Gamma-ray observations of MAXI J1820+070 during the 2018 outburst
Gamma-ray observations of MAXI J1820+070 during the 2018 outburst
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2018 年爆发期间 MAXI J1820 070 的伽马射线观测
DOI：
10.1093/mnras/stac2686
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发表时间：
2022
影响因子：
4.8
通讯作者：
Asano, K
中科院分区：
文献类型：
--
作者：
Abe, H;Abe, S;Acciari, V A;Aniello, T;Ansoldi, S;Antonelli, L A;Arbet Engels, A;Arcaro, C;Artero, M;Asano, K
MAXI J1820+070是一个低质量的x射线双星，黑洞（BH）是一个致密的物体。从2018年3月到10月，这颗双星经历了一次异常明亮的x射线爆发，在这整个时期，通过射电发射显示出非热粒子群的证据。本文介绍了MAXI J1820+070爆发的59.5 h的综合观测结果，包括高能200 GeV以上的H.E.S.S、MAGIC和VERITAS实验，以及0.1 ~ 500 GeV之间的fermi - lat数据，以及从射电到x射线的多波长观测。MAXI J1820+070没有探测到伽玛射线发射，但获得的上限和多波长数据使我们能够在有关非热粒子种群和射流同步加速器谱的合理假设下对源性质进行有意义的约束。特别是，有可能表明，如果在源的硬状态期间存在高能（HE）伽马射线发射区域，其预测通量应该最多比获得的费米- lat上限低20倍，并且在明显低于均分的磁场中更接近它们。在状态转换过程中，在电子被加速到~ 500 GeV的合理假设下，多波长数据和伽马射线上限一致地得出结论，即高能和极高能伽马射线发射区应该位于距离黑洞1011至1013cm之间的距离。在不久的将来，类似的低质量x射线双星爆发可能会被CTA等即将问世的仪器探测到。
MAXI J1820+070 is a low-mass X-ray binary with a black hole (BH) as a compact object. This binary underwent an exceptionally bright X-ray outburst from 2018 March to October, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 h of observations of the MAXI J1820+070 outburst with the H.E.S.S., MAGIC and VERITAS experiments at energies above 200 GeV are presented, together withFermi-LAT data between 0.1 and 500 GeV, and multiwavelength observations from radio to X-rays. Gamma-ray emission is not detected from MAXI J1820+070, but the obtained upper limits and the multiwavelength data allow us to put meaningful constraints on the source properties under reasonable assumptions regarding the non-thermal particle population and the jet synchrotron spectrum. In particular, it is possible to show that, if a high-energy (HE) gamma-ray emitting region is present during the hard state of the source, its predicted flux should be at most a factor of 20 below the obtainedFermi-LAT upper limits, and closer to them for magnetic fields significantly below equipartition. During the state transitions, under the plausible assumption that electrons are accelerated up to ∼500 GeV, the multiwavelength data and the gamma-ray upper limits lead consistently to the conclusion that a potential HE and very-HE gamma-ray emitting region should be located at a distance from the BH ranging between 1011and 1013cm. Similar outbursts from low-mass X-ray binaries might be detectable in the near future with upcoming instruments such as CTA.