A1 Refereed original research article in a scientific journal
Results of long-term monitoring of 3C 273 over a wide range of wavelengths
Authors: Vol'vach AE, Kutkin AM, Vol'vach LN, Larionov MG, Lakhteenmaki A, Tornikoski M, Nieppola E, Tammi J, Savolainen P, Leon-Tavares J, Aller MF, Aller HD
Publisher: MAIK NAUKA/INTERPERIODICA/SPRINGER
Publication year: 2013
Journal: Astronomicheskii Zhurnal / Astronomy Reports
Journal name in source: ASTRONOMY REPORTS
Journal acronym: ASTRON REP+
Number in series: 1
Volume: 57
Issue: 1
First page : 34
Last page: 45
Number of pages: 12
ISSN: 1063-7729
DOI: https://doi.org/10.1134/S1063772912050083
Abstract
The results of long-term monitoring of the quasar 3C 273 at wavelengths from radio to gamma rays between 1963 and 2011 are presented. The variations of the source flux density are studied using harmonic and wavelet analysis techniques. The values and frequency-time localizations of harmonic components in the flux-density variations are determined. The eight-year radio-variability period reported earlier had become gradually reduced and attenuated by 2000. The optical light curve has a component with a quasi-period of approximately 13 years. Cyclic variations whose periodicity gradually increased from approximately one to two years were observed in the X-ray between 1996 and 2006. The relative time delays between the light curves at different radio frequences are determined. The frequency dependence of time delays is approximated by the power law, Delta T(nu) ae nu (-1/k) with k = 1.4 +/- 0.1, which can be used to infer the corresponding core shift and estimate the core-region magnetic field as B (1 pc) = 0.5 +/- 0.1 G. This approach is preferable to other methods, since it does not require multi-frequency VLBI observations and is a simple and effective tool for studying Active Galactic Nuclei.
The results of long-term monitoring of the quasar 3C 273 at wavelengths from radio to gamma rays between 1963 and 2011 are presented. The variations of the source flux density are studied using harmonic and wavelet analysis techniques. The values and frequency-time localizations of harmonic components in the flux-density variations are determined. The eight-year radio-variability period reported earlier had become gradually reduced and attenuated by 2000. The optical light curve has a component with a quasi-period of approximately 13 years. Cyclic variations whose periodicity gradually increased from approximately one to two years were observed in the X-ray between 1996 and 2006. The relative time delays between the light curves at different radio frequences are determined. The frequency dependence of time delays is approximated by the power law, Delta T(nu) ae nu (-1/k) with k = 1.4 +/- 0.1, which can be used to infer the corresponding core shift and estimate the core-region magnetic field as B (1 pc) = 0.5 +/- 0.1 G. This approach is preferable to other methods, since it does not require multi-frequency VLBI observations and is a simple and effective tool for studying Active Galactic Nuclei.
UTU Research Portal