English

What determines satellite galaxy disruption?

Cosmology and Nongalactic Astrophysics 2015-05-13 v3 Astrophysics of Galaxies

Abstract

In hierarchical structure formation, dark matter halos that merge with larger halos can persist as subhalos. These subhalos are likely hosts of visible galaxies. While the dense halo environment rapidly strips subhalos of their dark mass, the compact luminous material can remain intact for some time, making the correspondence of galaxies with severely stripped subhalos unclear. Many galaxy evolution models assume that satellite galaxies eventually merge with their central galaxy, but this ignores the possibility of satellite tidal disruption. We use a high-resolution NN-body simulation of cosmological volume to explore satellite galaxy merging/disruption criteria based on dark matter subhalo dynamics. We explore the impact that satellite merging/disruption has on the Halo Occupation Distribution and radial profile of the remnants. Using abundance matching to assign stellar mass/luminosity to subhalos, we compare with observed galaxy clustering, satellite fractions, cluster satellite luminosity functions, finding that subhalos reproduce well these observables on all scales. Our results imply that satellite subhalos corresponding to >0.2L* galaxies must be well-resolved down to 1-3% of their mass at infall to robustly trace the galaxy population. We also explore a simple analytic model based on dynamical friction for satellite galaxy infall, finding good agreement with our subhalo catalog and observations.

Keywords

Cite

@article{arxiv.0907.0702,
  title  = {What determines satellite galaxy disruption?},
  author = {Andrew R. Wetzel and Martin White},
  journal= {arXiv preprint arXiv:0907.0702},
  year   = {2015}
}

Comments

19 pages, 14 figures, accepted for publication in MNRAS

R2 v1 2026-06-21T13:21:17.954Z