Radio-frequency heating of emission-line gas near compact extragalactic radio sourcesHigh-brightness-temperature radio sources significantly heat by free-free absorption any nearby gas that has properties similar to those inferred for QSO emission-line gas. As a result, the outer layers of the gas clouds expand, and their visible line emission decreases. Moderate heating enhances the collisionally excited ultraviolet line of O VI at 1034 A. Stronger heating penetrates the entire cloud and extinguishes all lines. Strong enough radio fluxes cause a thermal instability by stimulated Compton heating that is only saturated by Compton cooling at very high temperatures. It is speculated that BL Lac objects differ from quasars by having higher radio turnover frequencies, lower gas pressures, or more violent variability, all of which make radio heating more effective.
Document ID
19790046035
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Krolik, J. H. (Institute for Advanced Study Princeton, N.J., United States)
Mckee, C. F. (California, University Berkeley, Calif., United States)
Tarter, C. B. (California, University Lawrence Livermore Laboratory, Livermore, Calif., United States)