The role of the reflection fraction in constraining black hole spin

Dauser T, Garcia J, Parker ML, Fabian AC, Wilms J (2014)


Publication Status: Published

Publication Type: Journal article

Publication year: 2014

Journal

Publisher: OXFORD UNIV PRESS

Book Volume: 444

Pages Range: L100-L104

Journal Issue: 1

DOI: 10.1093/mnrasl/slu125

Abstract

In many active galaxies, the X-ray reflection features from the innermost regions of the accretion disc are relativistically distorted. This distortion allows us to measure parameters of the black hole such as its spin. The ratio in flux between the direct and the reflected radiation, the so-called reflection fraction, is determined directly from the geometry and location of primary source of radiation. We calculate the reflection fraction in the lamp post geometry in order to determine its maximal possible value for a given value of black hole spin. We show that high reflection fractions in excess of two are only possible for rapidly rotating black holes, suggesting that the high spin sources produce the strongest relativistic reflection features. Using simulations we show that taking this constraint into account does significantly improve the determination of the spin values. We make software routines for the most popular X-ray data analysis packages available that incorporate these additional constraints.

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APA:

Dauser, T., Garcia, J., Parker, M.L., Fabian, A.C., & Wilms, J. (2014). The role of the reflection fraction in constraining black hole spin. Monthly Notices of the Royal Astronomical Society, 444(1), L100-L104. https://doi.org/10.1093/mnrasl/slu125

MLA:

Dauser, Thomas, et al. "The role of the reflection fraction in constraining black hole spin." Monthly Notices of the Royal Astronomical Society 444.1 (2014): L100-L104.

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