New Views of IC 10 in the Radio

Abstract

In this thesis, we showcase new high-resolution VLA L-band data of IC 10, a dwarf irregular galaxy in the Local Group. IC 10 is a target of the Local Group L-band survey (LGLBS) due to its distance, location in the sky, and the fact that it is the only starbursting galaxy in the Local Group. Due to its low metallicity and proximity to the Milky Way, it is a unique candidate for studying star formation and galaxy formation in an environment similar to those in the early universe. This survey has both the highest spatial (4.5′′) and spectral (0.4 km/s) resolution HI 21-cm data of IC 10 to date and the highest spatial resolution (1.5′′) L-band 1.0 - 2.0 GHz continuum data. We create a catalog of compact continuum sources and classify them by their spectral index and position. We find 62 total sources, of these zero are identified as HII regions with α > −0.2, 19 are supernova remnants with a steep spectral index −0.8 < α < −0.2, and 43 are background galaxies with steep spectral indices α < −0.8. Using a spectral stacking technique, we compare CO (1-0) molecular gas emission with the HI 21-cm emission and recover ∼ 23% more emission than previously visible in the bright CO alone. Performing Gaussian decomposition on the HI and CO data we find the HI is composed of two components in many regions within the disk and we find that the CO emission is often but not necessarily associated with the brightest HI component. Lastly, we analyze an off-disk molecular cloud and find that it is surprisingly normal in its line widths, central velocities, and integrated intensity but displays a very high molecular gas fraction for its low dynamical equilibrium pressure due to the lack of a bright stellar population in the region.