On the influence of the Sun on the rapid variability of compact extragalactic sources

Abstract

Starting from December 2004, a program for the monitoring of intraday variable sources at a frequency of 5 GHz was performed at the Urumqi Observatory. The analysis of the variability characteristics of the flat-spectrum radio source AO 0235+164 revealed the existence of an annual cycle in the variability amplitude. This appears to correlate with the solar elongation of the source. A thorough analysis of the results of the MASIV IDV survey --- which provides the variability characteristics of a large sample of compact radio sources --- confirms that there is a small but detectable component of the observed fractional modulation which increases with decreasing solar elongation. We discuss the hypothesis that the phenomenon is related to interplanetary scintillation.

10 pages, 12 figures and 2 tables. Accepted for publication in Astronomy and Astrophysics

References in corpus (7)

• The Micro-Arcsecond Scintillation-Induced Variability (MASIV) Survey II: The First Four Epochs
• Radio-to-UV monitoring of AO 0235+164 by the WEBT and Swift during the 2006--2007 outburst
• Angular Broadening of Intraday Variable AGN. II. Interstellar and Intergalactic Scattering
• The IDV source J1128+5925, a new candidate for annual modulation?
• The radio lightcurve of SN 2008iz in M82 revealed by Urumqi observations
• A Compact Extreme Scattering Event Cloud Towards AO 0235+164
• Observations of IntraDay Variable sources with the Effelsberg and Urumqi Radio Telescopes

Cited by in corpus (4)

• Multi-wavelength Intra-day Variability and Quasi-periodic Oscillation in Blazars
• A seasonal cycle and an abrupt change in the variability characteristics of the intraday variable source S4 0954+65
• Multi-band Cross-correlated Radio Variability of the Blazar 3C 279
• Sun-related variability in the light curves of compact radio sources. A new view on Extreme Scattering Events