We investigate the case for environmental quenching of the Fornax-mass satellite DDO 113 , which lies only 9 kpc in projection from its host , the Large-Magellanic-Cloud-mass galaxy NGC 4214 .
DDO 113 was quenched about 1 Gyr ago and is virtually gas-free , while analogs in the field are predominantly star-forming and gas-rich .
We use deep imaging obtained with the Large Binocular Telescope to show that DDO 113 exhibits no evidence of tidal disruption to a surface brightness of \mu _ { V } \sim 29 mag \text { arcsec } ^ { -2 } , based on both unresolved emission and resolved stars .
Mass-analogs of DDO 113 in Illustris-1 with similar hosts , small projected separations , and no significant tidal stripping first fell into their host halo 2–6 Gyr ago , showing that tidal features ( or lack thereof ) can be used to constrain infall times in systems where there are few other constraints on the orbit of the satellite .
With the infall time setting the clock for environmental quenching mechanisms , we investigate the plausibility of several such mechanisms .
We find that strangulation , the cessation of cold gas inflows , is likely the dominant quenching mechanism for DDO 113 , requiring a time-averaged mass-loading factor of \eta = 6 - 11 for star-formation-driven outflows that is consistent with theoretical and observational constraints .
Motivated by recent numerical work , we connect DDO 113 ’ s strangulation to the presence of a cool circumgalactic medium ( CGM ) around NGC 4214 .
This discovery shows that the CGM of low-mass galaxies can affect their satellites significantly and motivates further work on understanding the baryon cycle in low-mass galaxies .