Interpretation of radio afterglows in the framework of the standard fireball and energy injection models
Interpretation of radio afterglows in the framework of the standard fireball and energy injection models
复制标题
标准火球和能量注入模型框架下射电余辉的解释
DOI：
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发表时间：
2022
影响因子：
4.8
通讯作者：
N. Lloyd
中科院分区：
文献类型：
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作者：
D. Levine;M. Dainotti;N. Fraija;D. Warren;P. Chandra;N. Lloyd
伽马射线暴(GRB)是一种全色、高能瞬变，其能量发射机制仍有争议。一种可能的解释是标准火球模型，它可以用伽玛暴的闭合关系(CRS)或时间指数和光谱指数之间的关系进行检验。为了测试这些，我们汇编了一个从1997年到2020年的射电余辉曲线(LCS)的广泛样本，这是迄今为止用射电观测对伽玛暴进行的最全面的分析。我们从82个不同的伽玛暴中拟合了202个LCS，得到了26个显示明显断裂的样本和14个呈现射电平台区的伽玛暴的子样本。我们测试了这些样本对应于恒定密度星际介质或恒星风介质在快冷和慢冷状态下的CRS，以及在n∝r−k之后的三个额外的密度分布，k=1，1.5，2.5.并考虑了有能量注入和没有能量注入的CRS集合。我们发现，26个伽玛暴中有12个(46%)，其中7/12呈现射电高原，在测试的集合中至少有一个CR，这表明我们的数据在很大程度上与标准的火球模型不兼容。在已完成的CRS中，最首选的环境是无能量注入的ISM，SC，νm<；ν<；νc。我们的结果与以前通过无线电CRS测试标准火球模型的研究是一致的。
Gamma-Ray Bursts (GRBs) are panchromatic, highly energetic transients whose energy emission mechanism is still debated. One of the possible explanations is the standard fireball model, which can be tested with the closure relations (CRs), or relations between the temporal and spectral indices of a GRB. To test these, we compile an extensive sample of radio afterglow light curves (LCs) that span from 1997 to 2020, the most comprehensive analysis of GRBs with radio observations to date. We fit 202 LCs from 82 distinct GRBs with a broken power law, obtaining a sample of 26 that display a clear break and a subsample of 14 GRBs that present a radio plateau. We test these samples against CRs corresponding to a constant-density interstellar medium (ISM) or a stellar wind medium in both fast- and slow-cooling regimes, as well as three additional density profiles, k = 1, 1.5, 2.5, following n∝r−k, and consider sets of CRs both with and without energy injection. We find that 12 of the 26 GRBs (46 per cent), of which 7/12 present a radio plateau, fulfill at least one CR in the sets tested, suggesting our data is largely incompatible with the standard fireball model. Of the fulfilled CRs, the most preferred environment is the ISM, SC, νm < ν < νc without energy injection. Our results are consistent with previous studies that test the standard fireball model via the CRs in radio.