
%0 Journal Article
%A Krichbaum, T. P. 
%A Kraus, A. 
%A Fuhrmann, L. 
%A Cim&ograve;, G. 
%A Witzel, A. 
%T Intraday Variability in Northern Hemisphere Radio Sources
%J Publications of the Astronomical Society of Australia
%D 2002/06/28
%V 19
%N 1
%P 14-18
%K quasars: general &#8212; quasars: individual (0716+71, 0917+62, 0954+65) &#8212; radio continuum: ISM &#8212; scattering
%R https://doi.org/10.1071/AS01085
%U https://www.publish.csiro.au/paper/AS01085 
%X We summarise results from flux density monitoring campaigns performed with the 100 m radio telescope at Effelsberg and the VLA during the past 15 yrs. We briefly discuss some of the statistical properties from now more than 40 high declination sources (&#948; &ge; 30&#176;), which show intraday variability (IDV). In general, IDV is more pronounced for sources with flat radio spectra and compact VLBI structures. For 0917+62, we present new VLBI images which suggest that the variability pattern is modified by the occurrence of new jet components. For 0716+71, we show the first detection of IDV at millimetre wavelengths (32 GHz). For the physical interpretation of the IDV phenomenon, a complex source and frequency dependent superposition of interstellar scintillation and source intrinsic variability should be considered. 
