THE SUZAKU VIEW OF THE SWIFT/BAT ACTIVE GALACTIC NUCLEI. II. TIME VARIABILITY AND SPECTRA OF FIVE "HIDDEN" ACTIVE GALACTIC NUCLEI

被引:29
作者
Winter, Lisa M. [1 ]
Mushotzky, Richard F. [2 ]
Terashima, Yuichi [3 ]
Ueda, Yoshihiro [4 ]
机构
[1] Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA
[2] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[3] Ehime Univ, Dept Phys, Matsuyama, Ehime 7908577, Japan
[4] Kyoto Univ, Dept Astron, Kyoto 6068502, Japan
关键词
galaxies: active; X-rays: galaxies; X-RAY SPECTROSCOPY; XMM-NEWTON; CIRCINUS GALAXY; COMPTON-THICK; RATE INDICATOR; PG QUASARS; BAT SURVEY; FEK LINES; AGN; REFLECTION;
D O I
10.1088/0004-637X/701/2/1644
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The fraction of Compton-thick sources is one of the main uncertainties left in understanding the active galactic nucleus (AGN) population. The Swift Burst Alert Telescope (BAT) all-sky survey for the first time gives us an unbiased sample of AGNs for all but the most heavily absorbed sources N-H > 10(25) cm(-2)). Still, the BAT spectra (14-195 keV) are time averaged over months of observations and therefore hard to compare with softer spectra from the Swift XRT or other missions. This makes it difficult to distinguish between Compton-thin and Compton-thick models. With Suzaku, we have obtained simultaneous hard (> 15 keV) and soft (0.3-10 keV) Xray spectra for five Compton-thick candidate sources. We report on the spectra and a comparison with the BAT and earlier XMM observations. Based on both flux variability and spectral shape, we conclude that these hidden sources are not Compton thick. We also report on a possible correlation between excess variance and Swift BAT luminosity from the 16 day binned light curves, which holds true for a sample of both absorbed (four sources), unabsorbed (eight sources), and Compton-thick (Circinus) AGNs, but is weak in the 64 day binned BAT light curves.
引用
收藏
页码:1644 / 1664
页数:21
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