The galaxy size-halo mass scaling relations of central and satellite galaxies

FACUNDO RODRIGUEZ; ANTONIO D. MONTERO-DORTA; M. CELESTE ARTALE

Córdoba

Congreso; COSMOSUR VI COSMOLOGY AND GRAVITATION IN THE SOUTHERN CONE; 2022

Observatorio Astronómico de Córdoba

This work explores the scaling relations for a sample of central and satellite galaxies from the Sloan Digital Sky Survey (SDSS). We show that while these galaxies have similar stellar mass-to-size ratios, their halo mass-to-size ratios differ significantly. More massive haloes tend to host larger central galaxies. However, the size of satellite galaxies shows almost no dependence on halo mass. We show that these results are compatible with a remarkably simple model in which the size of central and satellite galaxies scales as the cube root of the mass of their host halo, with the normalisation of satellites being $sim 30%$ smaller than that of central galaxies, which can be attributed, for example, to removal by tidal forces. Furthermore, we find that our measurements are in excellent agreement with the predictions of the IllustrisTNG 300 hydrodynamical simulation.