Characteristic Variability Time Scales of Long Gamma-Ray Bursts

Abstract

We determined the characteristic variability time scales (Δt_p) of 410 bright and long GRBs, by locating the peaks of their Power Density Spectra, defined and calculated in the time domain. We found that the averaged variability time scale decreases with the peak flux. This is consistent with the time-dilation effect expected for the cosmological origin of GRBs. We also found that the occurrence distribution of the characteristic variability time scale shows bimodality, which might be interpreted as that the long GRB sample is composed of two sub-classes with different variability time scales. However, we found no difference for some other characteristics of these two sub-classes.

10 pages, 5 figures, corrected some typos and syntaxes, enlarged the label fonts in fig.3 and fig.5

References in corpus (5)

• Time Scales in Long GRBs
• Reclassification of gamma-ray bursts
• Temporal properties of the short gamma-ray bursts
• Timing in the Time Domain: Cygnus X-1
• Power Spectra of X-ray Binaries

Cited by in corpus (8)

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• Dead Zone Formation and Nonsteady Hyperaccretion in Collapsar Disks : A Possible Origin of Short-Term Variability in the Prompt Emission of Gamma-Ray Bursts
• Correlation between peak energy and Fourier power density spectrum slope in gamma-ray bursts
• UV/Optical Emission Accompanying Gamma-ray Burst
• A Comprehensive Analysis of Insight-HXMT Gamma-Ray Burst Data. I. Power Density Spectrum
• The Variability of Gamma-Ray Bursts that Create Afterglows