Noise characteristics of full-disc helioseismic observations made by resonant scattering spectrometers |
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| Authors: | W J Chaplin Y Elsworth G R Isaak B A Miller R New B Pintér † |
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| Institution: | IUCAA, Post Bag 4, Ganeshkhind, Pune 411 007, India;State Observatory, Manora Peak, Naini Tal 263 129, India;Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019, India;National Centre for Radio Astrophysics, TIFR, Pune University Campus, Post Bag 3, Pune 411 007, India;Institut d'Astrophysique de Paris, 98 bis, Bd. Arago, Paris 75014, France;Department of Physics &Astronomy, Georgia State University, PO Box 4106, Atlanta, GA 30302-4106, USA;Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263 129, India |
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| Abstract: | We report monitoring observations of 20 high-luminosity active galactic nuclei (AGN), 12 of which are radio-quiet quasars (RQQs). Intranight optical variability (INOV) was detected for 13 of the 20 objects, including 5 RQQs. The variations are distinctly stronger and more frequent for blazars than for the other AGN classes. By combining these data with results obtained earlier in our programme, we have formed an enlarged sample consisting of 9 BL Lacs, 19 RQQs and 11 lobe-dominated radio-loud quasars (RLQs). The moderate level of rapid optical variability found for both RQQs and radio lobe-dominated quasars (LDQs) argues against a direct link between INOV and radio loudness. We supplemented the present observations of 3 BL Lacs with additional data from the literature. In this extended sample of 12 well observed BL Lacs, stronger INOV is found for the EGRET detected subset. |
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| Keywords: | galaxies: active BL Lacertae objects: general galaxies: jets galaxies: photometry quasars: general |
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