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A. Zdziarski (N. Copernicus Astron. Ctr., Warsaw, Poland), P. Lubinski (Heavy Ion Laboratory, Univ. of Warsaw, Poland), G. M. Madejski (NASA/Goddard Space Flight Center)
We study the shape of the Fe K lines in Seyfert 1s using the ASCA\/ database. We find the lines to be much weaker, narrower, and less redshifted than previously thought. When modeling the underlying continuum of individual observations as a power law in the 3--10 keV range, the average Gaussian width and the equivalent width are about 200 eV and 100 eV, respectively, and the average peak energy is 6.4 keV. Taking into account Compton reflection leads to a further reduction of the widths. We also obtain the average line profile of Seyfert 1s, which consists of a weak intrinsically-narrow K\alpha component, a K\beta component merged with the K edge, and a broader component with the Gaussian width of a few hundred eV and the equivalent width of about 50--100 eV. The broader component can also be fitted by a line from a disk truncated below about 100 gravitational radii. We do confirm previous findings of strong, very broad, and redshifted Fe K\alpha lines in a few objects, e.g., in MCG --6-30-15, but such lines are not\/ typical to Seyfert 1s as a class.