Can direct collapse black holes launch gamma-ray bursts and grow to supermassive black holes?

TL;DR

This paper explores how direct collapse black holes could produce ultra-long gamma-ray bursts, potentially explaining the rapid growth of supermassive black holes in the early universe.

Contribution

It demonstrates that jets from accretion disks around direct collapse black holes can produce detectable gamma-ray bursts and influence galaxy evolution.

Findings

Ultra-long gamma-ray bursts could be detectable by Swift.

Jet breakout is possible due to the star's radiation pressure-dominated envelope.

Negative feedback from explosions can delay black hole growth by ~70 Myr.

Abstract

The existence of black holes (BHs) of mass ~ 10^{9} M_sun at z > 6 is a big puzzle in astrophysics because even optimistic estimates of the accretion time are insufficient for stellar mass BHs of ~ 10 M_sun to grow into such supermassive BHs. A resolution of this puzzle might be the direct collapse of supermassive stars with mass M ~ 10^{5} M_sun into massive seed BHs. We find that if a jet is launched from the accretion disk around the central BH, the jet can break out the star because of the structure of the radiation pressure-dominated envelope. Such ultra-long gamma-ray bursts with duration of ~ 10^{4} - 10^{6} s and flux of 10^{-11} - 10^{-8} erg s^{-1} cm^{-2} could be detectable by Swift. We estimate an event rate of < 1yr^{-1}. The total explosion energy is > 10^{55} - 10^{56} erg. The resulting negative feedback delays the growth of the remnant BH by about 70 Myr or evacuates the host galaxy completely.