Nakamura, Takashi 2013

主要内容:


精彩摘抄:


文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1312.0297)

· References in the Article

· Citations to the Article (1) (Citation History)

· Refereed Citations to the Article

· Also-Read Articles (Reads History)

·

· Translate This Page

Title:		Soft X-ray Extended Emissions of Short Gamma-Ray Bursts as Electromagnetic Counterparts of Compact Binary Mergers; Possible Origin and Detectability
Authors:		Nakamura, Takashi; Kashiyama, Kazumi; Nakauchi, Daisuke; Suwa, Yudai; Sakamoto, Takanori; Kawai, Nobuyuki
Publication:		eprint arXiv:1312.0297
Publication Date:		12/2013
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Comment:		12 pages, 4 figures
Bibliographic Code:		2013arXiv1312.0297N

Abstract

We investigate the possible origin of extended emissions (EE) of short gamma-ray bursts (SGRBs) with an isotropic energy of $\sim 10^{50\mbox{-}51} \ \rm erg$ and a duration of $\sim 100 \ \rm s$, based on the compact binary (neutron star (NS)-NS or NS-black hole (BH)) merger scenario. We analyze the evolution of magnetized neutrino-dominated accretion disks of mass $\sim 0.1 \ M_\odot$ around BHs formed after the mergers, and estimate the power of relativistic outflows via the Blandford-Znajek (BZ) process. We show that a rotation energy of the BH up to $\sim 10^{53} \ \rm erg$ can be extracted with a time scale of $\sim 100 \ \rm s$ with a disk viscosity parameter of $\alpha \sim 0.01$. Such a BZ power dissipates by clashing with non-relativistic pre-ejected matter of mass $M \sim 10^{-(2\mbox{-}4)} \ M_\odot$, and form a mildly relativistic fireball. We show that the dissipative photospheric emissions from such fireballs are likely in soft X-ray band ($1\mbox{-}10 \ \rm keV$) for $M \sim 10^{-2} M_\odot$ possibly in NS-NS mergers, and in the BAT band ($15\mbox{-}150 \ \rm keV$) for $M \sim 10^{-4} M_\odot$ possibly in NS-BH mergers. In the former case, such soft EEs can provide a good chance of $\sim {\rm 6 \ yr^{-1}} \ (\Delta \Omega_{softEE}/4\pi) \ ({\cal R}_{GW}/40 \ {\rm yr^{-1}})$ for simultaneous detections of the gravitational waves with a $\sim 0.1^\circ$ angular resolution by soft X-ray survey facilities like Wide-Field MAXI. Here, $\Delta \Omega_{softEE}$ is the beaming factor of the soft EEs and ${\cal R}_{GW}$ is the NS-NS merger rate detectable by advanced LIGO, advanced Virgo, and KAGRA. While in the latter case, the observed EEs, which are associated with $\sim 25\%$ of {\it Swift} SGRBs, can be well explained although the simultaneous detection rate with the GWs is expected to be very low $\lesssim 10^{-3} \ {\rm yr}^{-1} $.

---

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)