The effects of high density on the X-ray spectrum reflected from accretion discs around black holes

Garcia JA, Fabian AC, Kallman TR, Dauser T, Parker ML, Mcclintock JE, Steiner JF, Wilms J (2016)

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2016

Journal

Monthly Notices of the Royal Astronomical Society Oxford University Press

Publisher: Oxford University Press

Book Volume: 462

Pages Range: 751-760

Article Number: stw1696

Journal Issue: 1

DOI: 10.1093/mnras/stw1696

Abstract

Current models of the spectrum of X-rays reflected from accretion discs around black holes and other compact objects are commonly calculated assuming that the density of the disc atmosphere is constant within several Thomson depths from the irradiated surface. An important simplifying assumption of these models is that the ionization structure of the gas is completely specified by a single, fixed value of the ionization parameter ξ, which is the ratio of the incident flux to the gas density. The density is typically fixed at ne = 10 cm. Motivated by observations, we consider higher densities in the calculation of the reflected spectrum. We show by computing model spectra for ne ≥ 10 cm that high-density effects significantly modify reflection spectra. The main effect is to boost the thermal continuum at energies ≥2 keV. We discuss the implications of these results for interpreting observations of both active galactic nuclei and black hole binaries. We also discuss the limitations of our models imposed by the quality of the atomic data currently available.

Authors with CRIS profile

Thomas Dauser Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut Jörn Wilms Professur für Astronomie und Astrophysik

Involved external institutions

Massachusetts Institute of Technology (MIT) US United States (USA) (US) National Aeronautics and Space Administration (NASA) US United States (USA) (US) University of Cambridge GB United Kingdom (GB) Harvard University US United States (USA) (US)

How to cite

APA:

Garcia, J.A., Fabian, A.C., Kallman, T.R., Dauser, T., Parker, M.L., Mcclintock, J.E.,... Wilms, J. (2016). The effects of high density on the X-ray spectrum reflected from accretion discs around black holes. Monthly Notices of the Royal Astronomical Society, 462(1), 751-760. https://doi.org/10.1093/mnras/stw1696

MLA:

Garcia, Javier A., et al. "The effects of high density on the X-ray spectrum reflected from accretion discs around black holes." Monthly Notices of the Royal Astronomical Society 462.1 (2016): 751-760.

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