Present-day descendants of z = 3 Lyα-emitting galaxies in the Millennium-II halo merger trees

Using the Millennium-II Simulation dark matter sub-halo merger histories, we created mock catalogs of Lyα-emitting (LAE) galaxies at z = 3.1 to study the properties of their descendants. Several models were created by selecting the sub-halos to match the number density and typical dark matter mass determined from observations of these galaxies. We used mass-based and age-based selection criteria to study their effects on descendant populations at z ≃ 2, 1, and 0. For the models that best represent LAEs at z = 3.1, the z = 0 descendants have a median dark matter halo mass of 10^12.7 M, with a wide scatter in masses (50% between 10^11.8 and 10 ^13.7 M). Our study differentiated between central and satellite sub-halos and found that 55% of z = 0 descendants are central sub-halos with M _Median 10¹². This confirms that central z = 0 descendants of z = 3.1 LAEs have halo masses typical of L*-type galaxies. The satellite sub-halos reside in group/cluster environments with dark matter masses around 10¹⁴ M. The median descendant mass is robust to various methods of age determination, but it could vary by a factor of five due to current observational uncertainties in the clustering of LAEs used to determine their typical z = 3.1 dark matter mass.