NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-06-26 T00:59:01 PDT
Help | Comment | NED Home

For refcode 2006ApJ...644..725J:
Retrieve 100 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2006ApJ...644..725J On the X-Ray Baldwin Effect for Narrow Fe K{alpha} Emission Lines P. Jiang, J. X. Wang, and T. G. Wang Abstract. Most active galactic nuclei (AGNs) exhibit a narrow Fe K{alpha}line at ~6.4 keV in the X-ray spectra, due to the fluorescent emission from cold material far from the inner accretion disk. Using XMM-Newton observations, Page et al. found that the equivalent width (EW) of the narrow Fe K{alpha} line decreases with increasing luminosity (EW{propto}L^-0.17+/-0.08^), suggesting a decrease in the covering factor of the material emitting the line (presumably the torus). By combining the archival Chandra HETG observations of 34 type 1 AGNs with XMM observations in the literature, we build a much larger sample with 101 AGNs. We find a similar X-ray Baldwin effect in the sample (EW{propto}L^-0.2015+/-0.0426^); however, we note that the anticorrelation is dominated by the radio-loud AGNs in the sample, whose X-ray spectra might be contaminated by the relativistic jet. Excluding the radio-loud AGNs, we find a much weaker anticorrelation (EW{propto}L^-0.1019+/-0.0524^). We present Monte Carlo simulations showing that such a weak anticorrelation can be attributed to the relative short timescale variations of the X-ray continuum. Key words: Galaxies: Active, Galaxies: Quasars: Emission Lines, X-Rays: Galaxies
Retrieve 100 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home