发表机构
Nagoya University; Gifu University; Chiba University; University of Tsukuba; Konan University; Deutsches Elektronen-Synchrotron DESY（名古屋大学; 岐阜大学; 千叶大学; 筑波大学; 神户学院大学; 德国电子同步辐射中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用ALMA观测发现TeV γ射线源HESS J1023的喷流-弧CO云呈细丝状，结合磁流体动力学模型证实其为微类星体喷流的足迹，测得其宇宙线质子能量远超典型SNR，是银道面最强大的宇宙线加速器。
AI 中文摘要
TeV γ射线源HESS J1023-575（以下简称HESS J1023）是年轻大质量星团Westerlund 2附近最明亮的H.E.S.S.源之一。HESS J1023与其东西两侧的喷流-弧CO云在170秒差距（pc）范围内呈现出显著的位置对齐关系。我们利用ALMA对这些CO云进行了亚秒差距（sub-pc）尺度的观测，发现这些云由大量细丝状结构组成：在距离7.5千秒差距（kpc）处，这些丝状结构的宽度约为0.5 pc、长度为10-20 pc，且与喷流-弧轴线完美对齐。基于从γ射线源HESS J1023中心喷出的微类星体喷流的磁流体动力学模型，我们提出一种解释：这些细丝状云是微类星体喷流在HI气体上留下的足迹。该模型还能解释喷流云与弧云的差异，即两侧HI气体密度存在不同。通过CO和HI气体的密度以及γ射线光度，我们在强子机制下计算出宇宙线质子能量Wp为7×10^48 erg，这比TeV γ射线超新星遗迹（SNR）RX J1713.7-3946和RX J0852.0-4622中推导的能量大10倍。HESS J1023的活跃时间可能长达1-10百万年（Myr），明显长于SNR的宇宙线加速持续时间。因此，HESS J1023是一个相当于至少1000个SNR的杰出宇宙线源，可能是银道面中最强大的宇宙线（CR）加速器。HESS J1023中的一个高能致密源（可能是一个年龄为百万年级的黑洞或中子星）因严重消光而仍被遮蔽。
英文摘要
The TeV $γ$-ray source HESS J1023-575 (HESSJ 1023 hereafter) is one of the brightest H.E.S.S. sources near the young massive cluster Westerlund 2. HESS J1023 shows a remarkable positional alignment with the Jet and Arc CO clouds on its eastern and western sides over 170 pc length. We have carried out sub-pc scale observations of the CO clouds with ALMA and have discovered that the clouds consist of numerous thin filamentary features of $\sim$0.5 pc width and 10--20 pc length at distance of 7.5 kpc, which are well aligned with the Jet-Arc axis. Based on the magneto-hydrodynamical model of microquasar jets launched from {the center of the $γ$-ray source} HESS J1023-575, we present an interpretation that the thin filamentary clouds are the footprints of the microquasar jets on the HI gas. The model also explains the dissimilar Jet vs. Arc clouds in terms of HI density difference on each side. By using the density of the CO and HI gas and the $γ$-ray luminosity, we have calculated the cosmic ray proton energy $W_{\rm p}$ to be 7$\times$10$^{48}$ erg under the hadronic scheme, which is ten times larger than those derived in the TeV $γ$-ray SNRs RX J1713.7-3946 and RX J0852.0-4622. It is likely that HESS~J1023 has been active over 1-10 Myr, which is significantly longer than the duration of cosmic ray acceleration of the SNRs. HESS~J1023 is therefore an outstanding source of cosmic rays equivalent to at least 1000 SNRs, and is possibly the most powerful CR accelerator in the Galactic disk. A high energy compact source in HESS~J1023, which is likely a Myr-old black hole or neutron star, remains veiled due to heavy extinction.
Comments6 pages, 3 figures, 1 table. Accepted for publication in PASJ as a Letter
