NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-05-24 T11:11:57 PDT
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For refcode 2010ApJS..187..581S:
Retrieve 36 NED objects in this reference.
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Copyright by American Astronomical Society. Reproduced by permission
2010ApJS..187..581S The Cores of the Fe K{alpha} Lines in Active Galactic Nuclei: An Extended Chandra High Energy Grating Sample Shu, X. W.; Yaqoob, T.; Wang, J. X. Abstract. We extend the study of the core of the Fe K{alpha} emission line at ~6.4 keV in Seyfert galaxies reported by Yaqoob & Padmanabhan using a larger sample observed by the Chandra high-energy grating (HEG). The sample consists of 82 observations of 36 unique sources with z < 0.3. Whilst heavily obscured active galactic nuclei are excluded from the sample, these data offer some of the highest precision measurements of the peak energy of the Fe K{alpha} line, and the highest spectral resolution measurements of the width of the core of the line in unobscured and moderately obscured (N_H_ < 10^23^ cm^--2^) Seyfert galaxies to date. From an empirical and uniform analysis, we present measurements of the Fe Kalpha line centroid energy, flux, equivalent width (EW), and intrinsic width (FWHM). The Fe K{alpha} line is detected in 33 sources, and its centroid energy is constrained in 32 sources. In 27 sources, the statistical quality of the data is good enough to yield measurements of the FWHM. We find that the distribution in the line centroid energy is strongly peaked around the value for neutral Fe, with over 80% of the observations giving values in the range 6.38-6.43 keV. Including statistical errors, 30 out of 32 sources (~94%) have a line centroid energy in the range 6.35-6.47 keV. The mean EW, among the observations in which a non-zero lower limit could be measured, was 53 +/- 3 eV. The mean FWHM from the subsample of 27 sources was 2060 +/- 230 km s^--1^. The mean EW and FWHM are somewhat higher when multiple observations for a given source are averaged. From a comparison with the H{beta} optical emission-line widths (or, for one source, Bralpha), we find that there is no universal location of the Fe K{alpha} line-emitting region relative to the optical broad-line region (BLR). In general, a given source may have contributions to the Fe K{alpha} line flux from parsec-scale distances from the putative black hole, down to matter a factor ~2 closer to the black hole than the BLR. We confirm the presence of the X-ray Baldwin effect, an anti-correlation between the Fe K{alpha} line EW and X-ray continuum luminosity. The HEG data have enabled isolation of this effect to the narrow core of the Fe K{alpha} line. Key words: galaxies: active, line: profiles, X-rays: galaxies
Retrieve 36 NED objects in this reference.
Please click here for ADS abstract

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