A Search for Radio Supernova Remnants in Four Irregular Galaxies
  We survey four nearby irregular galaxies for radio supernova remnants (SNRs)
using deep (1 sigma ~ 20 microJy), high resolution (~20 pc) VLA continuum data
at 20, 6, and 3.6 cm. We identify discrete sources in these galaxies and use
radio spectral indices and H alpha images to categorize them as SNRs, H II
regions, or background radio galaxies. Our classifications are generally in
good agreement agreement with the literature. We identify a total of 43 SNR
candidates: 23 in NGC 1569, 7 in NGC 4214, 5 in NGC 2366, and 8 in NGC 4449.
Only one SNR--the well-studied object J1228+441 in NGC 4449--is more luminous
at 20 cm than Cas A. By comparing the total thermal flux density in each galaxy
to that localized in H II regions, we conclude that a significant fraction must
be in a diffuse component or in low-luminosity H II regions.
