A highly sensitive radio survey of symbiotic stars at 3.6 centimeters

Abstract

Results of a new highly sensitive radio survey of about 100 symbiotic stars at 3.6 cm are reported. The survey has led to the detection of about half of all the symbiotic stars searched, effectively doubling the number of known radio detections. The analysis shows that the radio emission is correlated strongly with emission in the mid-IR (12 and 25 microns) and less strongly with IR emission at both shorter and longer wavelengths. A comparison between the radio and UV continua (1300 A) indicates that the ionized nebula in nearly all symbiotic stars is optically thick and/or density bounded. In particular, there is evidence that S-types are more optically thick in the radio wavelength range than D-types.