show signs of shock-driven compression (De Simone et al. 2022a).  Using astrochemistry, the most powerful diagnostic tool to infer the dynamical and chemical properties of star-forming regions, and analysing different molecular species (such as SiO, SO, H2CS, CH3OH,…), the student will investigate how such energetic events can shape the morphology of the interstellar medium and the fate of future newborn stars.

C

Aligned, askew, or wildly tilted? Measuring an exoplanet’s orbit

Bibiana Prinoth (ESO), Jens Kammerer (ESO), Sydney Vach (ESO), Juliana Ehrhardt (ESO)

When a planet passes in front of its star, it consecutively covers different parts of the stellar surface. Because stars rotate, each portion of the stellar disc has a slightly different velocity. This creates a temporary distortion in the star’s spectrum during transit – known as the Rossiter–McLaughlin effect – and acts as a powerful tracer of how a planet’s orbit is oriented relative to the star’s spin, offering key insights into how planetary systems form and how their orbits evolve over time.

D

A turbulent youth: Investigating the conditions of planetary birthplaces

Jochen Stadler (ESO), Anna Miotello (ESO)

During their formation, baby stars are surrounded by a circumstellar disk composed of molecular gas and dust. From the material within these protoplanetary disks, planets eventually form. Observations made with the ALMA Observatory reveal that the millimeter dust emission of these disks exhibits a variety of substructures, most commonly observed are gaps and rings. These structures are believed to arise from variations in the gas pressure within the disk. Dust rings are prime places for the formation of planetary cores.

E

Excavating the fossil record of KILOGAS galaxies

Amelia Fraser-McKelvie (ESO), Nikki Geesink (ESO)

Clues to a galaxy’s past are concealed in the light that we observe today. Galactic archaeology techniques including spectral energy distribution (SED) fitting employs multiwavelength data from galaxies to infer their star formation activity across cosmic time. The ultraviolet to infrared spectra of all galaxies arises from stellar light, either directly, or reprocessed by the gas and dust of the surrounding interstellar medium. Each galaxy possesses a unique SED that contains a large amount of information about the stars of a galaxy from which we can derive information on its formation and evolution. This chemical ‘fingerprint’, coupled with information on the galaxy’s current star formation and cold gas reservoir, allows us to gain a complete picture of the gas-star formation cycle in nearby galaxies.

F

Centers of Dwarfs or the Outskirts of Giants: Where Do More Pristine Stars Form?

Martyna Chruslinska (ESO), Géza Csörnyei (ESO)

The chemical composition of material within galaxies evolves as elements produced inside stars are gradually released to the surrounding medium. New generations of stars then form from this enriched material, which affects their properties and their ability to produce a wide range of energetic cosmic events - from luminous explosions seen across the electromagnetic spectrum to the formation of black holes detected through gravitational waves.

G

From Molecular Lines to Physical Conditions: Teaching Neural Networks to Read the Interstellar Medium

Lukas Neumann (ESO), Caterina Bracci (ESO), Francesco Belfiore (ESO)

A major challenge in understanding star formation is determining the physical conditions of the interstellar medium, particularly the dense molecular gas closely associated with active star-forming regions. The most direct method relies on far-infrared dust emission, which is well mixed with the gas and can be modeled to infer temperature and column density. However, far-infrared observations require space-based facilities across infrared wavelengths that are currently not available and typically offer much lower angular resolution compared to modern radio and optical telescopes.