We use a volume-limited spectroscopic sample of isolated galaxies in the Sloan Digital Sky Survey ( SDSS ) to investigate the frequency and radial distribution of luminous ( M _ { r } \lesssim - 18.3 ) satellites like the Large Magellanic Cloud ( LMC ) around \sim L _ { * } Milky Way analogs and compare our results object-by-object to \Lambda CDM predictions based on abundance matching in simulations .
We show that 12 \% of Milky Way-like galaxies host an LMC-like satellite within 75 kpc ( projected ) , and 42 \% within 250 kpc ( projected ) .
This implies \sim 10 \% have a satellite within the distance of the LMC , and \sim 40 \% of L _ { * } galaxies host a bright satellite within the virialized extent of their dark matter halos .
Remarkably , the simulation reproduces the observed frequency , radial dependence , velocity distribution , and luminosity function of observed secondaries exceptionally well , suggesting that \Lambda CDM provides an accurate reproduction of the observed Universe to galaxies as faint as L \sim 10 ^ { 9 } L _ { \odot } on \sim 50 kpc scales .
When stacked , the observed projected pairwise velocity dispersion of these satellites is \sigma \simeq 160 ~ { } { km s } ^ { -1 } , in agreement with abundance-matching expectations for their host halo masses .
Finally , bright satellites around L _ { * } primaries are significantly redder than typical galaxies in their luminosity range , indicating that environmental quenching is operating within galaxy-size dark matter halos that typically contain only a single bright satellite .
This redness trend is in stark contrast to the Milky Way ’ s LMC , which is unusually blue even for a field galaxy .
We suggest that the LMC ’ s discrepant color might be further evidence that it is undergoing a triggered star-formation event upon first infall .