Andrew Wetzel edited observations.tex  about 9 years ago

Commit id: 5c845e52cac5eb43418760d9cebf2a4fb03bda85

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In addition to the data in \citet{McConnachie2012}, we also include the more recent measurements or upper limits of cold atomic gas mass from \citet{Spekkens2014}.  We do not include the recently discovered ultra-faint satellites of the MW from the Dark Energy Survey \citep{Koposov2015, DES2015}, though if they are all quiescent galaxies, their inclusion would not change our results.  Observed dwarf galaxies show a tight correlation between their morphology, star formation, and cold gas content: alldwarf  spheroidals have little-to-no detectable cold gas or ongoing star formation, and almost all ofthe dwarf  irregulars have significant cold gas mass and ongoing star formation. Thus, we define ``quiescent'' satellites as those that have $\mgas/\mstar<0.1$ or are classified as having spheroidal morphology if they have no cold gas constraints.  By this definition, the only star-forming, gas-rich satellites in the LG are: LMC ($\mstar=1.5\times10^9\msun$, $\mgas/\mstar\approx0.3$) and SMC ($\mstar=4.6\times10^8\msun$, $\mgas/\mstar\sim1$) around the MW, and LGS 3 ($\mstar=9.6\times10^5\msun$, $\mgas/\mstar\approx0.4$) and IC 10 ($\mstar=9\times10^7$, $\mgas/\mstar\approx0.6$) around M31.  %(While Sculptor has $\mgas / \mstar \approx 0.096$, we consider it quiescent based on its morphology and lack of recent star formation \citep{Weisz2014a}).