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S. Emdadi, R.M. Sambruna (George Mason University), Michael Eracleous (Penn State University)
The Broad-Line Radio Galaxies 3C390.3 and 3C120 were observed with the Rossi X-ray Timing Explorer in 1996 and 1997, respectively. In both cases, the RXTE observations were part of a multiwavelength monitoring (PI: Remillard); here we present the results of the analysis of the archival RXTE data. 3C390.3 was monitored from 1996 May through July, with regular sampling of once a day for a month and once every three days for two months. 3C120 was observed from 1997 January through March with a similar sampling pattern. Both sources exhibit variability of the 2-15 keV flux, but with qualitatively different behaviors. 3C390.3 exhibits a trend of decreasing flux by a factor 2 in ~ 20 days, with smaller changes (~ a few percent) on timescales of 4 days or less superposed. In contrast, 3C120 exhibits more erratic flux variations similar to ``flickering'', with small-amplitude intra-day flares superposed on a constant baseline. Spectral variations are also observed, with a trend of steeper X-ray continuum with increasing flux. In 3C390.3, we investigated possible variations of the Fe Kalpha line flux with the flux of the X-ray continuum, in an attempt to determine the size of the cold reprocessor responsible for the Fe line emission ("X-ray reverberation mapping"). We find that, even with the large collecting area of the PCA, the Fe line flux is affected by large uncertainties (factor 2), hampering the detection of any Fe line variability.
This work is supported by NASA grant NAG5-10243.