Giant X-ray Bump in GRB 121027A: Evidence for Fall-back Disk Accretion
arXiv:1302.4878 · doi:10.1088/2041-8205/767/2/L36
Abstract
A particularly interesting discovery in observations of GRB 121027A is that of a giant X-ray bump detected by the Swift/X-Ray Telescope. The X-ray afterglow re-brightens sharply at about 1000 s after the trigger by more than two orders of magnitude in less than 200 s. This X-ray bump lasts for more than 10 ks. It is quite different from typical X-ray flares. In this Letter we propose a fall-back accretion model to interpret this X-ray bump within the context of the collapse of a massive star for a long-duration gamma-ray burst. The required fall-back radius of about 3.5e10 cm and mass of about 0.9-2.6 solar masses imply that a significant part of the helium envelope should survive through the mass loss during the last stage of the massive progenitor of GRB 121027A.
5 pages, 3 figures, 2013, ApJL, 767:L36
References in corpus (11)
- An online repository of Swift/XRT light curves of GRBs
- The Internal-Collision-Induced Magnetic Reconnection and Turbulence (ICMART) Model of Gamma-Ray Bursts
- Neutrino-Cooled Accretion Disks around Spinning Black Hole
- Fallback and Black Hole Production in Massive Stars
- Mass Fall-back and Accretion in the Central Engine of Gamma-Ray Bursts
- Hyper-accreting black hole as GRB central engine. I: Baryon loading in GRB jets
- Neutrino-Dominated Accretion Models for Gamma-Ray Bursts: Effects of General Relativity and Neutrino Opacity
- Properties of Gamma-Ray Burst Progenitor Stars
- Instabilities in the time-dependent neutrino disc in Gamma-Ray Bursts
- Magnetically Torqued Neutrino-Dominated Accretion Flows for Gamma-ray Bursts
- Development of General Relativistic Magnetohydrodynamic Code and its Application to Central Engine of Long Gamma-Ray Bursts