Browsing by Author "Ballantyne, D. R."
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- ItemBroad-band X-ray spectral analysis of the Seyfert 1 galaxy GRS 1734-292(2017) Tortosa, A.; Marinucci, A.; Matt, G.; Bianchi, S.; La Franca, F.; Ballantyne, D. R.; Boorman, P. G.; Fabian, A. C.; Farrah, D.; Ricci, Claudio; Fuerst, F.; Gandhi, P.; Harrison, F. A.; Koss, M. J.; Stern, D.; Ursini, F.; Walton, D. J.
- ItemDetermining the covering factor of compton-thick active galactic nuclei with NuSTAR(2015) Brightman, M.; Balokovic, M.; Stern, D.; Arevalo, P.; Ballantyne, D. R.; Bauer, Franz Erik; Bogg, S. E.; Craig, W. W.; Christensen, F. E.; Comastri, A.; Gandhi, P.; Hailey, C. J.; Harrison, F. A.; Hickox, R. C.; Koss, M.; Lamassa, S.; Fuerst, F.; Puccetti, S.; Rivers, E.; Vasudevan, R.; Walton, D. J.; Zhang, W. W.
- ItemIC 3639—A NEW BONA FIDE COMPTON-THICK AGN UNVEILED BY NuSTAR(2016) Boorman, Peter G.; Gandhi, P.; Alexander, D. M.; Annuar, A.; Ballantyne, D. R.; Bauer, Franz Erik; Boggs, S. E.; Brandt, W. N.; Brightman, M.; Christensen, F. E.; Craig, W. W.; Farrah, D.; Hailey, C. J.; Harrison, F. A.; Hönig, S. F.; Koss, M.; LaMassa, S. M.; Masini, A. C.; Ricci, G.; Risaliti, D.; Stern, W.; Zhang, W.
- ItemNuSTAR observations of four nearby X-ray faint AGNs: low luminosity or heavy obscuration?(OUP, 2020) Annuar, A.; Alexander, D. M.; Gandhi, P.; Lansbury, G. B.; Asmus, D.; Balokovic, M.; Ballantyne, D. R.; Bauer, Franz Erik; Boorman, P. G.; Brandt, W. N.; Brightman, M.; Chen, C. T. J.; Del Moro, A.; Farrah, D.; Harrison, F. A.; Koss, M. J.; Lanz, L.; Marchesi, S.; Masini, A.; Nardini, E.; Ricci, Claudio; Stern, D.; Zappacosta, L.We present NuSTAR (Nuclear Spectroscopic Telescope Array) observations of four active galactic nuclei (AGNs) located within 15 Mpc. These AGNs, namely ESO 121-G6, NGC 660, NGC 3486, and NGC 5195, have observed X-ray luminosities of L 2–10 keV,obs ≲ 10 39 erg s −1 , classifying them as low-luminosity AGN (LLAGN). We perform broad-band X-ray spectral analysis for the AGN by combining our NuSTAR data with Chandra or XMM–Newton observations to directly measure their column densities (N H ) and infer their intrinsic power. We complement our X-ray data with archival and new high-angular resolution mid-infrared (mid-IR) data for all objects, except NGC 5195. Based on our X-ray spectral analysis, we found that both ESO 121-G6 and NGC 660 are heavily obscured (N H > 10 23 cm −2 ; L 2–10 keV,int ∼ 10 41 erg s −1 ), and NGC 660 may be Compton thick. We also note that the X-ray flux and spectral slope for ESO 121-G6 have significantly changed over the last decade, indicating significant changes in the obscuration and potentially accretion rate. On the other hand, NGC 3486 and NGC 5195 appear to be unobscured and just mildly obscured, respectively, with L 2–10 keV,int < 10 39 erg s −1 , i.e. genuine LLAGN. Both of the heavily obscured AGNs have L bol > 10 41 erg s −1 and λ Edd ≳ 10 −3 , and are detected in high-angular resolution mid-IR imaging, indicating the presence of obscuring dust on nuclear scale. NGC 3486, however, is undetected in high-resolution mid-IR imaging, and the current data do not provide stringent constraints on the presence or absence of obscuring nuclear dust in the AGN.
- ItemNuSTAR observations of water megamaser AGN(2016) Masini, A.; Comastri, A.; Baloković, M.; Zaw, I.; Puccetti, S.; Ballantyne, D. R.; Bauer, Franz Erik; Boggs, S. E.; Brandt, W. N.; Brightman, M.; Christensen, F. E.; Craig, W. W.; Gandhi, P.; Hailey, C. J.; Harrison, F. A.; Koss, M. J.; Madejski, G.; Ricci, Claudio; Rivers, E.; Stern, D.
- ItemNuSTAR Observations of WISE J1036+0449, a Galaxy at z~1 Obscured by Hot Dust.(2017) Ricci, Claudio; Bauer, Franz Erik; Treister, Ezequiel; Nikutta, R.; Assef T., Roberto; Stern, D.; Alexander, D. M.; Asmus, D.; Ballantyne, D. R.; Blain, A. W.; Boggs, Steven E.
- ItemSimultaneous NuSTAR and XMM-Newton 0.5-80 keV spectroscopy of the narrow-line Seyfert 1 galaxy SWIFT J2127.4+5654(2014) Marinucci, A.; Matt, G.; Kara, E.; Miniutti, G.; Elvis, M.; Arévalo, P.; Ballantyne, D. R.; Baloković, M.; Bauer, Franz Erik; Brenneman, L.
- ItemThe NuSTAR Extragalactic Survey : First Direct Measurements of the Greater Than Or Similar To 10 Kev X-Ray Luminosity Function For Active Galactic Nuclei At z > 0.1(2015) Aird, J.; Alexander, D. M.; Ballantyne, D. R.; Civano, F.; Moro, A. Del; Hickox, R. C.; Lansbury, G. B.; Mullaney, J. R.; Bauer, Franz Erik; Brandt, W. N.
- ItemThe NuSTAR Extragalactic Survey: Average Broadband X-Ray Spectral Properties of the NuSTAR-detected AGNs(2017) Del Moro, A.; Bauer, Franz Erik; Treister, Ezequiel; Ricci, Claudio; Alexander, D. M.; Aird, J. A.; Civano, Francesca; Mullaney, J.; Ballantyne, D. R.; Brandt, W N.; Comastri, A.
- ItemThe NuSTAR Extragalactic Surveys: Source Catalog and the Compton-thick Fraction in the UDS Field.(2018) Masini, A.; Treister, Ezequiel; Civano, Francesca; Comastri, A.; Fornasini, F.; Ballantyne, D. R.; Lansbury, George B.; Alexander, D. M.; Boorman, P.G.; Brandt, W N.
- ItemThe NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background(2016) Harrison, F. A.; Bauer, Franz Erik; Treister, Ezequiel; Aird, J. A.; Civano, Francesca; Lansbury, George B.; Mullaney, J.; Ballantyne, D. R.; Alexander, D. M.; Stern, Daniel.; Ajello, Marco
- ItemX-Ray Bolometric Corrections for Compton-thick Active Galactic Nuclei(2017) Brightman, M.; Balokovic, M.; Ballantyne, D. R.; Bauer, Franz Erik; Boorman, P.; Buchner, J.; Brandt, W. N.; Comastri, A.; Del Moro, A.; Ricci, Claudio