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Related papers: The peak energy of dissipative GRB photospheres

200 papers

It is proposed that the prompt emission observed in bursts that exhibit a thermal component originates from relativistic radiation mediated shocks that form below the photosphere of the GRB outflow. It is argue that such shocks are expected…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Omer Bromberg , Ziv Mikolitzky , Amir Levinson

Using a simple off-axis jet model of GRBs, we can reproduce the observed unusual properties of the prompt emission of GRB980425, such as the extremely low isotropic equivalent gamma-ray energy, the low peak energy, the high fluence ratio,…

Astrophysics · Physics 2009-11-16 Ryo Yamazaki , Daisuke Yonetoku , Takashi Nakamura

The properties of gamma-ray bursts (GRBs) that are inferred from observations depend on the value of the bulk Lorentz factor, $\Gamma$. Consequently, accurately estimating it is an important aim. In this work, we present a method of…

High Energy Astrophysical Phenomena · Physics 2025-06-12 Oscar Wistemar , Felix Ryde , Filip Alamaa

The optical and gamma-ray observations of GRB 080319B allow us to determine a fairly complete physical picture for this remarkable burst. The data indicate that the prompt optical and gamma-ray photons were produced at the same location but…

Astrophysics · Physics 2010-05-12 P. Kumar , A. Panaitescu

Recent observations, especially by the Fermi satellite, point out the importance of the thermal component in GRB spectra. This fact revives strong interest in photospheric emission from relativistic outflows. Early studies already suggested…

High Energy Astrophysical Phenomena · Physics 2013-12-03 Gregory Vereshchagin

GRB110721A was observed by the Fermi Gamma-ray Space Telescope using its two instruments the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). The burst consisted of one major emission episode which lasted for ~24.5 seconds…

High Energy Astrophysical Phenomena · Physics 2012-09-19 The Fermi LAT Collaboration , the GBM Collaboration , A. Pe'er

Using data mostly assembled by previous authors, we consider the linear correlation between the apparent radiative efficiency $\epsilon_{\gamma}$ (defined as the ratio of isotropic equivalent radiative output to inferred isotropic…

Astrophysics · Physics 2009-11-10 David Eichler Daniel Jontof-Hutter

Gamma-ray bursts (GRBs) are the most powerful explosions in the universe. How efficiently the jet converts its energy to radiation is a long-standing problem and it is poorly constrained. The standard model invokes a relativistic fireball…

We discuss the prompt emission of Gamma-Ray Bursts in different spectral energy bands. First, we suggest that a three-part synchrotron emission model is a good description of the ~20 keV - 1 MeV gamma-ray emission of GRBs. We show that this…

Astrophysics · Physics 2009-11-07 Nicole M. Lloyd-Ronning

We explore the properties of photospheric emission in the context of long gamma-ray bursts (LGRBs) using three numerical models that combine relativistic hydrodynamical simulations and Monte Carlo radiation transfer calculations in three…

High Energy Astrophysical Phenomena · Physics 2023-07-20 Hirotaka Ito , Jin Matsumoto , Shigehiro Nagataki , Donald C. Warren , Maxim V. Barkov , Daisuke Yonetoku

The emission process responsible for the so-called "prompt" emission of gamma-ray bursts is still unknown. A number of empirical models fitting the typical spectrum still lack a satisfactory interpretation. A few GRB spectral catalogues…

High Energy Astrophysical Phenomena · Physics 2011-05-03 C. Guidorzi , M. Lacapra , F. Frontera , E. Montanari , L. Amati , F. Calura , L. Nicastro , M. Orlandini

Emission from the photosphere in gamma-ray burst (GRB) jets can be substantially affected by subphotospheric energy dissipation, which is typically caused by radiation-mediated shocks (RMSs). We study the observational characteristics of…

High Energy Astrophysical Phenomena · Physics 2023-10-25 Filip Samuelsson , Felix Ryde

Recently proposed correlations between the energetics of Gamma-Ray Bursts (GRB) and their spectral properties, namely the peak energy of their prompt emission, are found to account for the observed fluence distribution of all `bright' BATSE…

Astrophysics · Physics 2007-05-23 Z. Bosnjak , A. Celotti , F. Longo , G. Barbiellini

We examine 288 GRBs detected by the Fermi Gamma-ray Space Telescope's Gamma-ray Burst Monitor (GBM) that fell within the field-of-view of Fermi's Large Area Telescope (LAT) during the first 2.5 years of observations, which showed no…

High Energy Astrophysical Phenomena · Physics 2015-06-03 LAT Collaboration , GBM Collaboration

Gamma-ray bursts (GRBs) are the most brilliant objects in the Universe but efforts to estimate the total energy released in the explosion -- a crucial physical quantity -- have been stymied by their unknown geometry: spheres or cones. We…

The high energy emission from Gamma-ray Bursts has some interesting features, including the absence of the GeV excess in the prompt spectrum, the delayed onset of the GeV emission, and the longer duration of the GeV emission than the prompt…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-16 Yi-Zhong Fan

In this work we numerically calculate the thermal radiation efficiency of the baryonic outflow. The possible outflow acceleration in the transparent stage, which lowers thermal radiation efficiency, has been taken into account. In the…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-07 Yi-Zhong Fan

Ultra-relativistic motion and efficient conversion of kinetic energy to radiation are required by gamma-ray burst (GRB) observations, yet they are difficult to simultaneously achieve. Three leading mechanisms have been proposed to explain…

High Energy Astrophysical Phenomena · Physics 2016-04-06 Damien Bégué , J. Michael Burgess

Some recent experiments detecting very high energy (VHE) gamma-rays above 10-20 TeV independently reported VHE bursts for some of bright gamma-ray bursts (GRBs). If these signals are truly from GRBs, these GRBs must emit a much larger…

Astrophysics · Physics 2009-10-31 Tomonori Totani

High-energy photons emitted from gamma-ray bursts (GRBs) are subject to pair-production interactions with lower energy photons, leading to an effective optical depth. In this Letter, we estimate the opacity resulting from photon fields…

High Energy Astrophysical Phenomena · Physics 2010-11-02 Rudy C. Gilmore , Enrico Ramirez-Ruiz