Systematically Measuring Ultradiffuse Galaxies (SMUDGes). IV. Ultradiffuse Satellites of Milky Way Analogs

DOI: 
10.3847/1538-3881/acf4f4
Publication date: 
11/11/2023
Main author: 
Goto, Hina
IAA authors: 
Karunakaran, Ananthan
Authors: 
Goto, Hina;Zaritsky, Dennis;Karunakaran, Ananthan;Donnerstein, Richard;Sand, David J.
Journal: 
The Astronomical Journal
Publication type: 
Article
Volume: 
166
Pages: 
185
Abstract: 
To better understand the formation of large, low-surface-brightness galaxies, we measure the correlation function between ultradiffuse galaxy (UDG) candidates and Milky Way analogs (MWAs). We find that: (1) the projected radial distribution of UDG satellites (projected surface density ∝r <SUP>-0.84±0.06</SUP>) is consistent with that of normal satellite galaxies; (2) the number of UDG satellites per MWA (S <SUB>UDG</SUB>) is ~0.5 ± 0.1 over projected radii from 20 to 250 kpc and -17 &lt; M <SUB> r </SUB> &lt; -13.5; (3) S <SUB>UDG</SUB> is consistent with a linear extrapolation of the relationship between the number of UDGs per halo versus halo mass obtained over galaxy group and cluster scales; (4) red UDG satellites dominate the population of UDG satellites (~80%); (5) over the range of satellite magnitudes studied, UDG satellites comprise ~10% of the satellite galaxy population of MWAs; and (6) a significant fraction of these (~13%) have estimated total masses &gt;10<SUP>10.9</SUP> M <SUB>⊙</SUB> or, equivalently, at least half the halo mass of the LMC, and populate a large fraction (~18%) of the expected subhalos down to these masses. All of these results suggest a close association between the overall low-mass galaxy population and UDGs, which we interpret as favoring models where UDG formation principally occurs within the general context of low-mass galaxy formation over models invoking more exotic physical processes specifically invoked to form UDGs.
Database: 
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2023AJ....166..185G/abstract
ADS Bibcode: 
2023AJ....166..185G
Keywords: 
Low surface brightness galaxies;Galaxy properties;940;615;Astrophysics - Astrophysics of Galaxies