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An exploratory study of the hard X-ray variability properties of PG quasars with RXTE

M. Guainazzi·F. Fiore·E. Giallongo·A. Laor·M. Elvis·A. Siemiginowska
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Abstract

We have monitored with the RXTE PCA the variability pattern of the 2-20 keV flux in four PG quasars (QSOs) from the Laor et al. (1994) sample. Six observations of each target at regular intervals of 1 day were performed. The sample comprises objects with extreme values of Balmer line width (and hence soft X-ray steepness) and spans about one order of magnitude in luminosity. The most robust result is that the variability amplitude decreases as energy increases. Several options for a possible ultimate driver of the soft and hard X-ray variability, such as the influx rate of Comptonizing relativistic particles, instabilities in the accretion flow or the number of X-ray active sites, are consistent with our results.

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M. Guainazzi, F. Fiore, E. Giallongo, A. Laor, M. Elvis, A. Siemiginowska. 2000-05-08. An exploratory study of the hard X-ray variability properties of PG quasars with RXTE. https://doi.org/10.1016/s1387-6473(00)00070-1

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