2008MNRAS.391L..15M

In the microquasar V4641 Sgr, the spin of the black hole is thought to be misaligned with the binary orbital axis. The accretion disc aligns with the black hole spin by the Lense-Thirring effect near to the black hole and further out becomes aligned with the binary orbital axis. The inclination of the radio jets and the Fe Kα line profile have both been used to determine the inclination of the inner accretion disc but the measurements are inconsistent. Using a steady-state analytical-warped disc model for V4641 Sgr, we find that the inner disc region is flat and aligned with the black hole up to about 900R_g. Thus, if both the radio jet and fluorescent emission originate in the same inner region then the measurements of the inner disc inclination should be the same.