Circinus的核尘埃带：无环面准直
The nuclear dust lane of Circinus: collimation without a torus
摘要：
在某些活动星系核中，连接到kpc尺度尘埃结构的核尘埃带提供了掩盖核所需的所有消光，挑战了统一模型提出的尘埃环的作用。在这封信中，我们显示了pc规模的尘埃和电离气体的Circinus地图，使用亚弧秒精度注册的红外VLT AO图像与光学\textit{Hubble Space Telescope}图像。我们发现电离气体的准直不需要环面，而是由宿主星系的尘埃带在$\sim$ 10 pc尺度上的分布引起的。这一发现质疑了假定的环面形态及其在秒差距尺度上的作用，因为它的主要属性之一是准直核辐射，并且与干涉观测结果一致，干涉观测结果表明大多数pc尺度的尘埃都在极向。我们估计，圆规座的核尘埃带提供了掩盖原子核所需的消光的$1/3$。这构成了中央秒差距处的遮蔽度的保守下限，如果尘埃丝是将物质从$\sim$ 100 pc尺度输送到中央的通道，那么尘埃丝在光学上可能会变得更厚。
英文摘要：
In some AGN, nuclear dust lanes connected to kpc-scale dust structures provide all the extinction required to obscure the nucleus, challenging the role of the dusty torus proposed by the Unified Model. In this letter we show the pc-scale dust and ionized gas maps of Circinus constructed using sub-arcsec-accuracy registration of infrared VLT AO images with optical \textit{Hubble Space Telescope} images. We find that the collimation of the ionized gas does not require a torus but is caused by the distribution of dust lanes of the host galaxy on $\sim$10 pc scales. This finding questions the presumed torus morphology and its role at parsec scales, as one of its main attributes is to collimate the nuclear radiation, and is in line with interferometric observations which show that most of the pc-scale dust is in the polar direction. We estimate that the nuclear dust lane in Circinus provides $1/3$ of the extinction required to obscure the nucleus. This constitutes a conservative lower limit to the obscuration at the central parsecs, where the dust filaments might get optically thicker if they are the channels that transport material from $\sim$100 pc scales to the centre.
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。
