The x-ray spectral variability of the seyfert galaxy ngc 3227
Jun, 1998Citations per year
Abstract: (arXiv)
(Abridged) We present the results from {\it ASCA} observations of NGC 3227 along with those from a {\it ROSAT} observation. The 0.6--10 keV continuum is consistent with a powerlaw with , flatter than that typically observed in Seyfert galaxies. Fe -shell emission is observed with an EW and profile typical of Seyfert 1 galaxies. The {\it ASCA} observations in 1993 reveal absorption by a screen N_{H,z}^{ion} \simeq 3\times10^{21} cm^{-2}} of ionized material with . Joint analysis of the {\it ASCA} and {\it ROSAT} data show an additional screen of neutral material instrinsic to NGC 3227 with few\times10^{20} cm^{-2}}. NGC 3227 exhibits spectral variability both within and between the observations, due to short-term variability in the continuum emission and longer-term variability in the absorption. Time-resolved spectroscopy show the continuum steepened by during a flare of duration s. The column increased by a factor of by the 1995 epoch, while the continuum is consistent with that observed in 1993. The 1995 data also show evidence that the warm absorber allows 10% of the nuclear emission to escape without attenuation.References(57)
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