论文标题

椭圆星系NGC 5813的热气的化学和热结构

The Chemical and Thermal Structure of the Hot Atmosphere of the Elliptical Galaxy NGC 5813

论文作者

Chatzigiannakis, D., Simionescu, A., Mernier, F.

论文摘要

我们使用档案,深X射线观测值以及采用基于最新的原子线发射数据库的多温光谱模型,对Galaxy组NGC 5813中化学和热结构的强大表示形式进行了强大的表示。 NGC 5813具有非常轻松的形态,这使我们的目标的选择是为了研究AGN反馈在群体内培养基(IGRM)中的影响的有前途的候选人。我们的结果展示了沿该组的NE-SW方向的显着,扩展的分布,与该组中央星系中的超质量黑洞的方向相关,已知已知与IGRM相互作用。我们的分析表明,气体从集团的中心被提升为凉气的可能起源,尽管无法明确排除其他场景,例如原位冷却。关于IGRM的化学结构以及与以前的大量簇中的发现不同,我们没有发现来自中央AGN的喷气机/裂片最近的金属运输的证据。取而代之的是,整个组的元素丰度平均保持在太阳能附近。元素的分布似乎独立于半半径,方位角和气体的热力学,这表明IGRM已有效混合。丰度分布的大规模均匀性意味着NGC 5813中存在复杂的动力学过程,尽管它的整体松弛形态。过去的AGN反馈或遗传的过去事件可能是此背后的主要机制。

We present a robust representation of the chemical and thermal structure in the galaxy group NGC 5813 using archival, deep X-ray observations, and employing a multi-temperature spectral model based on up to date atomic line emission databases. The selection of our target is motivated by the fact that NGC 5813 has a very relaxed morphology, making it a promising candidate for the study of the AGN feedback's influence in the intra-group medium (IGrM). Our results showcase a prominent, extended distribution of cool gas along the group's NE-SW direction, correlating with the direction along which the supermassive black hole in the group's central galaxy is known to interact with the IGrM. Our analysis indicates gas being uplifted from the group's centre as the probable origin of the cool gas, although alternative scenarios, such as in-situ cooling can not be explicitly ruled out. Regarding the chemical structure of the IGrM, and unlike previous findings in massive clusters, we find no evidence for recent metal transport by jets/lobes from the central AGN. Instead, elemental abundances remain near Solar on average across the group. The distribution of elements appears to be independent of galactocentric radius, azimuth and the thermodynamics of the gas, suggesting that the IGrM has been efficiently mixed. The large scale uniformity of the abundance distribution implies the presence of complex dynamical processes in NGC 5813, despite its overall relaxed morphology. Past events of extreme AGN feedback or sloshing could be the primary mechanisms behind this.

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