Rapid optical variability in radio-quiet QSOs |
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| Authors: | Gopal-Krishna Alok C Gupta Ram Sagar Paul J Wiita U S Chaubey C S Stalin |
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| Institution: | National Centre for Radio Astrophysics, TIFR, Poona University Campus, Post Bag No. 3, Ganeshkhind, Pune 411007, India;Uttar Pradesh State Observatory, Naini Tal, 263129, India;Department of Physics, Gorakhpur University, Gorakhpur 273009, India;Astronomy and Astrophysics Division, Physical Research Laboratory, Navarangpura, Ahmedabad 380 009, India;Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA |
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| Abstract: | We report results of the observations at the Vainu Bappu Observatory and the Uttar Pradesh State Observatory of eight radio-quiet quasi-stellar objects (RQQSOs) during 1996–99. This is a part of our ongoing programme to search for intranight optical variability in RQQSOs. Additional evidence for very rapid variability in three of the five optically bright and very luminous RQQSOs we had observed earlier, 1049?006, 1444+408 and 1630+377, was found. Of the three newly observed RQQSOs, the data for 0043+039 are too noisy to allow conclusions about variability to be drawn, but 0748+294 and 0824+098 show strong hints of microvariability. We also present a summary of the results from our entire programme to date, which includes observations of 16 radio-quiet QSOs and one radio-weak QSO, and compare the general properties of rapid variability in radio-quiet versus radio-loud AGN as determined from our work and that of several other groups. Observations of this kind are likely to play a key role in understanding the relative contributions of accretion discs and relativistic plasma jets to rapid optical fluctuations of AGN. |
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| Keywords: | galaxies: active galaxies: jets galaxies: photometry quasars: general |
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