Steeghs, D., McClintock, J. E., Parsons, S. G. et al. (3 more authors) (2013) The Not-so-massive Black Hole in the Microquasar GRS1915+105. Astrophysical Journal, 768. 185. ISSN 0004-637X
Abstract
We present a new dynamical study of the black hole X-ray transient GRS1915+105 making use of near-infrared spectroscopy obtained with X-shooter at the Very Large Telescope. We detect a large number of donor star absorption features across a wide range of wavelengths spanning the H and K bands. Our 24 epochs covering a baseline of over 1 yr permit us to determine a new binary ephemeris including a refined orbital period of P = 33.85 ± 0.16 days. The donor star radial velocity curves deliver a significantly improved determination of the donor semi-amplitude which is both accurate (K 2 = 126 ± 1 km s–1) and robust against choice of donor star template and spectral features used. We furthermore constrain the donor star's rotational broadening to vsin i = 21 ± 4 km s–1, delivering a binary mass ratio of q = 0.042 ± 0.024. If we combine these new constraints with distance and inclination estimates derived from modeling the radio emission, a black hole mass of M BH = 10.1 ± 0.6 M ☉ is inferred, paired with an evolved mass donor of M 2 = 0.47 ± 0.27 M ☉. Our analysis suggests a more typical black hole mass for GRS1915+105 rather than the unusually high values derived in the pioneering dynamical study by Greiner et al. Our data demonstrate that high-resolution infrared spectroscopy of obscured accreting binaries can deliver dynamical mass determinations with a precision on par with optical studies.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2013 American Astronomical Society. This is an author produced version of a paper subsequently published in Astrophysical Journal. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | binaries: close; stars: individual (GRS1915+105); techniques: radial velocities; X-rays: binaries; Online-only material: color figures |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 30 Nov 2016 16:38 |
Last Modified: | 20 Mar 2018 19:53 |
Published Version: | http://dx.doi.org/10.1088/0004-637X/768/2/185 |
Status: | Published |
Publisher: | American Astronomical Society |
Refereed: | Yes |
Identification Number: | 10.1088/0004-637X/768/2/185 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:108475 |