ASASSN-15lh: a TDE about a maximally rotating $10^9 M_{\odot}$ black hole

Understand

We model the light curves of the novel and extremely luminous transient ASASSN-15lh at nine different frequencies, from infrared to ultra-violet photon energies, as an evolving relativistic disc produced in the aftermath of a tidal disruption event.

• Good fits to all nine light curves are simultaneously obtained when $M_{\rm acc} \simeq 0.07 M_{\odot}$ is accreted onto a black hole of mass $M \simeq 10^9 M_{\odot}$, and near maximal rotation $a/r_g = 0.99$.
• The best fit black hole mass is consistent with a number of existing estimates from galactic scaling relationships.
• If confirmed, our results represent the detection of one of the most massive rapidly spinning black holes to date, and are strong evidence for a TDE origin for ASASSN-15lh.