| タイトル | NuSTAR and XMM-Newton Observations of Luminous, Heavily Obscured, Wise-Selected Quasars at Z Is Approximately 2 |
| 本文（外部サイト） | http://hdl.handle.net/2060/20150010993 |
| 著者（英） | LaMassa, S. M.; Harrison, F. A.; Craig, W. W.; Christensen, F. E.; Benford, D.; Ghandi, P.; Alexander, D. M.; Yan, L.; Del Moro, A.; Jarrett, T. H.; Zhang, W. W.; Stern, Daniel K.; Urry, C. M.; Tsai, C.-W.; Wright, E. L.; Griffith, R. L.; Brandt, W. N.; Blain, A.; Balokovic, M.; Assef, R. J.; Comastri, A.; Bauer, F. E.; Brightman, M.; Eisenhardt, P. R. M.; Boggs, S. E.; Luo, B.; Wu, J.; Lansbury, G. B.; Ballantyne, D. R.; Hailey, C. J.; Koss, M.; Lake, S.; Walton, D. J.; Bridge, C.; Hickox, R. C. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2014-09-29 |
| 言語 | eng |
| 内容記述 | We report on a NuSTAR and XMM-Newton program that has observed a sample of three extremely luminous, heavily obscured WISE-selected active galactic nuclei (AGNs) at z (is) approximately 2 across a broad X-ray band (0.1 79 keV). The parent sample, selected to be faint or undetected in the WISE 3.4 micrometers (W1) and 4.6 micrometers (W2) bands but bright at 12 micrometers (W3) and 22 micrometers (W4), are extremely rare, with only (is) approximately 1000 so-called "W1W2-dropouts" across the extragalactic sky. Optical spectroscopy reveals typical redshifts of z (is) approximately 2 for this population, implying rest-frame mid-IR luminosities of L(6 micrometers) (is) approximately 610(exp 46) erg s1 and bolometric luminosities that can exceed L(sub bol) (is) approximately 10(exp 14) L solar luminosity. The corresponding intrinsic, unobscured hard X-ray luminosities are L(2-10 keV) (is) approximately 4 10( exp 45) erg s1 for typical quasar templates. These are among the most AGNs known, though the optical spectra rarely show evidence of a broad-line region and the selection criteria imply heavy obscuration even at rest-frame 1 micrometers. We designed our X-ray observations to obtain robust detections for gas column densities NH (is) less than 10(exp 24) cm2. In fact, the sources prove to be fainter than these predictions. Two of the sources were observed by both NuSTAR and XMM-Newton, with neither being detected by NuSTAR (f3-24 keV 10(exp -13) erg cm2 s1), and one being faintly detected by XMM-Newton (f(sub 0).5-10 keV (is) approximately 5 10(exp -15) erg cm(exp -2) s1). A third source was observed only with XMM-Newton, yielding a faint detection (f0.5-10 keV (is) approximately 7 10(exp -15) erg cm(exp -2) s1). The X-ray data imply these sources are either X-ray weak, or are heavily obscured by column densities NH 1024 cm2. The combined X-ray and mid-IR analysis seems to favor this second possibility, implying the sources are extremely obscured, consistent with Compton-thick, luminous quasars. The discovery of a significant population of heavily obscured, extremely luminous AGNs would not conform to the standard paradigm of a receding torus, in which more luminous quasars are less likely to be obscured, and instead suggests that an additional source of obscuration is present in these extreme sources |
| NASA分類 | Astrophysics |
| レポートNO | GSFC-E-DAA-TN21674 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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