scholarly journals Plasmas in Gamma-Ray Bursts: Particle Acceleration, Magnetic Fields, Radiative Processes and Environments

Galaxies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 33
Author(s):  
Asaf Pe’er
Keyword(s):  
Particle Acceleration ◽  
Magnetic Fields ◽  
Light Curve ◽  
Gamma Ray ◽  
Broad Band ◽  
Gamma Ray Bursts ◽  
Magnetic Field Generation ◽  
Radiative Processes ◽  
Physical Problems ◽  
The One

Being the most extreme explosions in the universe, gamma-ray bursts (GRBs) provide a unique laboratory to study various plasma physics phenomena. The complex light curve and broad-band, non-thermal spectra indicate a very complicated system on the one hand, but, on the other hand, provide a wealth of information to study it. In this chapter, I focus on recent progress in some of the key unsolved physical problems. These include: (1) particle acceleration and magnetic field generation in shock waves; (2) possible role of strong magnetic fields in accelerating the plasmas, and accelerating particles via the magnetic reconnection process; (3) various radiative processes that shape the observed light curve and spectra, both during the prompt and the afterglow phases, and finally (4) GRB environments and their possible observational signature.

scholarly journals Particle Acceleration in Gamma-Ray Bursts

2005 ◽  
Vol 192 ◽  
pp. 475-482
Author(s):  
J.G. Kirk
Keyword(s):  
Magnetic Field ◽  
Particle Acceleration ◽  
Shock Front ◽  
Gamma Ray ◽  
Crab Nebula ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Magnetic Field Generation ◽  
Relativistic Shocks ◽  
The Crab Nebula

SummarySimple kinematic theories of particle acceleration at relativistic shocks lead to the prediction of a high-energy spectral index of −1.1 for the energy flux of synchrotron photons. However, several effects can change this picture. In this paper I discuss the effect of magnetic field generation at the shock front and, by analogy with the Crab Nebula, suggest that an intrinsic break in the injection spectrum should be expected where the electron gyro radius is comparable to that of protons thermalized by the shock.

scholarly journals Luminous supernovae associated with ultra-long gamma-ray bursts from hydrogen-free progenitors extended by pulsational pair-instability

2020 ◽  
Vol 641 ◽  
pp. L10
Author(s):  
Takashi J. Moriya ◽  
Pablo Marchant ◽  
Sergei I. Blinnikov
Keyword(s):  
Light Curve ◽  
Energy Input ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Core Collapse ◽  
Decay Energy ◽  
Slow Cooling ◽  
Gamma Ray Burst ◽  
The Core ◽  
Optical Light Curve

We show that the luminous supernovae associated with ultra-long gamma-ray bursts can be related to the slow cooling from the explosions of hydrogen-free progenitors that are extended by pulsational pair-instability. We have recently shown that some rapidly-rotating hydrogen-free gamma-ray burst progenitors that experience pulsational pair-instability can keep an extended structure caused by pulsational pair-instability until the core collapse. These types of progenitors have large radii exceeding 10 R⊙ and they sometimes reach beyond 1000 R⊙ at the time of the core collapse. They are, therefore, promising progenitors of ultra-long gamma-ray bursts. Here, we perform light-curve modeling of the explosions of one extended hydrogen-free progenitor with a radius of 1962 R⊙. The progenitor mass is 50 M⊙ and 5 M⊙ exists in the extended envelope. We use the one-dimensional radiation hydrodynamics code STELLA in which the explosions are initiated artificially by setting given explosion energy and 56Ni mass. Thanks to the large progenitor radius, the ejecta experience slow cooling after the shock breakout and they become rapidly evolving (≲10 days), luminous (≳1043 erg s−1) supernovae in the optical even without energy input from the 56Ni nuclear decay when the explosion energy is more than 1052 erg. The 56Ni decay energy input can affect the light curves after the optical light-curve peak and make the light-curve decay slowly when the 56Ni mass is around 1 M⊙. They also have a fast photospheric velocity above 10 000 km s−1 and a hot photospheric temperature above 10 000 K at around the peak luminosity. We find that the rapid rise and luminous peak found in the optical light curve of SN 2011kl, which is associated with the ultra-long gamma-ray burst GRB 111209A, can be explained as the cooling phase of the extended progenitor. The subsequent slow light-curve decline can be related to the 56Ni decay energy input. The ultra-long gamma-ray burst progenitors we proposed recently can explain both the ultra-long gamma-ray burst duration and the accompanying supernova properties. When the gamma-ray burst jet is off-axis or choked, the luminous supernovae could be observed as fast blue optical transients without accompanying gamma-ray bursts.

scholarly journals Gamma-Ray Bursts as Sources of Strong Magnetic Fields

2016 ◽  
pp. 481-528
Author(s):  
Jonathan Granot ◽  
Tsvi Piran ◽  
Omer Bromberg ◽  
Judith L. Racusin ◽  
Frédéric Daigne
Keyword(s):  
Magnetic Fields ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Strong Magnetic Fields

Broadband Light Curve Characteristics of Two Prototypical Low-Luminosity Gamma-Ray Bursts

2008 ◽  
Author(s):  
Fu-Wen Zhang ◽  
Yong-Feng Huang ◽  
Zi-Gao Dai ◽  
Bing Zhang
Keyword(s):  
Light Curve ◽  
Gamma Ray ◽  
Gamma Ray Bursts

scholarly journals Gamma-Ray Bursts and Binary Neutron Star Mergers

1996 ◽  
Vol 165 ◽  
pp. 489-502
Author(s):  
Tsvi Piran
Keyword(s):  
Neutron Star ◽  
Gravitational Radiation ◽  
Gamma Ray ◽  
Indirect Evidence ◽  
Gamma Ray Bursts ◽  
Binary Neutron Star ◽  
Merger Event ◽  
Γ Rays ◽  
Γ Ray ◽  
The One

Neutron star binaries, such as the one observed in the famous binary pulsar PSR 1913+16, end their life in a catastrophic merger event (denoted here NS2M). The merger releases ∼5 1053 ergs, mostly as neutrinos and gravitational radiation. A small fraction of this energy suffices to power γ-ray bursts (GRBs) at cosmological distances. Cosmological GRBs must pass, however, an optically thick fireball phase and the observed γ rays emerge only at the end of this phase. Hence, it is difficult to determine the nature of the source from present observations (the agreement between the rates of GRBs and NS2Ms providing only indirect evidence for this model). In the future a coinciding detection of a GRB and a gravitational-radiation signal could confirm this model.

Gamma-Ray Bursts and Magnetic Fields

2008 ◽  
Author(s):  
Shiho Kobayashi ◽  
Yong-Feng Huang ◽  
Zi-Gao Dai ◽  
Bing Zhang
Keyword(s):  
Magnetic Fields ◽  
Gamma Ray ◽  
Gamma Ray Bursts

scholarly journals Acceleration Processes for Gamma-Ray Bursts

1994 ◽  
Vol 142 ◽  
pp. 869-876 ◽  
Author(s):  
Igor G. Mitrofanov
Keyword(s):  
Particle Acceleration ◽  
Electric Field ◽  
Neutron Stars ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Initial Energy ◽  
Gamma Ray Bursts ◽  
Acceleration Of Particles ◽  
Radiation Mechanisms ◽  
Radiative Pressure

AbstractIs it shown that for those astronomical models of cosmic gamma-ray bursts (GRBs) which are associated with galactic neutron stars (NSs), the initial energy of the outburst could be converted to gamma-rays through processes of particle acceleration. The main emission mechanisms are considered for two basic alternatives, when particles are accelerated either by radiative pressure or by an electric field.Subject headings: acceleration of particles — gamma rays: bursts — radiation mechanisms: nonthermal

scholarly journals Symposium Summary and Concluding Remarks

2000 ◽  
Vol 195 ◽  
pp. 485-488
Author(s):  
G. B. Field
Keyword(s):  
Particle Acceleration ◽  
Gamma Ray ◽  
Panel Discussion ◽  
Gamma Ray Bursts

The symposium included invited papers, a panel discussion, and poster papers. In the following, I have summarized what to me were some of the more interesting parts of invited papers under the headings of trends, particle acceleration and heating, disks and jets, gamma-ray bursts, and other sources.

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