Revealing the broad iron Kα line in Cygnus X-1 through simultaneous XMM-Newton, RXTE, and INTEGRAL observations

Duro R, Dauser T, Grinberg V, Miskovicova I, Rodriguez J, Tomsick J, Hanke M, Pottschmidt K, Nowak MA, Kreykenbohm SS, Bel MC, Bodaghee A, Lohfink A, Reynolds CS, Kendziorra E, Kirsch MGF, Staubert R, Wilms J (2016)

Publication Type: Journal article, Original article

Publication year: 2016

Journal

Book Volume: 589

Article Number: A14

DOI: 10.1051/0004-6361/201424740

Abstract

We report on the analysis of the broad Fe Kα line feature of Cyg X-1 in the spectra of four simultaneous hard intermediate state observations made with the X-ray Multiple Mirror mission (XMM-Newton), the Rossi X-ray Timing Explorer (RXTE), and the International Gamma-Ray Astrophysics Laboratory (INTEGRAL). The high quality of the XMM-Newton data taken in the Modified Timing Mode of the EPIC-pn camera provides a great opportunity to investigate the broadened Fe Kα reflection line at 6.4 keV with a very high signal to noise ratio. The 4-500 keV energy range is used to constrain the underlying continuum and the reflection at higher energies. We first investigate the data by applying a phenomenological model that consists of the sum of an exponentially cutoff power law and relativistically smeared reflection. Additionally, we apply a more physical approach and model the irradiation of the accretion disk directly from the lamp post geometry. All four observations show consistent values for the black hole parameters with a spin of a ~ 0.9, in agreement with recent measurements from reflection and disk continuum fitting. The inclination is found to be i ~30°, consistent with the orbital inclination and different from inclination measurements made during the soft state, which show a higher inclination. We speculate that the difference between the inclination measurements is due to changes in the inner region of the accretion disk.

Authors with CRIS profile

Involved external institutions

Massachusetts Institute of Technology (MIT) United States (USA) (US) University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot France (FR) University of Cambridge United Kingdom (GB) University of Maryland United States (USA) (US) Eberhard Karls Universität Tübingen Germany (DE) European Space Agency (ESA) France (FR) University of California, Berkeley United States (USA) (US) Rechenzentrum Garching der Max-Planck-Gesellschaft (MPCDF) / Max Planck Computing & Data Facility Germany (DE)

How to cite

APA:

Duro, R., Dauser, T., Grinberg, V., Miskovicova, I., Rodriguez, J., Tomsick, J.,... Wilms, J. (2016). Revealing the broad iron Kα line in Cygnus X-1 through simultaneous XMM-Newton, RXTE, and INTEGRAL observations. Astronomy & Astrophysics, 589. https://doi.org/10.1051/0004-6361/201424740

MLA:

Duro, Refiz, et al. "Revealing the broad iron Kα line in Cygnus X-1 through simultaneous XMM-Newton, RXTE, and INTEGRAL observations." Astronomy & Astrophysics 589 (2016).

BibTeX: Download