标题： 一个亚太阳Fe/O、logT~7.5的气体成分渗透银河系的CGM 显示英文标题

标题： A Sub-solar Fe/O, logT~7.5 Gas Component Permeating the Milky Way's CGM

摘要： 我们的研究集中于描述银河系（MW）星系际介质（CGM）中的高电离气体，这些气体在X射线波段 2 - 25 \AA 中产生离子跃迁。通过利用指向类星体视线的叠加 \Chandra /\ACISS \MEG 和 \LETG 光谱，我们使用自洽混合电离代码PHASE来模拟我们的数据。 叠层光谱的最佳描述由三个不同的气相组分组成：一个 \warm (\logT $\sim$ 5.5)，\warmhot \ (\logT $\sim 6$ ) 和 \hot (\logT $\sim$ 7.5) 组分。 这些发现证实了在银河系CGM中存在\hot 成分，表明它与\warm 和\warmhot 气相共存。 我们发现该\hot 成分在温度上是均匀的，但在柱密度上是不均匀的。 \hot 成分中的气体需要相对于太阳有过多丰度才能与文献中报道的银河晕的色散度（DM）一致。 {对于高温相，我们估计 DM = $55.1^{+29.9}_{-23.7}$ pc cm$^{-3}$}。 我们得出结论，这一相要么富含氧、硅和硫，要么金属丰度达到太阳值的{超过 6}倍，或者两者兼而有之。 我们没有探测到 Fe L 边吸收线，意味着 O/Fe >$\geq$ 4。在银河晕超临界气体组分中发现的非太阳丰度比表明，这一相态是由星系反馈产生的。 显示英文摘要

摘要： Our study focuses on characterizing the highly ionized gas within the Milky Way's (MW) Circumgalactic Medium (CGM) that gives rise to ionic transitions in the X-ray band 2 - 25 \AA. Utilizing stacked \Chandra/\ACISS\ \MEG\ and \LETG\ spectra toward QSO sightlines, we employ the self-consistent hybrid ionization code PHASE to model our data. The stacked spectra are optimally described by three distinct gas phase components: a \warm\ (\logT\ $\sim$ 5.5), \warmhot\ (\logT\ $\sim 6$), and \hot\ (\logT\ $\sim$ 7.5) components. These findings confirm the presence of the \hot\ component in the MW's CGM indicating its coexistence with a \warm\ and a \warmhot\ gas phases. We find this \hot\ component to be homogeneous in temperature but inhomogeneous in column density. The gas in the \hot\ component requires over-abundances relative to solar to be consistent with the Dispersion Measure (DM) from the Galactic halo reported in the literature. {For the hot phase we estimated a DM = $55.1^{+29.9}_{-23.7}$ pc cm$^{-3}$}. We conclude that this phase is either enriched in Oxygen, Silicon, and Sulfur, or has metallicity {over 6} times solar value, or a combination of both. We do not detect Fe L-shell absorption lines, implying O/Fe $\geq$ 4. The non-solar abundance ratios found in the super-virial gas component in the Galactic halo suggest that this phase arises from Galactic feedback.