GRB 990712: First indication of polarization variability in a gamma-ray burst afterglow

被引：51

作者：

Rol, E

Wijers, RAMJ

Vreeswijk, PM

Kaper, L

Galama, TJ

van Paradijs, J

Kouveliotou, C

Masetti, N

Pian, E

Palazzi, E

Frontera, F

van den Heuvel, EPJ

机构：

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

[2] SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA

[3] CALTECH, Pasadena, CA 91125 USA

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

[5] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA

[6] Univ Ferrara, Dept Phys, I-44100 Ferrara, Italy

来源：

ASTROPHYSICAL JOURNAL | 2000年 / 544卷 / 02期

关键词：

gamma rays : bursts; polarization; radiation mechanisms : nonthermal turbulence;

D O I：

10.1086/317256

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We report the detection of significant polarization in the optical afterglow of GRB 990712 on three instances: 0.44, 0.70, and 1.45 days after the gamma-ray burst, with (P, theta) being (2.9% +/- 0.4%, 121 degrees .1 +/- 3 degrees .5), (1.2% +/- 0.4%, 116 degrees .2 +/- 10 degrees .1), and (2.2% +/- 0.7%, 139 degrees .2 +/- 10 degrees .4), respectively. The polarization is intrinsic to the afterglow. The degree of polarization is not constant and is smallest at the second measurement. The polarization angle does not vary significantly during these observations. We find that none of the existing models predict such polarization Variations at a constant polarization angle; we suggest ways in which these models might be modified to accommodate the observed behavior of this afterglow.

引用

页码：707 / 711

页数：5

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