Andrew Wetzel edited summary_discussion.tex  about 9 years ago

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We conclude by briefly discussing the complex dependence of satellite quenching timescales on $\mstar$ from Figure~\ref{fig:quench_times} in the context of the underlying physics of environmental quenching.  At $\mstar\gtrsim10^9\msun$, the long quenching timescales suggests quenching driven by gas depletion in the absence of cosmic accretion after infall (``strangulation''), caused by gravitational tidal stripping and/or ram-pressure stripping of the extended gas around the satellite.  Furthermore, this scenario explains the decline of the quenching timescale with increasing $\mstar$, because higher-mass galaxies generally have lower $\mgas/\mstar$ \citep[in either cold atomic or molecular gas, e.g.,][Bradford et al., submitted]{Schiminovich2010,Saintonge2011a,Huang2012,Boselli2014} submitted]{Schiminovich2010,Huang2012,Boselli2014}  and thus shorter gas depletion timescales in the absence of accretion. Indeed, at $\mstar\sim10^9\msun$, galaxies transition through $\mgas/\mstar\approx1$, with gas depletion timescales comparable to a Hubble time.  In this scenario, the quenching timescales at $\mstar\gtrsim10^9\msun$ do not necessarily require strong additional environmental processes other than the lack of gas accretion to account for quenching in satellites \citep[see related discussions in, e.g.,][]{Wetzel2013,Wheeler2014,McGee2014}.