Are Gamma-ray Bursts Universal?

Abstract

It is noted that the Liang-Zhang correlation can be accounted for with the viewing angle interpretation proposed earlier. The Ghirlanda correlation, recently generalized by Nava et al (2006) to a wind profile, can be accounted for by the viewing angle interpretation accordingly generalized to a wind profile. Most of the scatter in the spectra and time-integrated brightness in $\gamma$-ray bursts (GRB) can thus be accounted for by variation in two parameters, 1) the viewing angle and 2) the jet opening angle, with very little variation in any other intrinsic parameters. The scatter in apparent isotropic equivalent fluence and other parameters is reduced by a factor of order 30 when each of these parameters is considered. Possible difficulties with alternative explanations are briefly discussed. It is also noted that the relative scatter in the Amati and Ghirlanda correlations suggests certain conclusions about the inner engine.

References in corpus (9)

• Evidence for a Canonical GRB Afterglow Light Curve in the Swift/XRT Data
• Dissipative Photosphere Models of Gamma-ray Bursts and X-ray Flashes
• Model-Independent Multi-Variable Gamma-Ray Burst Luminosity Indicator and Its Possible Cosmological Implications
• Probing the environment in Gamma-ray bursts: the case of an X-ray precursor, afterglow late onset and wind vs constant density profile in GRB011121 and GRB011211
• The Case for Anisotropic Afterglow Efficiency within Gamma-Ray Burst Jets
• On the interpretation of the spectral--energy correlations in long Gamma--Ray Bursts
• The Difference Between the Amati and Ghirlanda Relations
• The Blast Energy Efficiency of GRBs
• Delayed Afterglow Onset Interpreted as Baryon-Poor Viewing Angle

Cited by in corpus (10)

• Gamma-Ray Bursts in the Swift Era
• Gamma-ray Burst Cosmology
• High-Energy Aspects of Astrophysical Jets
• A Uniform Correlation between Synchrotron Luminosity and Doppler Factor in Gamma-ray Bursts and Blazars: hint of similar intrinsic luminosities?
• A backscattering dominated prompt emission model for the prompt phase of Gamma ray bursts
• Spectral Lags Explained as Scattering from Accelerated Scatterers
• Cloaked Gamma Ray Bursts
• A Model for Fast Rising, Slowly Decaying Subpulses in Gamma-Ray Bursts
• Short GRBs Viewed from Far Off Axis
• Luminosity Selection for Gamma Ray Burst