Radio-to-X-ray spectrum of GRB 970508 on 1997 May 21.0 UT

被引：103

作者：

Galama, TJ

Wijers, RAMJ

Bremer, M

Groot, PJ

Strom, RG

Kouveliotou, C

van Paradijs, J

机构：

[1] Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands

[2] Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands

[3] Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England

[4] Inst Radio Astron Millimetr, F-38406 St Martin Dheres, France

[5] Netherlands Fdn Radio Astron, NL-7990 AA Dwingeloo, Netherlands

[6] Univ Space Res Assoc, Washington, DC USA

[7] Univ Alabama, Dept Phys, Huntsville, AL 35899 USA

来源：

ASTROPHYSICAL JOURNAL | 1998年 / 500卷 / 02期

基金：

美国国家航空航天局;

关键词：

gamma rays : bursts; gamma rays : observations;

D O I：

10.1086/311425

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We have reconstructed the spectrum of the afterglow of GRB 970508 on 1997 May 21.0 UT (12.1 days after the gamma-ray burst) on the basis of observations spanning the X-ray-to-radio range. The low-frequency power-law index of the spectrum, alpha = 0.44 +/- 0.07 (F-nu proportional to nu(alpha)), is in agreement with the expected value alpha = 1/3 for optically thin synchrotron radiation. The 1.4 GHz emission is self-absorbed. We infer constraints on the break frequencies nu(c) and nu(m) on 1997 May 21.0 UT from a spectral transition from F-nu similar to nu(-0 6) to F-nu similar to nu(-1.1) in the optical passband around 1.4 days. A model of an adiabatically expanding blast wave emitting synchrotron radiation, in which a significant fraction of the electrons cool rapidly, provides a successful and consistent description of the afterglow observations over nine decades in frequency, ranging in time from trigger until several months later.

引用

页码：L97 / L100

页数：4