First MeerKAT Observations of the Brightest M31-M33 HI Cloud in the Circumgalactic Medium of M31

In 2004, Braun and Thilker discovered a bridge of extremely faint, diffuse HI gas connecting the galaxies M31 and M33. Follow-up, higher resolution observations by Wolfe et al. (2013, 2016) with the Green Bank Telescope (GBT) revealed that the filament broke up into higher column density clouds, with a total of nine individual and discrete clouds of HI discovered in the region surveyed. The nature of these clouds remains an open question. Potential origins of the clouds are speculated to include, the products of galaxy interactions, dwarf galaxies, high velocity clouds, dark matter sub-halos, gas in planes of satellites, a dark matter filament, or condensations of the circumgalactic medium of M31. The previous observations lacked the spatial and spectral resolution to probe the internal structure of the clouds in order to probe their nature, effectively limiting our understanding of these objects. We present the first MeerKAT observations of the brightest cloud in the filament.  Our initial analysis has made it clear that the superior spatial and spectral resolution of the MeerKAT observations reveal that the cloud has a more complex small-scale internal kinematic structure than anticipated.  We will discuss how this HI cloud compares to those clouds seen around the Milky Way and the implications for its potential origins.