scholarly journals The First Pulse of the Extremely Bright GRB 130427A: A Test Lab for Synchrotron Shocks

Science ◽  
2013 ◽  
Vol 343 (6166) ◽  
pp. 51-54 ◽  
Author(s):  
R. Preece ◽  
J. Michael Burgess ◽  
A. von Kienlin ◽  
P. N. Bhat ◽  
M. S. Briggs ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Power Law ◽  
Time Resolution ◽  
Gamma Ray ◽  
Strongly Correlated ◽  
Initial Pulse ◽  
Gamma Ray Burst ◽  
Curvature Effects ◽  
Peak Energy ◽  
Fine Time

Gamma-ray burst (GRB) 130427A is one of the most energetic GRBs ever observed. The initial pulse up to 2.5 seconds is possibly the brightest well-isolated pulse observed to date. A fine time resolution spectral analysis shows power-law decays of the peak energy from the onset of the pulse, consistent with models of internal synchrotron shock pulses. However, a strongly correlated power-law behavior is observed between the luminosity and the spectral peak energy that is inconsistent with curvature effects arising in the relativistic outflow. It is difficult for any of the existing models to account for all of the observed spectral and temporal behaviors simultaneously.

scholarly journals Spectral analysis of GRB with the gamma–ray burst monitor on–board BeppoSAX

1999 ◽  
Vol 138 (3) ◽  
pp. 403-404 ◽  
Author(s):  
L. Amati ◽  
F. Frontera ◽  
E. Costa ◽  
M. Feroci ◽  
M. N. Cinti ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Gamma Ray ◽  
Gamma Ray Burst

scholarly journals GRB 190114C: from prompt to afterglow?

2019 ◽  
Vol 626 ◽  
pp. A12 ◽  
Author(s):  
M. E. Ravasio ◽  
G. Oganesyan ◽  
O. S. Salafia ◽  
G. Ghirlanda ◽  
G. Ghisellini ◽  
...  
Keyword(s):  
Energy Range ◽  
Power Law ◽  
Gamma Ray ◽  
Spectral Energy Distribution ◽  
Onset Time ◽  
Lorentz Factor ◽  
Spectral Energy ◽  
Large Area ◽  
Spectral Evolution ◽  
Gamma Ray Burst

GRB 190114C is the first gamma-ray burst detected at very high energies (VHE, i.e., > 300 GeV) by the MAGIC Cherenkov telescope. The analysis of the emission detected by the Fermi satellite at lower energies, in the 10 keV–100 GeV energy range, up to ∼50 s (i.e., before the MAGIC detection) can hold valuable information. We analyze the spectral evolution of the emission of GRB 190114C as detected by the Fermi Gamma-Ray Burst Monitor (GBM) in the 10 keV–40 MeV energy range up to ∼60 s. The first 4 s of the burst feature a typical prompt emission spectrum, which can be fit by a smoothly broken power-law function with typical parameters. Starting on ∼4 s post-trigger, we find an additional nonthermal component that can be fit by a power law. This component rises and decays quickly. The 10 keV–40 MeV flux of the power-law component peaks at ∼6 s; it reaches a value of 1.7 × 10−5 erg cm−2 s−1. The time of the peak coincides with the emission peak detected by the Large Area Telescope (LAT) on board Fermi. The power-law spectral slope that we find in the GBM data is remarkably similar to that of the LAT spectrum, and the GBM+LAT spectral energy distribution seems to be consistent with a single component. This suggests that the LAT emission and the power-law component that we find in the GBM data belong to the same emission component, which we interpret as due to the afterglow of the burst. The onset time allows us to estimate that the initial jet bulk Lorentz factor Γ0 is about 500, depending on the assumed circum-burst density.

scholarly journals A Bayesian Fermi-GBM short GRB spectral catalogue

2019 ◽  
Vol 490 (1) ◽  
pp. 927-946 ◽  
Author(s):  
J Michael Burgess ◽  
Jochen Greiner ◽  
Damien Bégué ◽  
Franceso Berlato
Keyword(s):  
Light Curve ◽  
Gravitational Wave ◽  
Power Law ◽  
Gamma Ray ◽  
Posterior Distributions ◽  
Time Resolved ◽  
Gamma Ray Burst ◽  
Posterior Predictive Checks ◽  
Peak Flux ◽  
Reduced Data

ABSTRACT Inspired by the confirmed detection of a short gamma-ray burst (GRB) in association with a gravitational wave signal, we present the first Bayesian Fermi-Gamma-ray Burst Monitor (GBM) short GRB spectral catalogue. Both peak flux and time-resolved spectral results are presented. Data are analysed with the proper Poisson likelihood allowing us to provide statistically reliable results even for spectra with few counts. All fits are validated with posterior predictive checks. We find that nearly all spectra can be modelled with a cut-off power law. Additionally, we release the full posterior distributions and reduced data from our sample. Following our previous study, we introduce three variability classes based on the observed light-curve structure.

scholarly journals Luminosity Distribution of Gamma-ray Burst Optical Afterglows

2012 ◽  
Vol 8 (S290) ◽  
pp. 335-336
Author(s):  
X. G. Wang ◽  
E. W. Liang ◽  
L. Li ◽  
J. J. Wei ◽  
B. Zhang
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Power Law ◽  
Luminosity Function ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Gamma Ray Burst

AbstractWe derive the optical afterglow luminosity distributions at different epoches for gamma-ray bursts (GRBs) from a sample of 146 GRBs that have a well-sampled optical afterglow lightcurve, then explore the luminosity function of GRB optical afterglows using the Monte Carlo simulation. We show that an intrinsic broken power-law luminosity function can well reproduced the observed magnitude distributions.

scholarly journals A test of the power-law relationship between gamma-ray burst pulse-width ratio and energy expected in fireballs and uniform jets

2006 ◽  
Vol 368 (3) ◽  
pp. 1351-1358 ◽  
Author(s):  
Z.-Y. Peng ◽  
Y.-P. Qin ◽  
B.-B. Zhang ◽  
R.-J. Lu ◽  
L.-W. Jia ◽  
...  
Keyword(s):  
Power Law ◽  
Pulse Width ◽  
Gamma Ray ◽  
Width Ratio ◽  
Gamma Ray Burst ◽  
Burst Pulse

scholarly journals Search for Relativistic Curvature Effects in Gamma‐Ray Burst Pulses

2003 ◽  
Vol 596 (1) ◽  
pp. 389-400 ◽  
Author(s):  
Dan Kocevski ◽  
Felix Ryde ◽  
Edison Liang
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Burst ◽  
Curvature Effects
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