scholarly journals SOFT X-RAY EXTENDED EMISSIONS OF SHORT GAMMA-RAY BURSTS AS ELECTROMAGNETIC COUNTERPARTS OF COMPACT BINARY MERGERS: POSSIBLE ORIGIN AND DETECTABILITY

2014 ◽  
Vol 796 (1) ◽  
pp. 13 ◽  
Author(s):  
Takashi Nakamura ◽  
Kazumi Kashiyama ◽  
Daisuke Nakauchi ◽  
Yudai Suwa ◽  
Takanori Sakamoto ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
X Ray ◽  
Compact Binary ◽  
Binary Mergers

scholarly journals Gamma-ray Bursts Progress and Problems

2016 ◽  
Vol 12 (S324) ◽  
pp. 49-53
Author(s):  
N. R. Tanvir
Keyword(s):  
Galaxy Evolution ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Compact Binary ◽  
Distant Galaxies ◽  
Long Duration ◽  
Massive Neutron Star ◽  
Binary Mergers ◽  
The Impact ◽  
The Universe

AbstractOur understanding of gamma-ray bursts (GRBs) has come a long way in the past fifty years since their first detection. We now know that GRBs arise in distant galaxies and that there are at least two distinct sub-classes, the long-duration class being produced by some rare massive star core collapse and the short-duration class likely by compact binary mergers involved neutron stars. In both cases, the final remnant will be a stellar-mass black-hole or a massive neutron star. The bursts themselves are associated with ultra-relativistic jetted outflows created by these events, and their afterglows by the impact of these outflows on the surrounding circumburst material. Increasingly GRBs are also being used as probes of the universe, both for understanding galaxy evolution back to the era of reionization, and for the physics of gravitational wave sources. However, many aspects of GRBs remain poorly understood, some pointers to which are given here.

scholarly journals Precessing magnetars as central engines in short gamma-ray bursts

2021 ◽  
Vol 502 (2) ◽  
pp. 2482-2494
Author(s):  
A G Suvorov ◽  
K D Kokkotas
Keyword(s):  
Gamma Ray ◽  
Magnetic Energy ◽  
Information Criterion ◽  
Gamma Ray Bursts ◽  
Internal Stresses ◽  
X Ray ◽  
Compact Binary ◽  
Long Duration ◽  
Hydrodynamic Evolution ◽  
Data Points

ABSTRACT Short gamma-ray bursts that are followed by long-duration X-ray plateaus may be powered by the birth, and hydrodynamic evolution, of magnetars from compact binary coalescence events. If the rotation and magnetic axes of the system are not orthogonal to each other, the star will undergo free precession, leading to fluctuations in the luminosity of the source. In some cases, precession-induced modulations in the spin-down power may be discernible in the X-ray flux of the plateau. In this work, 25 X-ray light curves associated with bursts exhibiting a plateau are fitted to luminosity profiles appropriate for precessing, oblique rotators. Based on the Akaike Information Criterion, 16 $(64{{\ \rm per\ cent}})$ of the magnetars within the sample display either moderate or strong evidence for precession. Additionally, since the precession period of the star is directly tied to its quadrupolar ellipticity, the fits allow for an independent measure of the extent to which the star is deformed by internal stresses. Assuming these deformations arise due to a mixed poloidal–toroidal magnetic field, we find that the distribution of magnetic-energy ratios is bimodal, with data points clustering around energetically equal and toroidally dominated partitions. Implications of this result for gravitational-wave emission and dynamo activity in newborn magnetars are discussed.

scholarly journals Gamma-ray bursts associating with gravitational waves from compact binary mergers

2020 ◽  
Vol 50 (12) ◽  
pp. 129502
Author(s):  
TAN Wei-Wei ◽  
YU Yun-Wei ◽  
DAI Zi-Gao ◽  
LI Yong-Sen
Keyword(s):  
Gravitational Waves ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Compact Binary ◽  
Binary Mergers

Short gamma-ray bursts near and far

2007 ◽  
Vol 365 (1854) ◽  
pp. 1315-1321 ◽  
Author(s):  
Andrew J Levan
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Compact Binary ◽  
Binary Mergers ◽  
Short Grbs

Progress in understanding the nature of short gamma-ray bursts (GRBs) has been rapid since the discovery of the first afterglows in mid-2005. The emerging picture appears to be of short GRBs, which originate at moderate redshift (a few tenths) and appear in galaxies of all ages. This discovery has been used to argue for their origin in compact binary mergers. However, this population does not describe all short bursts. Here, I will present results of observations of several short GRBs, which challenge the conclusions drawn from the early observations. The observations show that some short GRBs originate in the very low redshift Universe (below 100 Mpc), while some may also lie at redshifts comparable with the long GRBs (i.e. z >2). I will discuss the properties of these bursts and the implications they have for the progenitors of short GRBs.

scholarly journals Intracluster Short Gamma-Ray Bursts by Compact Binary Mergers

2008 ◽  
Vol 677 (1) ◽  
pp. L23-L26 ◽  
Author(s):  
Yuu Niino ◽  
Tomonori Totani
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Compact Binary ◽  
Binary Mergers

The X-ray luminosity function of short gamma-ray bursts

2021 ◽  
Vol 366 (4) ◽  
Author(s):  
Zhi-Ying Liu ◽  
Fu-Wen Zhang ◽  
Si-Yuan Zhu
Keyword(s):  
Luminosity Function ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
X Ray

scholarly journals Interpreting the X-ray afterglows of gamma-ray bursts with radiative losses and millisecond magnetars

2020 ◽  
Vol 499 (4) ◽  
pp. 5986-5992
Author(s):  
Nikhil Sarin ◽  
Paul D Lasky ◽  
Gregory Ashton
Keyword(s):  
Gravitational Wave ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Dipole Radiation ◽  
X Ray ◽  
Radiative Efficiency ◽  
Central Engine ◽  
Radiative Losses ◽  
Wave Emission ◽  
Prompt Emission

ABSTRACT The spin-down energy of millisecond magnetars has been invoked to explain X-ray afterglow observations of a significant fraction of short and long gamma-ray bursts. Here, we extend models previously introduced in the literature, incorporating radiative losses with the spin-down of a magnetar central engine through an arbitrary braking index. Combining this with a model for the tail of the prompt emission, we show that our model can better explain the data than millisecond-magnetar models without radiative losses or those that invoke spin-down solely through vacuum dipole radiation. We find that our model predicts a subset of X-ray flares seen in some gamma-ray bursts. We can further explain the diversity of X-ray plateaus by altering the radiative efficiency and measure the braking index of newly born millisecond magnetars. We measure the braking index of GRB061121 as $n=4.85^{+0.11}_{-0.15}$ suggesting the millisecond-magnetar born in this gamma-ray burst spins down predominantly through gravitational-wave emission.

Sign in / Sign up

Export Citation Format

Share Document