scholarly journals Gamma-ray burst afterglow blast waves

2018 ◽  
Vol 27 (13) ◽  
pp. 1842002 ◽  
Author(s):  
Hendrik van Eerten
Keyword(s):  
Gamma Ray ◽  
Blast Waves ◽  
Dense Medium ◽  
X Rays ◽  
Reverse Shock ◽  
Stellar Envelope ◽  
Gamma Ray Burst ◽  
Shock System ◽  
Set Up ◽  
The Universe

The various stages of baryonic gamma-ray burst (GRB) afterglow blast waves are reviewed. These are responsible for the afterglow emission from which much of our understanding of gamma-ray bursts derives. Initially, the blast waves are confined to the dense medium surrounding the burster (stellar envelope or dense wind), giving rise to a jet-cocoon structure. A massive ejecta is released and potentially fed by ongoing energy release from the burster and a forward–reverse shock system is set up between ejecta and ambient density. Ultimately the blast wave spreads sideways and slows down, and the dominant afterglow emission shifts from X-rays down to radio. Over the past years significant progress has been made both observationally and theoretically/numerically in our understanding of these blast waves, unique in the universe due to their often incredibly high initial Lorentz factors of 100–1000. The recent discovery of a short gamma-ray burst counterpart to a gravitational wave detection (GW 170817) brings the promise of a completely new avenue to explore and constrain the dynamics of gamma-ray burst blast waves.

scholarly journals DYNAMICS AND AFTERGLOW LIGHT CURVES OF GAMMA-RAY BURST BLAST WAVES WITH A LONG-LIVED REVERSE SHOCK

2012 ◽  
Vol 761 (2) ◽  
pp. 147 ◽  
Author(s):  
Z. Lucas Uhm ◽  
Bing Zhang ◽  
Romain Hascoët ◽  
Frédéric Daigne ◽  
Robert Mochkovitch ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Blast Waves ◽  
Light Curves ◽  
Reverse Shock ◽  
Gamma Ray Burst

scholarly journals The Bright Optical Flash and Afterglow from the Gamma-Ray Burst GRB 130427A

Science ◽  
2013 ◽  
Vol 343 (6166) ◽  
pp. 38-41 ◽  
Author(s):  
W. T. Vestrand ◽  
J. A. Wren ◽  
A. Panaitescu ◽  
P. R. Wozniak ◽  
H. Davis ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Massive Stars ◽  
Close Correlation ◽  
Optical Observations ◽  
X Rays ◽  
Reverse Shock ◽  
Gamma Ray Burst ◽  
Forward Shock ◽  
Gamma Ray Emission

The optical light generated simultaneously with x-rays and gamma rays during a gamma-ray burst (GRB) provides clues about the nature of the explosions that occur as massive stars collapse. We report on the bright optical flash and fading afterglow from powerful burst GRB 130427A. The optical and >100–megaelectron volt (MeV) gamma-ray flux show a close correlation during the first 7000 seconds, which is best explained by reverse shock emission cogenerated in the relativistic burst ejecta as it collides with surrounding material. At later times, optical observations show the emergence of emission generated by a forward shock traversing the circumburst environment. The link between optical afterglow and >100-MeV emission suggests that nearby early peaked afterglows will be the best candidates for studying gamma-ray emission at energies ranging from gigaelectron volts to teraelectron volts.

scholarly journals Physical Constraints on Models of Gamma-Ray Bursters

1986 ◽  
Vol 89 ◽  
pp. 305-321
Author(s):  
Richard I. Epstein
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
X Rays ◽  
Burst Source ◽  
Gamma Ray Burst ◽  
Physical Constraints ◽  
Low Energies ◽  
Energy Gamma ◽  
Photon Interactions

AbstractThe power per logarithmic bandwidth in gamma-ray burst spectra generally increases rapidly with energy through the x-ray range and does not cut off sharply above a few MeV. This spectral form indicates that a very small fraction of the energy from a gamma-ray burst source is emitted at low energies or is reprocessed into x-rays and that the high-energy gamma rays are not destroyed by photon-photon interactions. The implications are that the emission mechanism for the gamma-ray bursts is not synchrotron radiation from electrons that lose most of their energy before being re-accelerated and that either the regions from which the gamma rays are emitted are large compared to the size of a neutron star or the emission is collimated and beamed away from the stellar surface.

Early Gamma‐Ray Burst Afterglows from Relativistic Blast Waves in General Radiative Regimes

2000 ◽  
Vol 532 (1) ◽  
pp. 281-285 ◽  
Author(s):  
Markus Bottcher ◽  
Charles D. Dermer
Keyword(s):  
Gamma Ray ◽  
Blast Waves ◽  
Gamma Ray Burst

scholarly journals X-Ray Astronomy Satellite Ginga

1990 ◽  
Vol 123 ◽  
pp. 41-48
Author(s):  
F. Makino
Keyword(s):  
Gamma Ray ◽  
Effective Area ◽  
X Rays ◽  
Scientific Instruments ◽  
Large Area ◽  
Gamma Ray Burst ◽  
X Ray ◽  
Proportional Counters ◽  
Main Instrument

AbstractThe X-ray astronomy satellite Ginga carries three scientific instruments, the Large Area proportional Counters (LAC), All Sky X-ray Monitor (ASM) and Gamma-ray Burst Detector (GBD). The LAC is the main instrument with an effective area of 4000 cm2 giving it the highest sensitivity to hard X-rays so far achieved. Ginga observed about 250 targets up to the end of 1989.

scholarly journals STATISTICAL PROPERTIES OF GRB AFTERGLOW PARAMETERS AS EVIDENCE OF COSMOLOGICAL EVOLUTION OF THEIR HOST GALAXIES

2014 ◽  
Vol 54 (4) ◽  
pp. 259-265
Author(s):  
Gregory Beskin ◽  
Gor Oganesyan ◽  
Giuseppe Greco ◽  
Sergey Karpov
Keyword(s):  
Interstellar Medium ◽  
Gamma Ray ◽  
Formation Rate ◽  
Cosmological Evolution ◽  
Gamma Activity ◽  
Host Galaxies ◽  
Reverse Shock ◽  
Gamma Ray Burst ◽  
Pair Correlations ◽  
Peak Luminosity

The results of a study of 43 peaked R-band light curves of optical counterparts of gamma-ray bursts with known redshifts are presented. The parameters of optical transients were calculated in the comoving frame, and then a search for pair correlations between them was conducted. A statistical analysis showed a strong correlation between the peak luminosity and the redshift both for pure afterglows and for events with residual gamma activity, which cannot be explained as an effect of observational selection.This suggests a cosmological evolution of the parameters of the local interstellar medium around the sources of the gamma-ray burst. In the models of forward and reverse shock waves, a relation between the density of the interstellar medium and the redshift was built for gamma-ray burst afterglows, leading to a power-law dependence of the star-formation rate at regions around GRBs on redshift with a slope of about 6.

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