A Radio Survey of Symbiotic Stars

The results of a VLA survey of 59 symbiotic stars at 4.9 GHz are presented. Seventeen of these were detected as radio sources, and eight of the detected stars were also observed at 1.5 GHz. The majority of the radio detections have large H-beta equivalent width, and there is also a positive correlation between radio luminosity and the spectral type of the red giant component. The radio emission is consistent with optically thick thermal bremsstrahlung from an ionized gas in all cases. A model is discussed in which the hot companion in a binary system ionizes a portion of a stellar wind from the late-type giant. Mass loss rates ranging from 10 to the -7th to 10 to the -6th solar mass/yr appear to be consistent with the radio emission.