Broadband Light Curve Characteristics of Two Prototypical Low-Luminosity Gamma-Ray Bursts
It is recently suggested that low-luminosity gamma-ray bursts (LL-GRBs) are likely a unique GRB population.We present a systematical analysis of the light-curve characteristics from X-ray to gamma-ray bands for two prototypicalLL-GRBs, 980425 and 060218. It is found that both the pulse width (w) and the ratio of the rising width to the decaying width(r/d) of the two bursts are energy-dependent over a broad energy band. There exists a significant trend that the pulses tendto be narrower and more symmetrical at higher energy bands for the two events. Both the X-rays and gamma-rays follow thesame w-E and r/d -E relations. These facts may indicate that the X-ray emission tracks the gamma-ray emission, and bothare likely to originate from the same physical mechanism. Their light curves show significant spectral lags. We calculate thethree types of lags with the pulse peaking time (tpeak), the pulse centroid time (tcen), and the cross-correlation function (CCF).The lag calculated by CCF is strongly correlated with that derived from tpeak, but the lag derived from tcen is less correlatedwith that derived from tpeak and CCF. We also find that their pulse temporal characteristics are normal when compared to theother normal BATSE GRB pulses, indicating that GRBs 980425 and 060218 may share a similar radiation physics with them.
gamma-rays bursts
Fu-Wen Zhang
National Astronomical Observatories/Yunnan Observatory,Chinese Academy of Sciences,P.O.Box 110,Kunming,Yunnan 650011,China Department of Mathematics and Physics,Guilin niversity of Technology,Guilin,Guangxi 541004,China The Graduate School of the Chinese
国际会议
2008 NanJing Gamma-Ray Burst Conference(2008年伽马暴国际研讨会)
南京
英文
47-50
2008-06-23（万方平台首次上网日期，不代表论文的发表时间）