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Related papers: Gamma Ray Bursts in the comoving frame

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The jet opening angle theta_jet and the bulk Lorentz factor Gamma_0 are crucial parameters for the computation of the energetics of Gamma Ray Bursts (GRBs). From the ~30 GRBs with measured theta_jet or Gamma_0 it is known that: (i) the real…

High Energy Astrophysical Phenomena · Physics 2015-06-11 G. Ghirlanda , G. Ghisellini , R. Salvaterra , L. Nava , D. Burlon , G. Tagliaferri , S. Campana , P. D'Avanzo , A. Melandri

We estimate the initial bulk Lorentz factors Gamma_0 for GRBs that show the onset of the afterglow in their optical light curves. We find that Gamma_0 is strongly correlated with both the isotropic equivalent luminosity L_iso and energy…

High Energy Astrophysical Phenomena · Physics 2013-09-10 G. Ghirlanda , S. Campana , S. Covino , P. D'Avanzo , G. Ghisellini , A. Melandri , G. Tagliaferri , D. Burlon , L. Nava , R. Salvaterra

We recently found that Gamma Ray Burst energies and luminosities, in their comoving frame, are remarkably similar. This, coupled with the clustering of energetics once corrected for the collimation factor, suggests the possibility that all…

High Energy Astrophysical Phenomena · Physics 2012-11-12 G. Ghisellini , G. Ghirlanda , R. Salvaterra , L. Nava , D. Burlon , G. Tagliaferri , S. Campana , S. Covino , P. D'Avanzo , A. Melandri

Knowledge of the bulk Lorentz factor $\Gamma_{0}$ of GRBs allows us to compute their comoving frame properties shedding light on their physics. Upon collisions with the circumburst matter, the fireball of a GRB starts to decelerate,…

High Energy Astrophysical Phenomena · Physics 2018-01-31 G. Ghirlanda , F. Nappo , G. Ghisellini , A. Melandri , G. Marcarini , L. Nava , O. S. Salafia , S. Campana , R. Salvaterra

The bulk Lorentz factor of the gamma-ray burst (GRB) ejecta (Gamma_0) is a key parameter to understand the GRB physics. Liang et al. have discovered a correlation between Gamma_0 and isotropic gamma-ray energy:…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Jing Lv , Yuan-Chuan Zou , Wei-Hua Lei , Bing Zhang , Qing-Wen Wu , Ding-Xiong Wang , En-Wei Liang , Hou-Jun Lv

The initial Lorentz factor ($\Gamma_{\text{0}}$) plays a crucial role in uncovering the physical characteristics of gamma-ray bursts (GRBs). Previous studies have indicated that the ambient medium density index $k$ for GRBs falls in the…

High Energy Astrophysical Phenomena · Physics 2025-04-17 Sheng-Jin Sun , Shuang-Xi Yi , Yuan-Chuan Zou , Yu-Peng Yang , Ying Qin , Qing-Wen Tang , Fa-Yin Wang

We compile a sample of 93 long gamma-ray bursts (GRBs) from Fermi satellite and 131 from Konus-Wind, which have measured redshifts and well determined spectra, and estimate their pseudo Lorentz factors (${\Gamma_0}$) using the tight…

High Energy Astrophysical Phenomena · Physics 2019-05-15 Liang Xue , Fu-Wen Zhang , Si-Yuan Zhu

The characteristic photon energy for Gamma Ray Bursts, E_peak, has a remarkably narrow distribution for bursts of similar peak flux, with values between 150 and 600 keV for most faint bursts. This result is surprising within the framework…

Astrophysics · Physics 2009-11-07 Bradley E. Schaefer

We select a sample of 34 gamma-ray bursts (GRBs) whose $\Gamma_0$ values are derived with the onset peaks observed in the afterglow lightcurves (except for GRB 060218 whose $\Gamma_0$ is estimated with its radio data), and investigate the…

High Energy Astrophysical Phenomena · Physics 2015-11-11 En-Wei Liang , Ting-Ting Lin , Jing LV , Ruijing Lu , Jin Zhang , Bing Zhang

The correlations between the rest frame peak of the EF_E spectrum of GRBs Epeak and their isotropic energy (E_iso) or luminosity (L_iso) could have several implications for the understanding of the GRB prompt emission. These correlations…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Giancarlo Ghirlanda

We investigate the well-measured spectral and energetic properties of 20 gamma-ray bursts (GRBs) in their cosmological rest frames. We find a tight relation between the isotropic-equivalent gamma-ray energy Eiso, the local peak energy E'p…

Astrophysics · Physics 2007-05-23 D. Xu

Using a sample of 2408 time-resolved spectra for 91 BATSE gamma-ray bursts (GRBs) presented by Preece et al., we show that the relation between the isotropic-equivalent luminosity (L_iso) and the spectral peak energy (E_p) in the…

Astrophysics · Physics 2009-11-10 E. W. Liang , Z. G. Dai , X. F. Wu

Well-sampled optical lightcurves of 146 gamma-ray bursts (GRBs) are complied from the literature. Multiple optical emission components are extracted with power-law function fits to these lightcurves. We present a systematical analysis for…

High Energy Astrophysical Phenomena · Physics 2015-06-04 En-Wei Liang , Liang Li , Qing-Wen Tang , Jie-Min Chen , Bing Zhang

We derive the peak luminosity - peak energy (L_iso - E_peak) correlation using 22 long Gamma-Ray Bursts (GRBs) with firm redshift measurements. We find that its slope is similar to the correlation between the time integrated isotropic…

Astrophysics · Physics 2009-11-10 G. Ghirlanda , G. Ghisellini , C. Firmani , A. Celotti , Z. Bosnjak

We probe the existence of the E_peak-E_iso correlation in long GRBs using a sample of 442 BATSE bursts with known E_peak and with redshift estimated through the lag-luminosity correlation. This sample confirms that the rest frame peak…

Astrophysics · Physics 2009-11-10 G. Ghirlanda , G. Ghisellini , C. Firmani

Recently, Liang & Zhang (2005) found a tight correlation involving only observable quantities, namely the isotropic emitted energy $E_{\gamma,iso}$, the energy of the peak of the prompt spectrum $E^\prime_{p}$, and the jet break time…

Astrophysics · Physics 2009-11-11 L. Nava , G. Ghisellini , G. Ghirlanda , F. Tavecchio , C. Firmani

We report the discovery of a correlation among three prompt emission properties of GRBs. These are the isotropic peak luminosity L_iso, the peak energy of the time-integrated prompt emission spectrum E_pk, and the ``high signal" timescale…

Astrophysics · Physics 2009-11-11 C. Firmani , G. Ghisellini , V. Avila-Reese , G. Ghirlanda

The initial Lorentz factor ($\Gamma_{0}$) and jet half-opening angle ($\theta_{\rm jet}$) of gamma-ray bursts (GRBs) are critical physical parameters for understanding the dynamical evolution of relativistic jets and the true energy release…

High Energy Astrophysical Phenomena · Physics 2025-08-20 Jian Zhang , Bao-Cheng Qin , Lu-Lu Zhang , Fu-Wen Zhang

The peak time of optical afterglow may be used as a proxy to constrain the Lorentz factor Gamma of the gamma-ray burst (GRB) ejecta. We revisit this method by including bursts with optical observations that started when the afterglow flux…

High Energy Astrophysical Phenomena · Physics 2015-06-15 R. Hascoet , A. M. Beloborodov , F. Daigne , R. Mochkovitch

Long gamma-ray burst (GRB) prompt emission shows a correlation between the intrinsic peak energy, $E_{\mathrm{p,i}}$, of the time-average $\nu F_{\nu}$ spectrum and the isotropic-equivalent peak gamma-ray luminosity, $L_{{\rm p,iso}}$, as…

High Energy Astrophysical Phenomena · Physics 2025-10-17 Manuele Maistrello , Romain Maccary , Cristiano Guidorzi , Lorenzo Amati
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