Evolution of LMC/M33-mass dwarf galaxies in the EAGLE simulation

Understand

We investigate the population of dwarf galaxies with stellar masses similar to the Large Magellanic Cloud (LMC) and M33 in the EAGLE galaxy formation simulation.

• In the field, galaxies reside in haloes with stellar-to-halo mass ratios of $1.03^{+0.50}_{-0.31}\times10^{-2}$ (68% confidence level); systems like the LMC, which have an SMC-mass satellite, reside in haloes about 1.3 times more massive, which suggests an LMC halo mass at infall, $M_{200}=3.4^{+1.8}_{-1.2}\times10^{11}M_\odot$ (68% confidence level).
• The colour distribution of dwarfs is bimodal, with the red galaxies ($g-r>0.6$) being mostly satellites.
• The fraction of red LMC-mass dwarfs is 15% for centrals, and for satellites this fraction increases rapidly with host mass: from 10% for satellites of Milky Way (MW)-mass haloes to nearly 90% for satellites of groups and clusters.