GRB 990123光学后照的衰变:对火球模型的影响
A J Castro-Tirado1, M R Zapatero-Osorio, N Caon
1Instituto de Astrofisica de Andalucia, IAA-CSIC, Granada, Spain. Instituto de Astrofisica de Canarias, La Laguna, Tenerife, Spain. Astronomical Observatory, University of Copenhagen, Copenhagen, Denmark. Nordic Optical Telescope, La Palma, T.
概括
对玛射线爆发GRB 990123的观测揭示了一个平稳下降的光曲线. 有证据表明,合并喷气可能是事件后观察到的更的下降速度的原因.
科学领域:
- * 天体物理学 * 天体物理学
- *高能天体物理学 *高能天体物理学
- * 观测宇宙学是一种观测性宇宙学.
背景情况:
- * 马射线爆发 (GRBs) 是宇宙中最明亮的电磁事件.
- * 了解GRB发射机制和原始系统对于天体物理学至关重要.
- *GRB 990123是一个非常明亮的事件,为详细研究提供了独特的机会.
研究的目的:
- * 为了分析GRB 990123.3的宽带后照.
- * 为了研究GRB 990123后照的时间和光谱演变.
- *为了限制排放模型和探测GRB喷射的性质.
主要方法:
- *从紫外线到近红外线进行了宽带观测,从事件发生后8.5小时开始.
- *利用了来自机器人望远镜和短暂源实验 (ROTSE) 和哈勃太空望远镜 (HST) 的数据.
- *分析了光线曲线的时间衰变速率和颜色演变.
主要成果:
- * 在GRB 990123.3的后照中观察到一个平稳下降的光曲线.
- * 确定了颜色依赖,可能与事件发生后1天左右紫外线光学波段的冷却中断有关.
- *在1.5到2天后检测到更的下降率,表明喷气式聚合.
结论:
- *GRB 990123的后发光光曲线与平稳膨胀的火球的辐射一致.
- *观察到的冷却中断表明了排放机制或粒子冷却的过渡.
- * 较的衰变指向一个相对论的,对齐的喷气结构,朝着观察者方向.
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