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Nustar observations of heavily obscured quasars at z is approximately 0.5
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Urry, C. M. Brandt, W. N. Balokovic, M. Elvis, M. Lansbury, G. B. LaMassa, S. M. Gandhi, P. Boggs, S. E. Mullaney, J. R. Ballantyne, D. R. Craig, W. W. Assef, R. J. Hailey, C. J. Stern, D. Harrison, F. A. Aird, J. Koss, M. Alexander, D. M. Christensen, F. E. Bauer, F. E. Del Moro, A. Hickox, R. C. Grefenstette, B. W. Teng, S. H. Luo, B. Zhang, W. W. |
| Copyright Year | 2014 |
| Description | We present NuSTAR hard X-ray observations of three Type 2 quasars at z approx. = 0.4-0.5, optically selected from the Sloan Digital Sky Survey. Although the quasars show evidence for being heavily obscured, Compton-thick systems on the basis of the 2-10 keV to [O(sub III)] luminosity ratio and multiwavelength diagnostics, their X-ray absorbing column densities (N(sub H)) are poorly known. In this analysis, (1) we study X-ray emission at greater than 10 keV, where X-rays from the central black hole are relatively unabsorbed, in order to better constrain N(sub H). (2) We further characterize the physical properties of the sources through broad-band near-UV to mid-IR spectral energy distribution analyses. One of the quasars is detected with NuSTAR at greater than 8 keV with a no-source probability of less than 0.1%, and its X-ray band ratio suggests near Compton-thick absorption with N(sub H) is approximately greater than 5 Ã 10(exp 23) cm(exp -2). The other two quasars are undetected, and have low X-ray to mid-IR luminosity ratios in both the low-energy (2-10 keV) and high-energy (10-40 keV) X-ray regimes that are consistent with extreme, Compton-thick absorption (N(sub H) is approximately greater than 10(exp 24) cm(exp â2)). We find that for quasars at z is approximately 0.5, NuSTAR provides a significant improvement compared to lower energy (less than 10 keV) Chandra and XMM-Newton observations alone, as higher column densities can now be directly constrained. |
| File Size | 543992 |
| Page Count | 10 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20150008983 |
| Archival Resource Key | ark:/13960/t28966k5q |
| Language | English |
| Publisher Date | 2014-03-21 |
| Access Restriction | Open |
| Subject Keyword | Quasars Nustar Luminosity Ratio Spacecraft Instruments Galaxies Luminosity Emission X Rays Space Missions Electromagnetic Spectra Spectrum Analysis Infrared Radiation X Ray Astrophysics Facility Compton Effect Black Holes Astronomy Xmm-newton Telescope Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
