论文标题
North Polar Spur/Loop I：北部费米泡沫的巨大郊区或附近被超新星吹动的热气腔？
North Polar Spur/Loop I: gigantic outskirt of the Northern Fermi bubble or nearby hot gas cavity blown by supernovae?
论文作者
论文摘要
银河系的无线电连续体，微波和伽马射线图像揭示了一个引人注目的，类似环的结构，几乎填充了北银半球的一半，称为Loop I。循环I的内部I内部在柔软的X射线中闪耀，其东部底座是一个明亮的，细长的结构。经过40年的辩论，仍然捍卫了循环I/NP的两个矛盾的观点：一方面，NPS是扩展的热气量，它包裹着并扩展了北部费米气泡（FB）已知被银河中心吹动的北部泡沫（FB），而Loop I标记了冲击阵线；另一方面，NPS是附近的Supernovae吹气的热气腔，Loop I是它的冲击阵线，它们恰好位于FB方向。对于在阳光下的观察者来说，两种结构都可以产生相同的视角，尽管前者的大小与银河系本身相当，而后者的直径为几百个parsecs。所涉及的能量的变化为3-4〜数量级，该解决方案具有各种重要的后果。我讨论了与循环I/NP有联系的最新结果，该结果以两种相反的方式被忽略或用作参数。它们涉及非常不同的航天器，从12千克立方体（Halosat）到主要的太空观测站（HST，Gaia和Spektr-RG）。我使用3D〜尘埃地图和巨大的星形目录。考虑到所有限制，很明显，没有完全局部或完全遥远的场景与某些数据分析或不可能的巧合无矛盾。我讨论了一种投机性场景，部分灵感来自最近的BF和银河系气模型，结合了近外的方面，似乎能够满足各种约束。但是，需要新的数据和模型来结束争议，我们仍然可以期待这一长篇小说的新剧集。
Radio continuum, microwave and gamma-ray images of the Milky Way reveal a conspicuous, loop-like structure that fills almost half of the northern Galactic hemisphere, called Loop I. The interior of Loop I is shining in soft X-rays, and its eastern base is a bright, elongated structure dubbed the North Polar Spur (NPS). After 40 years of debates, two contradictory views of Loop I/NPS are still defended: on the one hand, the NPS is a volume of expanding hot gas that envelops and extends the northern Fermi Bubble (FB) known to be blown by the Galactic center, and Loop I marks the shock front; on the other hand, the NPS is a nearby cavity of hot gas blown by supernovae, Loop I is its shock front and they are coincidentally located in the direction of the FB. To an observer at the Sun, both structures can produce the same perspective view, although the former has a size comparable to the Milky Way itself, and the latter a diameter of a few hundreds parsecs. The energy involved varies by 3-4~orders of magnitude, and the solution has various important consequences. I discuss recent results which have a connection with Loop I/NPS, overlooked or used as arguments in the two opposite ways. They involve very different spacecraft, from a 12 Kg Cubesat (HaloSat) to major space-borne observatories (HST, Gaia, and Spektr-RG). I make use of 3D~maps of dust and a massive star catalog. Considering all constraints, it is clear that there is no entirely local or entirely distant scenario that is free from contradictions with some of the data analyses or from improbable coincidences. I discuss a speculative scenario, partially inspired by recent BF and Milky Way gas models, combining near and far aspects and seeming to be able to meet the various constraints. However, new data and models are needed to bring the controversy to a close and we can still expect new episodes of this long story.
