Extending Ultra-Diffuse Galaxy abundances to Milky Way analogues

ABSTRACT We extend the Ultra-Diffuse Galaxy (UDG) abundance relation, NUDG − M200, to lower halo mass hosts $(M_{200}\sim 10^{11.6-12.2}\, \mathrm{M}_{\odot })$. select UDG satellites from published catalogues of dwarf satellite galaxies around Milky Way analogues, namely Exploration Local Volume Satellites (ELVES) survey, Satellite Around Galactic Analogs (SAGA) and a survey Way-like systems conducted using Hyper-Suprime Cam. Of 516 total 75 hosts, we find that 41 33 satisfy criteria. The distributions host masses peak $M_{200}\sim 10^{12}\, }$, independent whether has or not. use literature abundances those derived here trace M200 relation over three orders magnitude down $M_{200}=10^{11.6}\, }$ best-fitting linear $N_{\mathrm{ UDG}} = (38\pm 5) (\frac{M_{200}}{10^{14}})^{0.89\,\,\pm ~ 0.04}$. This sub-linear slope is consistent with earlier studies as well relations for brighter galaxies, excluding UDG-formation mechanisms require high-density environments. However, highlight need further homogeneous characterization UDGs across wide range environments properly understand relation.