CAN DIRECT COLLAPSE BLACK HOLES LAUNCH GAMMA-RAY BURSTS AND GROW TO SUPERMASSIVE BLACK HOLES?

The existence of black holes (BHs) of mass similar to 10(9) M-circle dot at Z greater than or similar to 6 is a big puzzle in astrophysics because even optimistic estimates of the accretion time are insufficient for stellar-mass BHs of similar to 10 M-circle dot to grow into such supermassive BHs. A resolution of this puzzle might be the direct collapse of supermassive stars with mass M 105Mo 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 of the star because of the structure of the radiation-pressure-dominated envelope. Such ultralong gamma-ray bursts with duration of similar to 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 less than or similar to 1 yr(-1). The total explosion energy is greater than or similar to 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.