scholarly journals Gamma-ray bursts: not so much deadlier than we thought

2020 ◽  
Vol 500 (2) ◽  
pp. 1970-1973
Author(s):  
Brian C Thomas ◽  
Dimitra Atri ◽  
Adrian L Melott
Keyword(s):  
Gamma Ray ◽  
Planetary Atmospheres ◽  
Muon Flux ◽  
Gamma Ray Bursts ◽  
Gamma Ray Burst ◽  
Planet Surface ◽  
Prompt Emission

ABSTRACT We analyse the additional effect on planetary atmospheres of recently detected gamma-ray burst afterglow photons in the range up to 1 TeV. For an Earth-like atmosphere, we find that there is a small additional depletion in ozone versus that modeled for only prompt emission. We also find a small enhancement of muon flux at the planet surface. Overall, we conclude that the additional afterglow emission, even with TeV photons, does not result in a significantly larger impact over that found in past studies.

scholarly journals GAMMA-RAY BURSTS: PROGRESS, PROBLEMS & PROSPECTS

2004 ◽  
Vol 19 (15) ◽  
pp. 2385-2472 ◽  
Author(s):  
BING ZHANG ◽  
PETER MÉSZÁROS
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Current Understanding ◽  
Shock Model ◽  
Gamma Ray Burst ◽  
Prompt Emission

The cosmological gamma-ray burst (GRB) phenomenon is reviewed. The broad observational facts and empirical phenomenological relations of the GRB prompt emission and afterglow are outlined. A well-tested, successful fireball shock model is introduced in a pedagogical manner. Several important uncertainties in the current understanding of the phenomenon are reviewed, and prospects of how future experiments and extensive observational and theoretical efforts may address these problems are discussed.

scholarly journals Gamma-Ray Burst Prompt Correlations

2018 ◽  
Vol 2018 ◽  
pp. 1-31 ◽  
Author(s):  
M. G. Dainotti ◽  
R. Del Vecchio ◽  
M. Tarnopolski
Keyword(s):  
Gamma Ray ◽  
Theoretical Models ◽  
Gamma Ray Bursts ◽  
Gamma Ray Burst ◽  
The Past ◽  
Two Parameter ◽  
Prompt Emission

The mechanism responsible for the prompt emission of gamma-ray bursts (GRBs) is still a debated issue. The prompt phase-related GRB correlations can allow discriminating among the most plausible theoretical models explaining this emission. We present an overview of the observational two-parameter correlations, their physical interpretations, and their use as redshift estimators and possibly as cosmological tools. The nowadays challenge is to make GRBs, the farthest stellar-scaled objects observed (up to redshift z=9.4), standard candles through well established and robust correlations. However, GRBs spanning several orders of magnitude in their energetics are far from being standard candles. We describe the advances in the prompt correlation research in the past decades, with particular focus paid to the discoveries in the last 20 years.

scholarly journals RAPID OPTICAL FOLLOW-UP OBSERVATIONS OF GAMMA-RAY BURSTS

2012 ◽  
Vol 12 ◽  
pp. 48-57
Author(s):  
MICHEL BOËR
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Optical Observations ◽  
Gamma Ray Burst ◽  
Infrared Wavelengths ◽  
New Instruments ◽  
Prompt Emission

The prompt emission of gamma-ray burst sources is still the main means of detection, and a privilegied access to the souce dynamics. It is detected from radio to GeV energies, and its study is crucial for the overall understanding of the phenomenom. We present here a panorama of the rapid optical observations, and what can be infered from the data. We will discuss also the new instruments which are planned for the observation of the prompt and early afterglow at optical and infrared wavelengths, with spectral capabilities.

STOCHASTIC WAKEFIELD PLASMA ACCELERATION IN GAMMA-RAY BURSTS

2007 ◽  
Vol 21 (03n04) ◽  
pp. 627-632
Author(s):  
G. BARBIELLINI ◽  
F. LONGO ◽  
N. OMODEI ◽  
D. GIULIETTI ◽  
A. CELOTTI ◽  
...  
Keyword(s):  
Particle Acceleration ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Low Energy ◽  
Plasma Acceleration ◽  
Gamma Ray Burst ◽  
Initial Burst ◽  
X Ray ◽  
Wake Field ◽  
Prompt Emission

Gamma-Ray Burst (GRB) prompt emission can, for specific conditions, be so powerful and short-pulsed to strongly influence any surrounding plasma. In this paper, we briefly discuss the possibility that a very intense initial burst of radiation produced by GRBs satisfy the intensity and temporal conditions to cause stochastic wake-field particle acceleration in a surrounding plasma of moderate density. We consider a simple but realistic GRB model for which particle wake-field acceleration can first be excited by a very strong low-energy precursor, and then be effective in producing the observed prompt X-ray and gamma-ray GRB emission.

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.

scholarly journals Optical Afterglows as Probes for the Central Engine and Fireball of Gamma-Ray Bursts

2012 ◽  
Vol 8 (S290) ◽  
pp. 263-264
Author(s):  
Liang Li ◽  
En-Wei Liang ◽  
He Gao ◽  
Bing Zhang
Keyword(s):  
Statistical Analysis ◽  
Gamma Rays ◽  
Density Profile ◽  
Gamma Ray ◽  
Ambient Medium ◽  
Gamma Ray Bursts ◽  
Prompt Gamma ◽  
Medium Density ◽  
Central Engine ◽  
Prompt Emission

AbstractWell-sampled optical lightcurves of 146 gamma-ray bursts (GRBs) are compiled from literature. We identify possible emission components based on our empirical fits and present statistical analysis for these components. We find that the flares are related to prompt emission, suggesting that they could have the same origin in different episodes. The shallow decay segment is not correlated with prompt gamma-rays. It likely signals a long-lasting injected wind from GRB central engines. Early after onset peak is closely related with prompt emission. The ambient medium density profile is likely n ∝ r−1. No correlation between the late re-brightening bump and prompt gamma-rays or the onset bump is found. They may be from another jet component.

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 Evidence of X-Ray Plateaus Driven by the Magnetar Spindown Winds in Gamma-Ray Burst Afterglows

2021 ◽  
Vol 922 (2) ◽  
pp. 102
Author(s):  
Shu-Jin Hou ◽  
Shuang Du ◽  
Tong Liu ◽  
Hui-Jun Mu ◽  
Ren-Xin Xu
Keyword(s):  
Gamma Ray ◽  
Normal Component ◽  
Gamma Ray Bursts ◽  
Cutting Edge ◽  
Decay Phase ◽  
Gamma Ray Burst ◽  
X Ray ◽  
Central Engine

Abstract The central engine of gamma-ray bursts (GRBs) remains an open and cutting-edge topic in the era of multimessenger astrophysics. X-ray plateaus appear in some GRB afterglows, which are widely considered to originate from the spindown of magnetars. According to the stable magnetar scenario of GRBs, an X-ray plateau and a decay phase ∼t −2 should appear in X-ray afterglows. Meanwhile, the “normal” X-ray afterglow is produced by the external shock from a GRB fireball. We analyze the Neil Gehrels Swift GRB data, then find three gold samples that have an X-ray plateau and a decay phase ∼t −2 superimposed on the jet-driven normal component. Based on these features of the lightcurves, we argue that the magnetars should be the central engines of these three GRBs. Future joint multimessenger observations might further test this possibility, which can then be beneficial to constrain GRB physics.

scholarly journals Prompt emission from the counter jet of a short gamma-ray burst

2018 ◽  
Vol 2018 (3) ◽  
Author(s):  
Ryo Yamazaki ◽  
Kunihito Ioka ◽  
Takashi Nakamura
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Burst ◽  
Prompt Emission

scholarly journals The properties of prompt emission in short gamma-ray bursts with extended emission observed by Fermi/GBM

2020 ◽  
Vol 492 (3) ◽  
pp. 3622-3630
Author(s):  
Lin Lan ◽  
Rui-Jingi Lu ◽  
Hou-Jun Lü ◽  
Jun Shen ◽  
Jared Rice ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Large Scatter ◽  
Intrinsic Properties ◽  
Temporal Properties ◽  
Peak Energy ◽  
Peak Flux ◽  
Short Grbs ◽  
Prompt Emission ◽  
Extended Emission

ABSTRACT Short gamma-ray bursts (GRB) with extended emission (EE) that are composed of an initial short hard spike followed by a long-lasting EE are thought to comprise a sucategory of short GRBs. The narrow energy band available during the Swift era, combined with a lack of spectral information, prevented the discovery of the intrinsic properties of these events. In this paper, we perform a systematic search of short GRBs with EE using all available Fermi/GBM data. The search identified 26 GBM-detected short GRBs with EE that are similar to GRB 060614 observed by Swift/BAT. We focus on investigating the spectral and temporal properties of both the hard spike and the EE component of all 26 GRBs, and explore differences and possible correlations between them. We find that while the peak energy (Ep) of the hard spikes is slightly harder than that of the EE, their fluences are comparable. The harder Ep seems to correspond to a larger fluence and peak flux, with a large scatter for both the hard spike and the EE component. Moreover, the Ep of both the hard spike and the EE are compared with other short GRBs. Finally, we also compare the properties of GRB 170817A with those of short GRBs with EE and find no significant statistical differences between them. We find that GRB 170817A has the lowest Ep, probably because it is off-axis.

Sign in / Sign up

Export Citation Format

Share Document