A refined dynamical mass for the black hole in the X-ray transient XTE J1859+226
A refined dynamical mass for the black hole in the X-ray transient XTE J1859+226
ABSTRACT We present two contiguous nights of simultaneous time-resolved Gran Telescopio Canarias spectroscopy and William Herschel Telescope photometry of the black hole X-ray transient XTE J1859+226, obtained in 2017 July during quiescence. Cross-correlation of the individual spectra against a late K-type spectral template enabled us to constrain the orbital period …