A High-Resolution Radio Continuum Study of the Dwarf Irregular Galaxy IC10

Abstract

Dwarf galaxies are a significant contributor to the current star formation rate for the Universe as a whole, yet little is understood of what drives star formation in these low gas density environments. IC10 is a nearby dwarf irregular galaxy that is currently in a starburst phase making it an ideal place to study star formation and its effects on the interstellar medium in a low density setting. We present new high resolution (~1 pc) radio continuum maps of IC10 at λ=20cm (ν = 1.5GHz) taken with the e-MERLIN array. Maps were produced by reducing and combining data taken in two observational epochs, one in February and the other in November 2013. Inspection of the final maps reveal 8 compact sources coincident with extended emission, 4 of which are classified as HII regions and 4 as supernova remnants (SNR). We summarise some characteristic parameters for these candidates. Due to the lack of short baselines we detect much less flux than single dish observations, however the star formation derived from counting the individual SNR reveals a star formation rate consistent with the literature. Nearly all spatially resolved sources are coincident with regions of H-alpha emission, suggesting that they are the sites of current star formation. Interestingly, no compact sources were detected within the star forming non-thermal superbubble, either supporting that it is indeed a hypernova remnant or suggesting that SNRs within this region are too dim to be detected. Further information such as the spectral index of each observed source as well as higher resolution images will be required for further analysis.