论文部分内容阅读
As a radio-loud narrow-line Seyfert 1 galaxy(NLS1)detected by Fermi/LAT in GeV gamma-ray,1H 0323+342 is a remarkable Active Galactic Nucleus(AGN)showing properties characteristic of both NLS1s and blazars.Here we present results of simultaneous Xrays and UV/optical monitoring observations on 1H 0323+342 taken with the UV/Optical Telescope and X-ray Telescope onboard the Swift satellite over six years from 2006.Overall,the object showed statistically correlated variations in both the UV and X-ray bands on timescale of years as well as on timescale of days.The latter,albeit with a large scatter,is found for the first time in a gamma-ray detected NLS1.A Suzaku observation with a 84 kilo-seconds exposure reveals X-ray variability on timescales as short as a few tens of thousand seconds,and an X-ray spectrum typical of Seyfert galaxies.The broad-band spectral energy distribution can be well modeled with a simple one-zone leptonic jet model plus accretion disk/corona emission; the latter is predominantly responsible for the UV/optical and X-ray(0.3–10 keV)emission and their variations observed.We interpret the correlated UV–X-ray variabilities on the timescale of days in terms of reprocessing of the X-ray radiation by the accretion disk.The shortest timescale and large normalized excess variance of the X-ray variability detected with Suzaku predict a relatively small black hole mass of the order of 107 solar masses,consistent with the estimation based on the broad optical emission line.