Radio Continuum Mapping of the Spiral Galaxy NGC 4321

We have combined numerous, short radio continuum observations of the Virgo Cluster spiral galaxy NGC 4321 (M 100) made at 20 and 6 cm with the Very Large Array (VLA) to produce a deep map of the galaxy. These observations were originally taken for monitoring the radio supernova SN 1979C (Weiler et al. 1986, ApJ, 310, 790; 1991, ApJ, 380, 161) and is analogous to our recent work on NGC 6946 (Hyman et al. 1993, BAAS 25, 1322) using observations taken for monitoring SN 1980K. The maps we derive for NGC 4321 are of superior sensitivity (sigma ~ lt 0.05 mJy/beam at 20 cm) and spatial resolution ( ~ 2" at 20 cm) to those previously published by other investigators (e. g., Knapen et al. 1993, ApJ, 416, 563). We present preliminary measurements and analyses of detected thermal and nonthermal sources, including flux densities, spectral indices, and luminosities, particularly for the very strong circumnuclear radio source, known as a site of intense star formation (e. g., Arsenault et al. 1988, A&A, 200, 29). We also make comparisons of our radio maps with existing data at other wavelengths.