Maria Celeste Artale - Galaxy-Halo Connection

The Galaxy-Halo connection

Within the current standard cosmological scenario, galaxies form and evolve within dark matter haloes. It is well established that the formation and growth of galaxies across cosmic time depends on the dark matter halo properties. Understanding which are the main drivers that connect galaxies with their dark matter haloes is fundamental for galaxy formation models and to constrain cosmological models from galaxy surveys. In the last couple of years, I have worked in different aspects of the "galaxy-dark matter halo connection" by using hydrodynamical cosmological simulations.

Occupancy Variations in hydrodynamical cosmological simulations

In Artale et al. (2018) we investigated the occupancy variations, i.e., how the halo occupation depends on formation time and environment of the dark matter haloes, at fixed halo mass. In this work we use the galaxy and dark matter catalogues from EAGLE and Illustris simulations. Our results show that low-mass haloes in the densest environment are more likely to host a massive central galaxy, than those in low-dense environments. We also find that early-formed haloes host more massive galaxies than late-formed haloes.

Left panel: Halo occupation distribution (HOD) for the 20% oldest and 20% youngest haloes at a fixed halo mass (red and blue lines, respectively). Black lines represent the HOD using the full selected sample, based on a number density threshold on 0.01 h^3/Mpc^3

Right panel: Halo occupation distribution for the 20% haloes in the high and low dense regions at a fixed halo mass (red and blue lines, respectively).

For further details: https://ui.adsabs.harvard.edu/abs/2018MNRAS.480.3978A/abstract

Galaxy Alignments

The spatial distribution of galaxies at small and large scales provides information on how baryons assemble to form galaxies. In two recent works, we study the galaxy alignment of central galaxies with the surrounding structures, for a sample of the Sloan Digital Sky Server Data Release 16, and for the IllustrisTNG300 simulation (Rodriguez et al. 2022 a, b). [more details soon]