With the advant of ASCA and its capability for high-resolution X-ray spectroscopy it has become possible to study the X-ray emission lines from AGNs and their very broad profiles. The Fe Kalpha line is particularly important because it is by far the strongest X-ray line observable in AGN spectra. Its profile carries the kinematic signature of the line-emitting gas and as such is constitutes an extremely useful diagnostic tool. XTE complements ASCA in at least the following obvious ways: (a) since the PCA bandpass can extend in practice up to 15-20 keV (up to 40 keV in principle) it is possible to study the signature of Compton reflection from the same dense gas that emits the Fe Kalpha line observed by ASCA, and (b) its large effective area and flexible scheduling policies allow us to monitor the variability of the X-ray spectrum (flux, shape, EW of Fe Kalpha line, and strength of Compton-reflected X-rays). We have tried to take advantage of the strengths of XTE by observing the hard X-ray spectra and variability broad-line radio galaxies. Accordingly, I will review the properties of the broad-line radio galaxies as observed by ASCA in order to motivate the XTE projects that we have undertaken. I will then present the (preliminary) results of our hard X-ray spectroscopy of Pictor A and 3C 111 and our 2-month monitoring of the X-ray variability of 3C 390.3.
American Astronomical Society Meeting Abstracts #192
- Pub Date:
- May 1998