330 MHz VLA Observations of 20 Galactic Supernova Remnants
Abstract:
We present 330 MHz images and integrated flux densities for 20 previously identified 1st quadrant Galactic Supernova Remnants SNRs. The observations were made in the D configuration of the VLA giving an angular resolution of -3 and providing good sensitivity to extended structure. Such emission, particularly if it is nonthermal, might be missed on higher frequency surveys due to confusion with the Galactic background and confusion with thermal sources in complex regions. Both problems are reduced by interferometric observations at this lower frequency. The flux densities presented can be used to anchor the low frequency end of the radio spectra of these sources, which are often poorly determined by previous observations at both high and low frequencies. The measurements presented here are also useful for distinguishing steeper spectrum shell-type emission from flatter spectrum plerionic emission for SNRs whose intrinsic morphological type is not well established.