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Paper: Long Timescale X-ray Variability of 3C 273: Similarity to Seyfert Galaxies and Galactic Binary Systems
Volume: 350, Blazar Variability Workshop II: Entering the GLAST Era
Page: 94
Authors: McHardy, I.
Abstract: Long timescale (i.e. few years) X-ray monitoring of Seyfert galaxies shows that their power spectral densities (PSDs) are described by broken power laws and that the break timescales scale approximately linearly with black hole mass. Here we present a 2-10 keV X-ray light curve of 3C273 stretching back over 30 years. We determine the PSD using the same PSD modelling software that we use for Seyfert galaxies to account for light curves with gaps. Although 3C273 is dominated by jet emission in the 2-10 keV band, its PSD is identical to that of Seyfert galaxies in the ‘high’ state and a clear break is found. The similarity of the PSD shape of 3C273 to that of a Seyfert galaxy implies that the process with underlies the variability in jet dominated sources is the same as that which produces variations in non-beamed sources. This process is probably variations in the accretion rate which propagate inwards via the accretion disc into the corona and thence outwards into the jet. Interestingly, the break timescale is consistent with that which would be expected from a Seyfert galaxy with the same black hole mass; we do not have to invoke relativistic beaming and time dilation to achieve consistency. Thus the variations are probably produced by a source external to the jet rather than one moving with the jet.
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