STELLAR TIDAL DISRUPTION EVENTS BY DIRECT-COLLAPSE BLACK HOLES

Kazumi Kashiyama, Kohei Inayoshi
2016 Astrophysical Journal  
We analyze the early growth stage of direct-collapse black holes (DCBHs) with ∼ 10^5 M_, which are formed by collapse of supermassive stars in atomic-cooling halos at z ≳ 10. A nuclear accretion disk around a newborn DCBH is gravitationally unstable and fragments into clumps with a few 10 M_ at ∼ 0.01-0.1 pc from the center. Such clumps evolve into massive population III stars with a few 10-100 M_ via successive gas accretion and a nuclear star cluster is formed. Radiative and mechanical
more » ... k from an inner slim disk and the star cluster will significantly reduce the gas accretion rate onto the DCBH within ∼ 10^6 yr. Some of the nuclear stars can be scattered onto the loss cone orbits also within ≲ 10^6 yr and tidally disrupted by the central DCBH. The jet luminosity powered by such tidal disruption events can be L_ j≳ 10^50 erg s^-1. The prompt emission will be observed in X-ray bands with a peak duration of δ t_ obs∼ 10^5-6 (1+z) s followed by a tail ∝ t_ obs^-5/3, which can be detectable by Swift BAT and eROSITA even from z ∼ 20. Follow-up observations of the radio afterglows with, e.g., eVLA and the host halos with JWST could probe the earliest AGN feedback from DCBHs.
doi:10.3847/0004-637x/826/1/80 fatcat:4txttahl75emlbmogxshnmauc4