MeerKAT HI commissioning observations of MHONGOOSE galaxy ESO 302-G014

TL;DR

This paper presents MeerKAT HI observations of the dwarf galaxy ESO 302-G014, revealing asymmetric gas features and potential interactions, as part of preparations for the MHONGOOSE galaxy survey to study gas accretion and star formation.

Contribution

First detailed MeerKAT HI observations of ESO 302-G014, highlighting gas morphology and interaction signatures, supporting future studies of gas accretion in galaxies.

Findings

Asymmetric, lopsided outer HI disc.

Presence of HI tail and isolated cloud.

Evidence suggesting minor interaction with a low-mass galaxy.

Abstract

We present the results of three commissioning HI observations obtained with the MeerKAT radio telescope. These observations make up part of the preparation for the forthcoming MHONGOOSE nearby galaxy survey, which is a MeerKAT large survey project that will study the accretion of gas in galaxies and the link between gas and star formation. We used the available HI data sets, along with ancillary data at other wavelengths, to study the morphology of the MHONGOOSE sample galaxy, ESO 302-G014, which is a nearby gas-rich dwarf galaxy. We find that ESO 302-G014 has a lopsided, asymmetric outer disc with a low column density. In addition, we find a tail or filament of HI clouds extending away from the galaxy, as well as an isolated HI cloud some 20 kpc to the south of the galaxy. We suggest that these features indicate a minor interaction with a low-mass galaxy. Optical imaging shows a possible dwarf galaxy near the tail, but based on the current data, we cannot confirm any association with ESO 302-G014. Nonetheless, an interaction scenario with some kind of low-mass companion is still supported by the presence of a significant amount of molecular gas, which is almost equal to the stellar mass, and a number of prominent stellar clusters, which suggest recently triggered star formation. These data show that MeerKAT produces exquisite imaging data. The forthcoming full-depth survey observations of ESO 302-G014 and other sample galaxies will, therefore, offer insights into the fate of neutral gas as it moves from the intergalactic medium onto galaxies.