长的去极化H $α$ -细丝朝向Monogem环
Long, depolarising H$α$-filament towards the Monogem ring
摘要：
在软X射线中，Monogem环是一个位于银河系反中心的直径为25°的物体。它被认为是一个微弱的，进化的，局部超新星遗迹。环在远紫外线下也可见，一些光学细丝也与之相关。它不像其他大型超新星遗迹那样在无线电波段被观测到。我们研究了一条长约4.5°的窄的、微弱的H $α$ -细丝G203.7+ 11.5，它位于Monogem环的中心。它导致去极化和过度法拉第旋转的无线电偏振数据。分析了使用Effelsberg 100-m望远镜在$λ$ 11 cm和$λ$ 21 cm处进行的偏振观测。除了$WMAP$数据、河外自转测量和H $α$数据之外。采用法拉第屏模型。通过对H $α$灯丝退极化特性的分析，我们导出了在300 μ c距离上的视线磁场$B_{||}$为26 $\pm5μ$ G，电子密度$n_\mathrm{e}$为1.6 cm $^{-3}$ . G203.7+11.5的绝对最大自转量为-86 $\pm3$ ~rad~ m $^{-2}$，磁场方向与大尺度银河场的符号相反。我们估算了在$λ$ 21 cm至300 pc距离处，G203.7+11.5的平均同步辐射发射率约为1.1 K $T_\mathrm{b}$ /kpc，高于典型的银河系值。G203.7+11.5内的磁场在方向和强度上出乎意料。最有可能的是，暗条与Monogem环激波有关，与周围云层的相互作用可能导致局部磁场逆转。我们证实了早期的研究结果，增强，但方向相关的本地同步辐射率。
英文摘要：
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.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
