Pihlström 2007 GRB030329的晚期几年的射电余辉观测
主要内容:
用VLBI给出了GRB030329直到806天以后的射电观测。测得了流量,速度和尺度等。
精彩摘抄:射电光变1000天。
文章信息:
Stirring the Embers: High Sensitivity VLBI Observations of GRB030329
(Submitted on 17 Apr 2007)
Abstract: We present high sensitivity Very Long Baseline Interferometry (VLBI) observations 806 days after the gamma-ray burst of 2003 March 29 (GRB030329). The angular diameter of the radio afterglow is measured to be 0.347 +- 0.09 mas, corresponding to 0.99 +- 0.26 pc at the redshift of GRB030329 (z = 0.1685). The evolution of the image size favors a uniform external density over an R^-2 wind-like density profile (at distances of R >~10^18 cm from the source), although the latter cannot be ruled out yet. The current apparent expansion velocity of the image size is only mildly relativistic, suggesting a non-relativistic transition time of t_NR ~ 1 yr. A rebrightening, or at least a significant flattening in the flux decay, is expected within the next several years as the counter-jet becomes visible (this has not yet been observed). An upper limit of <1.9c> Comments:
16 pages, 5 figures, accepted for publication in Astrophysical Journal
Subjects:
Astrophysics (astro-ph)
Cite as:
arXiv:0704.2085v1 [astro-ph]
没有评论:
发表评论