The updated Bulk Lorentz Factors of Gamma-Ray Burst X-Ray Flares

• 来源期刊: 天文和天体物理学研究
• 年，卷（期）: 2017,（6）
• 页码范围: 37-46
• 页数: 10页
• 语种: 英文
• DOI: 10.1088/1674-4527/17/6/53

摘要

X-ray flares are the most common phenomena in the afterglow phase of gamma-ray bursts (GRBs) in the Swift era,and are known as a canonical component in X-ray afterglows.In this work,we constrain the Lorentz factor of X-ray flares with an updated sample.We extensively search for X-ray light curves showing flare and jet break simultaneously.A smooth broken power law function is used to fit the jet breaks in 11 GRBs.We also use a smooth broken power law function to fit the profile of X-ray flares,and the total number of the flares is 20.We obtain the lower and upper limits of Lorentz factor (Fx) with the timescale,half-opening angle and mean luminosity of the X-ray flares for interstellar medium (ISM) and wind cases.The lower limits on Γx range from tens to a few hundred,and the upper limits are mainly about a few hundred.We also apply the limited Lorentz factor to test correlations of Γo-Eγ,iso and Γ0-Lγ,iso for GRBs,and find X-ray flares in the ISM case are much more consistent with those of prompt emission than the wind case in a statistical sense for both correlations.X-ray flares are almost consistent with the trend in the correlations of Γ0-Eγ,iso(Lγ,iso) for prompt GRBs,indicating X-ray flares and prompt bursts may have the same physical origin.