scholarly journals On the Intrinsic Simplicity of Spectral Variability of GRBs

10.14311/1322 ◽  
2011 ◽  
Vol 51 (1) ◽  
Author(s):  
A. Chernenko
Keyword(s):  
Correlation Analysis ◽  
Physical Parameter ◽  
Spectral Properties ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Light Curves ◽  
Spectral Variability ◽  
Time Intervals ◽  
Multi Scale

In this paper we present a Multi-Scale Correlation Analysis (MSCA) of the light curves of gamma-ray bursts recorded in different energy ranges. This analysis allows us to identify time intervals where emission variability can be reduced to a single physical parameter and can therefore be robustly attributed to a single physical emitter. The properties of these intervals can then be investigated separately, and the spectral properties of individual emitters can be analysed. The signatures of hidden dynamical relations between individual emitters are also discussed.

Can Precessing Jets Explain the Light Curves of Gamma‐Ray Bursts?

1999 ◽  
Vol 520 (2) ◽  
pp. 666-679 ◽  
Author(s):  
Simon F. Portegies Zwart ◽  
Chang‐Hwan Lee ◽  
Hyun Kyu Lee
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Light Curves

scholarly journals Constraints on the circumburst environments of short gamma-ray bursts

2020 ◽  
Vol 495 (4) ◽  
pp. 4782-4799 ◽  
Author(s):  
Brendan O’Connor ◽  
Paz Beniamini ◽  
Chryssa Kouveliotou
Keyword(s):  
Gamma Ray ◽  
Galactic Halo ◽  
Gamma Ray Bursts ◽  
Light Curves ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Binary Neutron Star ◽  
Range Of Values ◽  
Short Grbs

ABSTRACT Observational follow up of well localized short gamma-ray bursts (SGRBs) has left $20\!-\!30{{\ \rm per\ cent}}$ of the population without a coincident host galaxy association to deep optical and NIR limits (≳26 mag). These SGRBs have been classified as observationally hostless due to their lack of strong host associations. It has been argued that these hostless SGRBs could be an indication of the large distances traversed by the binary neutron star system (due to natal kicks) between its formation and its merger (leading to an SGRB). The distances of GRBs from their host galaxies can be indirectly probed by the surrounding circumburst densities. We show that a lower limit on those densities can be obtained from early afterglow light curves. We find that ${\lesssim}16{{\ \rm per\ cent}}$ of short GRBs in our sample took place at densities ≲10−4 cm−3. These densities represent the expected range of values at distances greater than the host galaxy’s virial radii. We find that out of the five SGRBs in our sample that have been found to be observationally hostless, none are consistent with having occurred beyond the virial radius of their birth galaxies. This implies one of two scenarios. Either these observationally hostless SGRBs occurred outside of the half-light radius of their host galaxy, but well within the galactic halo, or in host galaxies at moderate to high redshifts (z ≳ 2) that were missed by follow-up observations.

Precursors of short gamma-ray bursts detected by the INTEGRAL observatory

2018 ◽  
Vol 27 (10) ◽  
pp. 1844013 ◽  
Author(s):  
Pavel Minaev ◽  
Alexei Pozanenko ◽  
Sergei Molkov
Keyword(s):  
Statistical Analysis ◽  
Light Curve ◽  
Relative Intensity ◽  
Gamma Ray ◽  
Convincing Evidence ◽  
Gamma Ray Bursts ◽  
Light Curves ◽  
Upper Limits ◽  
Short Grbs

We have analyzed the light curves of 527 short gamma-ray bursts (GRBs) registered by the SPI-ACS, SPI and IBIS/ISGRI experiments of INTEGRAL observatory totally to search for precursors. Both the light curves of each 527 individual burst and the averaged light curve of 372 brightest SPI-ACS bursts have been analyzed. In a few cases, we have found and investigated precursor candidates using SPI-ACS, SPI and IBIS/ISGRI of INTEGRAL, GBM and LAT of Fermi data. No convincing evidence for the existence of precursors of short GRBs has been found. A statistical analysis of the averaged light curve for the sample of brightest short bursts has revealed no regular precursor. Upper limits for the relative intensity of precursors have been estimated. We show that the fraction of short GRBs with precursors is less than 0.4% of all short bursts, detected by INTEGRAL.

X‐Ray Light Curves of Gamma‐Ray Bursts Detected with the All‐Sky Monitor on RXTE

2002 ◽  
Vol 141 (2) ◽  
pp. 415-428 ◽  
Author(s):  
D. A. Smith ◽  
A. Levine ◽  
H. Bradt ◽  
K. Hurley ◽  
M. Feroci ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Light Curves ◽  
X Ray ◽  
Sky Monitor

scholarly journals Spectral properties of gamma-ray bursts observed by the Suzaku wide-band all-sky monitor

2019 ◽  
Vol 71 (4) ◽  
Author(s):  
Norisuke Ohmori ◽  
Kazutaka Yamaoka ◽  
Makoto Yamauchi ◽  
Yuji Urata ◽  
Masanori Ohno ◽  
...  
Keyword(s):  
Short Duration ◽  
Power Law ◽  
Spectral Properties ◽  
Gamma Ray ◽  
Wide Band ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Sky Monitor ◽  
S Peak ◽  
Single Power

Abstract We have systematically studied the spectral properties of 302 localized gamma-ray bursts (GRBs) observed by the Suzaku wide-band all-sky monitor (WAM) from 2005 August to 2010 December. The energy spectra in the 100–5000 keV range integrated over the entire emission and the 1 s peak were fitted by three models: a single power law, a power law with an exponential cutoff (CPL), and the GRB Band function (GRB). Most of the burst spectra were well fitted by a single power law. The average photon index α was −2.11 and −1.73 for long and short bursts, respectively. For the CPL and GRB models, the low-energy and high-energy photon indices (α and β) for the entire emission spectra were consistent with previous measurements. The averages of the α and β were −0.90 and −2.65 for long-duration GRBs, while the average α was −0.55 and the β was not well constrained for short-duration GRBs. However, the average peak energy Epeak was 645 and 1286 keV for long- and short-duration GRBs respectively, which are higher than previous Fermi/GBM measurements (285 keV and 736 keV). The α and Epeak of the 1 s peak spectra were larger, i.e., the spectra were harder, than the total fluence spectra. Spectral simulations based on Fermi-GBM results suggest that the higher Epeaks measured by the Suzaku WAM could be due to detector selection bias, mainly caused by the limited energy range above 100 keV.

scholarly journals Clustering of LAT light curves: a clue to the origin of high-energy emission in gamma-ray bursts

2014 ◽  
Vol 443 (4) ◽  
pp. 3578-3585 ◽  
Author(s):  
L. Nava ◽  
G. Vianello ◽  
N. Omodei ◽  
G. Ghisellini ◽  
G. Ghirlanda ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Light Curves ◽  
Energy Emission ◽  
High Energy Emission

THE CASE FOR NON-BARYONIC ENERGY AS THE PRIMARY OUTPUT OF GRBs

2008 ◽  
Vol 17 (09) ◽  
pp. 1333-1341
Author(s):  
D. EICHLER
Keyword(s):  
Kinetic Energy ◽  
Photon Energy ◽  
Radiation Pressure ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Light Curves ◽  
Poynting Flux ◽  
Primary Output ◽  
Primary Form

The evidence is reviewed that the primary form of energy that escapes to infinity from gamma-ray bursts (GRBs) is gamma-rays, and/or Poynting flux, and that the kinetic energy in ultrarelativistic baryons is a secondary component resulting from acceleration of baryons by radiation pressure near or beyond the photosphere. This could account for several observed characteristics of observed GRB spectra and light curves, such as the typical peak photon energy, the correlation of this peak with apparent GRB energy, and the profiles and spectral lagging of GRB subpulses.

Energy Injection Episodes in Gamma-Ray Bursts: The Light Curves and Polarization Properties of GRB 021004

2004 ◽  
Vol 615 (2) ◽  
pp. L77-L80 ◽  
Author(s):  
G. Björnsson ◽  
E. H. Gudmundsson ◽  
G. Jóhannesson
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Light Curves
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