The transformation and quenching of simulated gas-rich dwarf satellites within a group environment
Abstract
The underlying mechanisms driving the quenching of dwarf-mass satellite galaxies remain poorly constrained, but recent studies suggest they are particularly inefficient for those satellites with stellar mass 109 M⊙. We investigate the characteristic evolution of these systems with chemodynamical simulations and idealized models of their tidal/hydrodynamic interactions within the 10^{13-13.5}-M⊙ group-mass hosts in which they are preferentially quenched. Our fiducial simulations highlight the role played by secular star formation and stellar bars, and demonstrate a transition from a gas-rich to passive, H I-deficient state (i.e. ΔSFR ≤ -1, def_{H I}} ≥ 0.5) within 6 Gyr of first infall. Furthermore, in the 8-10 Gyr in which these systems have typically been resident within group hosts, the bulge-to-total ratio of an initially bulgeless disc can increase to 0.3 < B/T < 0.4, its specific angular momentum λR reduce to ∼0.5, and strong bisymmetries formed. Ultimately, this scenario yields satellites resembling dwarf S0s, a result that holds for a variety of infall inclinations/harassments albeit with broad scatter. The key assumptions here lie in the rapid removal of the satellite's gaseous halo upon virial infall, and the satellite's local intragroup medium density being defined by the host's spherically averaged profile. We demonstrate how quenching can be greatly enhanced if the satellite lies in an overdensity, consistent with recent cosmological-scale simulations but contrasting with observationally inferred quenching mechanisms/time-scales; an appraisal of these results with respect to the apparent preferential formation of dS0s/S0s in groups is also given.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- October 2015
- DOI:
- 10.1093/mnras/stv1593
- arXiv:
- arXiv:1507.04104
- Bibcode:
- 2015MNRAS.453...14Y
- Keywords:
-
- galaxies: dwarf;
- galaxies: interactions;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 16 pages, 3 tables, 13 figures, Accepted for publication in MNRAS