The mass of the black hole in LMC X-3

Val-Baker, A. K. F.; Norton, A. J. and Negueruela, I. (2007). The mass of the black hole in LMC X-3. In: The Multicoloured Landscape of Compact Objects and their Explosive Origins: Theory vs. Observations, 18-24 Jun 2006, Cefalu, Sicily, Italy.

DOI: https://doi.org/10.1063/1.2774906

Abstract

New high resolution, optical spectroscopy of the high mass X-ray binary LMC X-3, shows the spectral type of the donor star changes with phase due to irradition by the X-ray source. We find the spectral type is likely to be B5V, and only appears as B3V when viewing the heated side of the donor. Combining our measurements with those previously published, and taking into account the effects of X-ray irradiation, results in a value for the donor star radial velocity semi-amplitude of $K_{o} = 256.7 \pm 4.9$ ~km~s $^{-1}$ . We find the mass of the black hole lies in the range $9.5M_{\odot} \leq M_{\rm x} \leq 13.6M_{\odot}$ .