Discovery of a New Gamma-Ray Source, LHAASO J0341+5258, with Emission up to 200 TeV
Discovery of a New Gamma-Ray Source, LHAASO J0341+5258, with Emission up to 200 TeV
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发现新的伽马射线源 LHAASO J0341 5258，发射高达 200 TeV
DOI：
10.3847/2041-8213/ac0fd5
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
T.
中科院分区：
文献类型：
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作者：
Zhen Cao;Felix Aharonian;Q. An;Axikegu;L. X. Bai;Y. Bai;Y. W. Bao;Denis Bastieri;X. J. Bi;Y. J. Bi;H. Cai;J. T. Cai;Zhe Cao;J. F. Chang;J. F. Chang;B. M. Chen;E. S. Chen;J. Chen;Liang Chen;Long Chen;M. J. Chen;M. L. Chen;Q. H. Chen;Sina Chen;S. Z. Chen;T.
我们报告发现了一个新的身份不明的扩展$伽玛$-射线源在银河系命名为LHAASO J 0341 +5258与审判前的意义为8.2标准偏差以上25 TeV。最佳拟合位置为R.A.$= 55.34^{circ}pm0.11^{circ}$和Dec$=52.97^{circ}pm0.07^{circ}$。LHAASO J 0341 +5258的角大小为0.29^circ_{stat} pm0.02^circ_{sys}$。25 TeV以上的能量流约为蟹状星云能量流的20%.虽然不排除从10 TeV到200 TeV的光谱与光子指数$alpha=2.98 pm 0.19_{stat} pm 0.02_{sys}$的幂律拟合，但LHAASO数据以及费米LAT观测设定的10 GeV处的通量上限，表明在大约50 TeV处截止初始硬幂律谱%（$alpha leq 1.75$）谱的明显变陡。我们简要地讨论了UHE γ射线的起源。在LHAASO J 0341 +5258内部或附近缺乏高能脉冲星和年轻的SNR是一个挑战，但并不排除产生伽马射线的轻子和强子场景。
We report the discovery of a new unidentified extended $gamma$-ray source in the Galactic plane named LHAASO J0341+5258 with a pre-trial significance of 8.2 standard deviations above 25 TeV. The best fit position is R.A.$=55.34^{circ}pm0.11^{circ}$ and Dec$=52.97^{circ}pm0.07^{circ}$. The angular size of LHAASO J0341+5258 is $0.29^circ pm 0.06^circ_{stat} pm0.02^circ_{sys}$. The flux above 25 TeV is about $20%$ of the flux of Crab Nebula. Although a power-law fit of the spectrum from 10 TeV to 200 TeV with the photon index $alpha=2.98 pm 0.19_{stat} pm 0.02_{sys}$ is not excluded, the LHAASO data together with the flux upper limit at 10 GeV set by the Fermi LAT observation, indicate a noticeable steepening of an initially hard power-law spectrum %($alpha leq 1.75$) spectrum with a cutoff at $approx 50$ TeV. We briefly discuss the origin of UHE gamma-rays. The lack of an energetic pulsar and a young SNR inside or in the vicinity of LHAASO J0341+5258 challenge, but do not exclude both the leptonic and hadronic scenarios of gamma-ray production.