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arXiv · 1301.0274

The mass of the black hole in GRS 1915+105: new constraints from IR spectroscopy

D. J. Hurley·P. J. Callanan·P. Elebert·M. T. Reynolds
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Abstract

GRS 1915+105 has the largest mass function of any Galactic black hole system, although the error is relatively large. Here we present spectroscopic analysis of medium-resolution IR VLT archival data of GRS 1915+105 in the K-band. We find an updated ephemeris, and report on attempts to improve the mass function by a refinement of the radial velocity estimate. We show that the spectra are significantly affected by the presence of phase-dependent CO bandhead emission, possibly originating from the accretion disc: we discuss the impact this has on efforts to better constrain the black hole mass. We report on a possible way to measure the radial velocity utilising apparent H-band atomic absorption features and also discuss the general uncertainty of the system parameters of this well-studied object

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D. J. Hurley, P. J. Callanan, P. Elebert, M. T. Reynolds. 2013-01-02. The mass of the black hole in GRS 1915+105: new constraints from IR spectroscopy. https://doi.org/10.1093/mnras/stt001

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