Gamma-ray bursts in the comoving frame

By G. Ghirlanda, L. Nava, G. Ghisellini, A. Celotti, D. Burlon, S. Covino, A. Melandri. 2011

139 citations recorded by the source corpus.

We estimate the bulk Lorentz factor Γ0 of 31 gamma-ray bursts (GRBs) using the measured peak time of their afterglow light curves. We consider two possible scenarios for the estimate of Γ0: the case of a homogeneous circumburst medium or a wind density profile. The values of Γ0 are broadly distributed between few tens and several hundreds with average values ∼138 and ∼66 for the homogeneous and wind density profile, respectively. We find that the isotropic energy and luminosity correlate in a similar way with Γ0, i.e. and , while the peak energy Epeak∝Γ0. These correlations are less scattered in the wind density profile than in the homogeneous case. We then study the energetics, luminosities and spectral properties of our bursts in their comoving frame. The distribution of is very narrow with a dispersion of less than a decade in the wind case, clustering around  erg s−1. Peak photon energies cluster around ∼ 6 keV. The newly found correlations involving Γ0 offer a general interpretation scheme for the spectral energy correlation of GRBs. The Epeak–Eiso and Epeak–Liso correlations are due to the different Γ0 factors and the collimation-corrected correlation, Epeak–Eγ (obtained by correcting the isotropic quantities for the jet opening angle θj), can be explained if = constant. Assuming the Epeak–Eγ correlation as valid, we find a typical value of θjΓ0∼ 6–20, in agreement with the predictions of magnetically accelerated jet models.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/f8bd8ed25483ecdf67fddf61e15dda2fe3043c1a

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Bing Zhang
2. G. Ghirlanda
3. Z. Dai
4. Xuefeng Wu
5. Shan-Qin Wang
6. G. Ghisellini
7. L. Nava
8. I. -. Roma

In Nuclear and High Energy Physics

1. G. Ghirlanda
2. G. Ghisellini
3. Z. Cano
4. Shan-Qin Wang
5. Z. Dai
6. Xuefeng Wu
7. Bing Zhang
8. F. Tavecchio

Citations in the corpus

• A complete sample of bright Swift long gamma-ray bursts: testing the spectral-energy correlations (2011, background): “…the interpretation of these correlations (e.g. Eichler &Levinson 2004; Levinson & Eichler 2005; Rees & Mészáros 2005; Thompson, Mészáros & Rees 2007), an interesting progressha been recently made by studying the comoving properties of GRBs (Ghirlanda et al. 2012; Panaitescu et al. 2009).”
• The Observer's Guide to the Gamma-Ray Burst-Supernova Connection (2016, background): “the bulk Lorentz factor ΓB and the GRB luminosity [366, 367, 368].”