Satellite mass functions and the faint end of the galaxy mass-halo mass relation in LCDM

Understand

The abundance of the faintest galaxies provides insight into the nature of dark matter and the process of dwarf galaxy formation.

• In the LCDM scenario, low mass halos are so numerous that the efficiency of dwarf formation must decline sharply with decreasing halo mass in order to accommodate the relative scarcity of observed dwarfs and satellites in the Local Group.
• The nature of this decline contains important clues to the mechanisms regulating the onset of galaxy formation in the faintest systems.
• We explore here two possible models for the stellar mass ($M_*$)-halo mass ($M_{200}$) relation at the faint end, motivated by some of the latest LCDM cosmological hydrodynamical simulations.