A new luminosity relation for gamma-ray bursts and its implication

Abstract

Gamma-ray bursts (GRBs) are the most luminous astrophysical events observed so far. They are conventionally classified into long and short ones depending on their time duration, $T_{90}$. Because of the advantage their high redshifts offer, many efforts have been made to apply GRBs to cosmology. The key to this is to find correlations between some measurable properties of GRBs and the energy or the luminosity of GRBs. These correlations are usually referred to as luminosity relations and are helpful in understanding the GRBs themselves. In this paper, we explored such correlations in the X-ray emission of GRBs. The X-ray emission of GRBs observed by \emph{Swift} has the exponential functional form in the prompt phase and relaxes to a power-law decay at time $T_p$. We have assumed a linear relation between $\log L_{X,p}$ (with $L_{X,p}$ being the X-ray luminosity at $T_p$) and $\log [T_p/(1+z)]$, but there is some evidence for curvature in the data and the true relationship between $L_{X,p}$ and $T_p/(1+z)$ may be a broken power law. The limited GRB sample used in our analysis is still not sufficient for us to conclude whether the break is real or just an illusion caused by outliers. We considered both cases in our analysis and discussed the implications of the luminosity relation, especially on the time duration of GRBs and their classification.

7 pages, 5 figures, 1 table; language edit, published in The Astrophysical Journal

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Cited by in corpus (14)

• Gamma-ray Burst Cosmology
• Measuring dark energy with the $E_{\mathrm{iso}}-E_{\mathrm{p}}$ correlation of gamma-ray bursts using model-independent methods
• Luminosity--time and luminosity--luminosity correlations for GRB prompt and afterglow plateau emissions
• The updated luminosity correlations of gamma-ray bursts and cosmological implications
• Gamma-ray burst prompt correlations: selection and instrumental effects
• Constraining cosmological parameters by Gamma Ray Burst X - ray afterglow lightcurves
• Non-parametric study of the evolution of the cosmological equation of state with SNeIa, BAO and high redshift GRBs
• Gamma Ray Burst Prompt correlations
• A new three-parameter correlation for gamma-ray bursts with a plateau phase in the afterglow
• Luminosity correlations for gamma-ray bursts and implications for their prompt and afterglow emission mechanisms
• Toward tight gamma-ray burst luminosity relations
• GRBs and fundamental physics
• Systematics in the Gamma Ray Bursts Hubble diagram
• $f(T,B)$ cosmography for high redshifts