论文标题
长，去极化的h $α$ - 单凝圈
Long, depolarising H$α$-filament towards the Monogem ring
论文作者
论文摘要
在软X射线中，单凝结环是一个直径为25°的物体，位于银河抗中央。据信这是一个微弱的，进化的当地超新星残留物。该环在遥远的紫外线中也可见，并且一些光丝丝是相关的。在无线电波长中没有看到它，就像其他大型超新星残留物一样。我们研究了大约4.5°长，微弱的H $α$ fILAMENT，g203.7+11.5，这是在单元环的中心看到的。它导致射线化数据的去极化和过度的法拉第旋转。分析了$ 11 \ cm的两极分化观测值，$ 11 \ cm和$λ$ 21 \ cm与Effelsberg 100米望远镜进行了分析。除了$ wmap $数据，外乳外旋转措施和h $α$数据之外。应用了法拉第幕模型。根据对H $α$细丝的去极化属性的分析，我们得出了一个视线磁场，$ b_ {||} $，为26 $ \pm5μ$ g，距离为300〜PC和电子密度，$ n_ \ mathrm {e} $，1.6〜cm $ $ $ $^{ - 3} $。 G203.7+11.5的绝对最大旋转度量是-86 $ \ pm3 $ 〜rad〜m $ $^{ - 2} $，其中磁场方向的相反符号来自大型银河系。我们估计平均同步器发射率在$λ$ 21 \ cm高达300〜PC的距离为G203.7+11.5至约1.1〜K $ T_ \ Mathrm {B} $/KPC，其高于典型的乳Milky Way值。 G203.7+11.5中的磁场在方向和强度上是出乎意料的。最有可能的细丝与单元 - 环冲击有关，在这种冲击中，与环境云的相互作用可能会导致局部磁场逆转。我们证实了增强但依赖于方向的局部同步加速器发射率的早期发现。
In soft X-rays, the Monogem ring is an object with a diameter of 25° located in the Galactic anti-centre. It is believed to be a faint, evolved, local supernova remnant. The ring is also visible in the far-ultraviolet, and a few optical filaments are related. It is not seen at radio wavelengths, as other large supernova remnants are. We study a narrow about 4.5° long, faint H$α$-filament, G203.7+11.5,that is seen towards the centre of the Monogem ring. It causes depolarisation and excessive Faraday rotation of radio polarisation data. Polarisation observations at $λ$11\ cm and $λ$21\ cm with the Effelsberg 100-m telescope were analysed. in addition to $WMAP$ data, extragalactic rotation measures, and H$α$ data. A Faraday-screen model was applied. From the analysis of the depolarisation properties of the H$α$ filament, we derived a line-of-sight magnetic field, $B_{||}$, of 26$\pm5μ$G for a distance of 300~pc and an electron density, $n_\mathrm{e}$, of 1.6~cm$^{-3}$. The absolute largest rotation measure of G203.7+11.5 is -86$\pm3$~rad~ m$^{-2}$, where the magnetic field direction has the opposite sign from the large-scale Galactic field. We estimated the average synchrotron emissivity at $λ$21\ cm up to 300~pc distance towards G203.7+11.5 to about 1.1~K $T_\mathrm{b}$/kpc, which is higher than typical Milky Way values. The magnetic field within G203.7+11.5 is unexpected in direction and strength. Most likely, the filament is related to the Monogem-ring shock, where interactions with ambient clouds may cause local magnetic field reversals. We confirm earlier findings of an enhanced but direction-dependent local synchrotron emissivity.
