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Cosmological X-Ray Flashes from Off-Axis Jets

Ryo Yamazaki·Kunihito Ioka·Takashi Nakamura
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Abstract

The of the cosmological X-ray flashes detected by WFC/BeppoSAX is calculated theoretically in a simple jet model. The total emission energy from the jet is assumed to be constant. We find that if the jet opening half-angle is smaller than 0.03 radian, off-axis emission from sources at z<~4 can be seen. The theoretical is less than 0.4, which is consistent with the observational result of 0.27+/-0.16 at the 1-sigma level. This suggests that the off-axis GRB jet with the small opening half-angle at the cosmological distance can be identified as the cosmological X-ray flash.

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Ryo Yamazaki, Kunihito Ioka, Takashi Nakamura. 2003-11-25. Cosmological X-Ray Flashes from Off-Axis Jets. https://doi.org/10.1063/1.1810813

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