Extreme black hole spin--orbit misalignment in X-ray binary MAXI J1820+070

by Alexandra Veledina (Nordita)

Wednesday 9 Mar 2022, 13:30 → 14:30 Europe/Stockholm

https://stockholmuniversity.zoom.us/j/530682073

The observational appearance of black holes in X-ray binary systems depends on their masses, spins, accretion rate and the misalignment angle between the black hole spin and the orbital angular momentum. We used high-precision optical polarimetric observations to constrain the position angle of the orbital axis of the black hole X-ray binary MAXI J1820+070. Together with previously obtained orientation of the relativistic jet and the inclination of the orbit this allowed us to determine a lower limit of 40 degrees on the misalignment angle. Such a large misalignment challenges the models of quasi-periodic oscillations observed in black hole X-ray binaries, puts strong constraints on the black hole formation mechanisms, and has to be accounted for when measuring black hole masses and spins from the X-ray data.

https://arxiv.org/abs/2109.07511

Veledina_2022-Mar-09.mp4