Gravitational microlensing of gamma-ray burst afterglows by single and binary stars

被引:26
作者
Mao, S [1 ]
Loeb, A
机构
[1] Univ Manchester, Jodrell Bank Observ, Macclesfield SK11 9DL, Cheshire, England
[2] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
基金
美国国家科学基金会;
关键词
binaries : general; cosmology : theory; gamma rays : bursts; gravitational lensing;
D O I
10.1086/318912
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We calculate the magnification light curves caused by stellar microlensing of gamma-ray burst (GRB) afterglows. A GRB source appears on the sky as a thin ring that expands faster than the speed of light and is maximally magnified as it crosses the lens caustics. While a single-star lens produces a single peak in the magnification light curve, binary-star lenses may produce multiple peaks. The shape of the magnification light curve provides invaluable information on the surface brightness distribution of the afterglow photosphere on submicroarcsecond scales. We find that all afterglows are likely to show variability at the level of a few percent about a year following the explosion, caused by stars that are separated by tens of Einstein radii from their line of sight.
引用
收藏
页码:L97 / L101
页数:5
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