MHONGOOSE: A MeerKAT nearby galaxy survey

Abstract

The MHONGOOSE (MeerKAT Observations of Nearby Galactic Objects: Observing Southern Emitters) survey maps the distribution and kinematics of the neutral atomic hydrogen ( gas in and around 30 nearby star-forming spiral and dwarf galaxies to extremely low column densities. The column density sensitivity (3sigma over 16 ranges from $ $ cm$^ $ at $90''$ resolution to $ $ cm$^ $ at the highest resolution of $7''$. The mass sensitivity ($3 over 50 is $ at a distance of 10 Mpc (the median distance of the sample galaxies). The velocity resolution of the data is 1.4 One of the main science goals of the survey is the detection of cold accreting gas in the outskirts of the sample galaxies. The sample was selected to cover a range in masses from $10^7$ to almost in order to optimally sample possible accretion scenarios and environments. The distance to the sample galaxies ranges from 3 to 23 Mpc. In this paper, we present the sample selection, survey design, and observation and reduction procedures. We compared the integrated fluxes based on the MeerKAT data with those derived from single-dish measurement and find good agreement, indicating that our MeerKAT observations are recovering all flux. We present moment maps of the entire sample based on the first ten percent of the survey data, and find that a comparison of the zeroth- and second-moment values shows a clear separation in the physical properties of the between areas with star formation and areas without related to the formation of a cold neutral medium. Finally, we give an overview of the companion and satellite galaxies in the 30 fields, five of which have not previously been cataloged. We find a clear relation between the number of companion galaxies and the mass of the main target galaxy.