Millimeter-wave and X-ray observations of a Cen-A flare

The simultaneous observations of Cen A made in December 1979 at 22 GHz (Itapetinga) and soft X rays (Ariel-5) are discussed. It is noted that a significant radio flare was detected. In phase X-ray excess emission, which was not significant, is discussed. A short-term series of daily observations obtained at 13.5 mm wavelength, displaying a distinctive rise-and-fall flare, is reported, and the corresponding data obtained in the low-energy X-ray range (4-10 keV) are discussed.