The population of very low-mass satellites beyond the Local Group

The number and structural properties of the lowest-mass
galaxies (less than ~10^6 Msun) that accompany galaxies like the Milky Way are
key to ruling out different dark matter models. However, this population
remains hidden beyond the Local Group due to its low brightness. In this study,
we present the results of the LIGHTS survey in this area. With a current
surface brightness limit of 31 mag/arcsec², LIGTHS is the deepest survey of
Milky Way–like galaxies beyond the local group to date (typical distance ~15
Mpc). We will present the current detection limits and discuss what to expect
from the next generation of ultra-deep surveys, such as LSST or Arrakhis.