B. H. Andrew

Ten-year study of extragalactic variable sources at centimeter wavelengths

Observations of 99 suspected variable sources are presented. The observations cover periods of up to 10-1/2 yr at 2.8 cm and 7 yr at 4.5-cm wavelength. We conclude from the observations that bursts of particle generation occur in the average variable source about once every 1-1/2--2 yr. There seems to be a universal emission mechanism such that the maximum flux density S/sub max/(lambda) at wavelength lambda is proportional to lambda/sup -0.4/ for wavelengths in the range 1 to 10 cm.

OBSERVATIONS OF VARIABLE RADIO SOURCES AT 2.8 CM

Abstract : Thirty-one suspected variable radio sources have been observed between July 1966 and October 1967. Definite or possible variations have been detected in 21 of the sources. Some of the observed variations cannot be explained by the theory of an expanding cloud of relativistic electrons. (Author)

Variability of AO 0235|[plus]|164 at radio, optical, and infrared wavelengths

The most recent outburst of the BL Lacertae object AO 0235+164, in November 1975, was particularly large and built up very quickly. These three papers present measurements made at radio, optical and infrared wavelengths, and discuss the extent to which the emitting regions in each case are associated.

BL Lac (VRO 42.22.01): Simultaneous Radio and Optical Observations,

Abstract : During August and September 1972, simultaneous optical and radio observations were made of BL Lac (VRO 42.22.01) in an attempt to find correlated variations. The optical and radio variations have similar time scales, but the evidence for correlation is inconclusive. The rapid variations at radio wavelengths are highly polarized and seem to originate in a region that is optically thin and has a highly ordered magnetic field. (Author)

RADIO AND OPTICAL OBSERVATIONS OF THE SOURCE OZ-252

The source OZ-252 is associated with a quasi-stellar object that has a wide emission band at 5245 A. Key words: quasars - radio sources