Black Hole Spin Misalignments in Microquasars
A microquasar is a black hole X-ray binary with outflowing jets. Conventional theory predicts alignment between three axes of a microquasar system: the black hole spin axis, the jet axis, and the rotational axis of the inner disk regions. However, these axes need not be aligned to the binary orbital axis. Understanding the origin of spin-orbit misalignments is important for predicting black hole merger statistics, measuring black hole spin, and interpreting variability in X-ray binaries. I will show that the standard model of a supernova kick imparted to the natal black hole struggles to explain the >60 degree spin-orbit misalignment in the microquasar V4641 Sgr. This result has several implications related to binary star evolution, core-collapse supernovae, and black hole phenomena.