Статья

THE REFLECTION COMPONENT FROM CYGNUS X-1 IN THE SOFT STATE MEASURED BY<i>NuSTAR</i>AND<i>SUZAKU</i>

John A. TomsickSpace Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450, USA; [email protected]Michael A. NowakMassachusetts Institute of Technology, Kavli Institute for Astrophysics, Cambridge, MA 02139, USAM. L. ParkerInstitute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UKJ. M. MïllerDepartment of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109, USAAndy FabiánInstitute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UKFiona A. HarrisonCahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USAMatteo BachettiCNRS, Institut de Recherche en Astrophysique et Planétologie, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse cedex 4, FranceD. BarretCNRS, Institut de Recherche en Astrophysique et Planétologie, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse cedex 4, FranceSteven E. BoggsSpace Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450, USA; [email protected]Finn E. ChristensenDTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby, DenmarkWilliam W. CraigLawrence Livermore National Laboratory, Livermore, CA 94550, USAKarl FörsterCahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USAFelix FürstCahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USABrian W. GrefenstetteCahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USACharles J. HaileyColumbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USAAshley L. KingDepartment of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109, USAKristin K. MadsenCahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USAL. NatalucciIstituto Nazionale di Astrofisica, INAF-IAPS, via del Fosso del Cavaliere, I-00133 Roma, ItalyK. PottschmidtCRESST and NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771, USAR. R. RossPhysics Department, College of the Holy Cross, Worcester, MA 01610, USADaniel SternJet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USAD. J. WaltonCahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USAJ. WilmsDr. Karl-Remeis-Sternwarte and Erlangen Center for Astroparticle Physics, Sternwartestrassa 7, D-96049 Bamberg, GermanyWilliam W. ZhangNASA Goddard Space Flight Center, Greenbelt, MD 20771, USA

2013en

ABI

Аннотация

The black hole binary Cygnus X-1 was observed in late 2012 with the Nuclear Spectroscopic Telescope Array (NuSTAR) and Suzaku, providing spectral coverage over the ~1-300 keV range. The source was in the soft state with a multi-temperature blackbody, power law, and reflection components along with absorption from highly ionized material in the system. The high throughput of NuSTAR allows for a very high quality measurement of the complex iron line region as well as the rest of the reflection component. The iron line is clearly broadened and is well described by a relativistic blurring model, providing an opportunity to constrain the black hole spin. Although the spin constraint depends somewhat on which continuum model is used, we obtain ɑ_* > 0.83 for all models that provide a good description of the spectrum. However, none of our spectral fits give a disk inclination that is consistent with the most recently reported binary values for Cyg X-1. This may indicate that there is a >13° misalignment between the orbital plane and the inner accretion disk (i.e., a warped accretion disk) or that there is missing physics in the spectral models.

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Идентификаторы

DOI: 10.1088/0004-637x/780/1/78

Цитирования и источники

Цитирований: 3Использованных источников: 0

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