arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2101.08296astro-ph.HE
收藏

伽玛暴X射线谱中黑体成分的综合研究

A comprehensive view of blackbody components in the X-ray spectra of GRBs

Vlasta Valan, Josefin Larsson

摘要:

在X射线谱中,有一小部分伽马射线暴(GRB)表现出黑体辐射,其起源一直存在争议。为了更全面地理解这一现象,我们用{ \it Swift}~XRT对116个已知红移的伽玛暴进行了黑体成分的搜索。进行时间分辨光谱分析和黑体的重要性进行评估相对于一个吸收的幂律模型。我们报告了9个新的探测结果,证实了以前报道的GRB~ 171205 A中的黑体。加上我们以前的结果,在{ \it Swift} 13年来观测到的199个伽玛暴样本中,总共有19个伽玛暴具有显著的黑体发射。探测到一个短伽玛暴和两个低光度伽玛暴。我们根据黑体分量估计火球参数,并注意到黑体亮度与温度和推断的洛伦兹因子相关。黑体成分和光变曲线的性质有很大的差异,这表明发射的来源不同。在大约三分之一的伽玛暴中,黑体显然与喷流的晚期瞬发辐射有关。样本的其余部分包括与茧的预期完全一致的情况,以及可能由高纬度排放或更有活力的茧解释的情况。这些结果表明,热辐射与射流的所有部分。

英文摘要:

A small fraction of gamma-ray bursts (GRBs) exhibit blackbody emission in the X-ray spectra, the origin of which is debated. In order to gain a more complete understanding of this phenomenon, we present a search for blackbody components in 116 GRBs with known redshifts observed by {\it Swift}~XRT. A time-resolved spectral analysis is carried out and the significance of the blackbody is assessed with respect to an absorbed power-law model. We report nine new detections and confirm the previously reported blackbody in GRB~171205A. Together with our previous results, there are a total of 19 GRBs with significant blackbody emission in a sample of 199 GRBs observed by {\it Swift} over 13 years. The detections include one short GRB and two low-luminosity GRBs. We estimate fireball parameters from the blackbody components and note that the blackbody luminosity is correlated with the temperature and inferred Lorentz factor. There is a large spread in the properties of the blackbody components and the light curves, which points to different origins for the emission. In about a third of the GRBs, the blackbody is clearly associated with late prompt emission from the jet. The rest of the sample includes cases that are fully consistent with the expectations from a cocoon, as well cases that may be explained by high-latitude emission or more energetic cocoons. These results indicate that thermal emission is associated with all parts of the jet.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑