Satellites Around Milky Way Analogs: Tension in the Number and Fraction of Quiescent Satellites Seen in Observations Versus Simulations
Ananthan Karunakaran, Kristine Spekkens, Kyle A. Oman, Christine M., Simpson, Azadeh Fattahi, David J. Sand, Paul Bennet, Denija Crnojevi\'c,, Carlos S. Frenk, Facundo A. G\'omez, Robert J. J. Grand, Michael G. Jones,, Federico Marinacci, Bur\c{c}in Mutlu-Pakdil

TL;DR
This study compares observed and simulated satellite galaxy properties around Milky Way-like hosts, revealing a significant discrepancy in the fraction of quenched satellites below a certain stellar mass, which challenges current models.
Contribution
It provides a detailed comparison of star-formation activity in satellites from observations and simulations, highlighting a persistent discrepancy that suggests missing physics in models.
Findings
Observed satellites have fewer quenched low-mass satellites than simulations.
Good agreement in star-forming satellite counts and SFRs between observations and simulations.
Discrepancy persists across different tracers and simulation resolutions.
Abstract
We compare the star-forming properties of satellites around Milky Way (MW) analogs from the Stage~II release of the Satellites Around Galactic Analogs Survey (SAGA-II) to those from the APOSTLE and Auriga cosmological zoom-in simulation suites. We use archival GALEX UV imaging as a star-formation indicator for the SAGA-II sample and derive star-formation rates (SFRs) to compare with those from APOSTLE and Auriga. We compare our detection rates from the NUV and FUV bands to the SAGA-II H detections and find that they are broadly consistent with over of observed satellites detected in all three tracers. We apply the same spatial selection criteria used around SAGA-II hosts to select satellites around the MW-like hosts in APOSTLE and Auriga. We find very good overall agreement in the derived SFRs for the star-forming satellites as well as the number of star-forming…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
