2005/08/03 by Daniel E. Reichart, Reichart, Daniel E., Melissa C. Nysewander +1
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0508111
Submitted to The Astrophysical Journal (Letters), 7 pages, 2 Figures, LaTeX
arxiv created 2005/08/03 · arxiv updated 2009/12/01
Recently, Guidorzi et al. (2005) expanded the size of the sample of GRBs for which variabilities and peak luminosities have been measured, from 11 to 32. They confirm the existence of a correlation, but find a dramatically different relationship between L and V than had originally been found. We find that this is the result of improper statistical methodology. When we fit a model to the data that accommodates both statistical variance (in two dimensions) and sample variance, we find that L ~ V3.4(+0.9,-0.6) with a sample variance of sigmalogV = 0.20(+0.04,-0.04), which is consistent with the original finding of Reichart et al. (2001) -- L ~ V3.3(+1.1,-0.9) with a sample variance of sigmalogV = 0.18(+0.07,-0.05) -- and inconsistent with the finding of Guidorzi et al. (2005): L ~ V1.3(+0.8,-0.4) with sample variance assumed to be zero.