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

Journal Article · Thu Aug 20 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/701/2/1644; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21319529

Winter, Lisa M ^[1]; Mushotzky, Richard F ^[2]; Terashima, Yuichi ^[3]; Ueda, Yoshihiro ^[4]

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1. Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States)
2. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
3. Department of Physics, Ehime University, Matsuyama, Ehime 790-8577 (Japan)
4. Department of Astronomy, University of Kyoto, Kyoto 606-8502 (Japan)

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 {sub H} > 10{sup 25} cm{sup -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) X-ray 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.

• OSTI ID: 21319529
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 701; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
GALAXY NUCLEI
KEV RANGE
LUMINOSITY
TELESCOPES
X-RAY GALAXIES
X-RAY SPECTRA