Hypervelocity Stars from a Supermassive Black Hole-Intermediate-mass Black Hole binary

Understand

In this paper we consider a scenario where the currently observed hypervelocity stars in our Galaxy have been ejected from the Galactic center as a result of dynamical interactions with an intermediate-mass black hole (IMBH) orbiting the central supermassive black hole (SMBH).

• By performing 3-body scattering experiments, we calculate the distribution of the ejected stars' velocities given various parameters of the IMBH-SMBH binary: IMBH mass, semimajor axis and eccentricity.
• We also calculate the rates of change of the BH binary orbital elements due to those stellar ejections.
• One of our new findings is that the ejection rate depends (although mildly) on the rotation of the stellar nucleus (its total angular momentum).