Andrew Wetzel edited quenching_time.tex  about 9 years ago

Commit id: bb861e90d4570ad530783b2ec366f47eb81632ed

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Within each 1-dex bin of $\mstar$, we use the ELVIS simulations to compute the distribution of infall times that satellites at $z=0$ experienced.  Assuming that environmental quenching likelihood correlates with time since infall, we designate those that fell in earliest as having been quenched, and we adjust the time-since-infall threshold for quenching until we match the observed quiescent fraction in each bin.  Several works have shown that this model successfully describes the dependence of satellite quiescent fractions on host-centric distance \citep[e.g.,][]{Wetzel2013, Wetzel2014, Wheeler2014} because infall time correlates with host-centric distance \citep[e.g.,][]{Wetzel2015}.\textbf{XXX what about Rocha et al.? AW - they did not look at the correlation of infall time with distance, but rather as a function of orbital energy, unless there is something else that you had in mind.}  However, this correlation means that we must account for observed satellite's distances, including incompleteness at large distance for fainter satellites, in computing their infall times.  Thus, in selecting satellites in ELVIS, we only use those out to the maximum host-centric distance that they are observed from the MW or M31 in each $\mstar$ bin.  While this matters for the fainter satellites, we find that it is most important at $\mstar=10^{8-9}\msun$, because all such satellites (M32, NGC 205, LMC/SMC) reside $<61\kpc$ from the MW or M31.