HAWC Search for High-mass Microquasars
HAWC Search for High-mass Microquasars
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DOI：
10.3847/2041-8213/abf35a
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发表时间：
2021-01
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通讯作者：
A. Albert;R. Alfaro;C. Álvarez;J. Angeles Camacho;J. C. Arteaga-Velázquez;K. Arunbabu;D. Avila Rojas-D.-Avila
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作者：
A. Albert;R. Alfaro;C. Álvarez;J. Angeles Camacho;J. C. Arteaga-Velázquez;K. Arunbabu;D. Avila Rojas-D.-Avila
具有高质量伴星的微类星体是很有希望的极高能量（VHE; 0.1-100 TeV）伽马射线发射体，但它们在10 TeV以上的行为却知之甚少。利用高海拔水切伦科夫（HAWC）天文台，我们寻找多余的伽马射线发射与已知的高质量微类星体（HMMQs）的位置一致。在1523天的HAWC数据中，没有观察到LS 5039、Cyg X-1、Cyg X-3和SS 433的显著排放。我们设定了迄今为止在每个单独源上获得的10 TeV以上的最严格限制。假设HMMQs通过一个共同的机制产生伽马射线，我们已经进行了源堆叠搜索，考虑两种不同的情况：（I）伽马射线光度是微类星体喷流光度的一个分数，（II）VHE伽马射线是由相对论电子在磁场B中向上散射伴星星星的辐射场产生的。我们得到的情形I的γ < 5.4 × 10−6，这严格限制了HMMQs可观测到高能中微子发射的模型。在第二种情况下，VHE伽马射线的未检测产生一个强磁场，这挑战了同步辐射作为10 keV和10 MeV之间的微类星体发射的主导机制。
Microquasars with high-mass companion stars are promising very high energy (VHE; 0.1–100 TeV) gamma-ray emitters, but their behaviors above 10 TeV are poorly known. Using the High Altitude Water Cerenkov (HAWC) observatory, we search for excess gamma-ray emission coincident with the positions of known high-mass microquasars (HMMQs). No significant emission is observed for LS 5039, Cyg X-1, Cyg X-3, and SS 433 with 1523 days of HAWC data. We set the most stringent limit above 10 TeV obtained to date on each individual source. Under the assumption that HMMQs produce gamma rays via a common mechanism, we have performed source-stacking searches, considering two different scenarios: (I) gamma-ray luminosity is a fraction ϵ γ of the microquasar jet luminosity, and (II) VHE gamma rays are produced by relativistic electrons upscattering the radiation field of the companion star in a magnetic field B. We obtain ϵ γ < 5.4 × 10−6 for scenario I, which tightly constrains models that suggest observable high-energy neutrino emission by HMMQs. In the case of scenario II, the nondetection of VHE gamma rays yields a strong magnetic field, which challenges synchrotron radiation as the dominant mechanism of the microquasar emission between 10 keV and 10 MeV.