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arXiv 1404.0403astro-ph.GA
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用赫歇尔空间天文台观测半人马座A盘中气体的物理特征

The physical characteristics of the gas in the disk of Centaurus A using the Herschel Space Observatory

T. J. Parkin, C. D. Wilson, M. R. P. Schirm, M. Baes, M. Boquien, A. Boselli, D. Cormier, M. Galametz, O. Ł. Karczewski, V. Lebouteiller, I. De Looze, S. C. Mad… 展开作者

T. J. Parkin, C. D. Wilson, M. R. P. Schirm, M. Baes, M. Boquien, A. Boselli, D. Cormier, M. Galametz, O. Ł. Karczewski, V. Lebouteiller, I. De Looze, S. C. Madden, H. Roussel, M. W. L. Smith, L. Spinoglio

摘要:

我们使用Herschel PACS和SPIRE光谱学来寻找半人马座A盘中原子精细结构线发射的变化。特别是我们观察到[C II](158 $μ$ m),[N II](122和205 $μ$ m),[O I](63和145 $μ$ m)和[O III](88 $μ$ m)谱线,它们都在光电离和光解离区冷却气体中起重要作用。我们确定([C II]+[O I] $_{63}$)/ $F_{TIR}$线比(气体加热效率的代表)在整个观察区域没有显示出显着的径向趋势,与其他附近星系的观察相反。我们确定,10 - 20%的观测到的[C II]发射起源于电离气体。我们的观测结果和PDR模型之间的比较表明,远紫外辐射场,$G_0$的强度,$10^{1.75}$和$10^{2.75}$之间的变化和氢核密度之间的变化$10^{2.75}$和$10^{3.75}$厘米$^{-3}$,没有显着的径向趋势,在这两个属性。在大设计螺旋星系M51和椭圆星系NGC 4125的发射线特性的背景下,Cen A中的气体似乎更具有典型盘状星系的特征,而不是椭圆星系。

英文摘要:

We search for variations in the disk of Centaurus A of the emission from atomic fine structure lines using Herschel PACS and SPIRE spectroscopy. In particular we observe the [C II](158 $μ$m), [N II](122 and 205 $μ$m), [O I](63 and 145 $μ$m) and [O III](88 $μ$m) lines, which all play an important role in cooling the gas in photo-ionized and photodissociation regions. We determine that the ([C II]+[O I]$_{63}$)/$F_{TIR}$ line ratio, a proxy for the heating efficiency of the gas, shows no significant radial trend across the observed region, in contrast to observations of other nearby galaxies. We determine that 10 - 20% of the observed [C II] emission originates in ionized gas. Comparison between our observations and a PDR model shows that the strength of the far-ultraviolet radiation field, $G_0$, varies between $10^{1.75}$ and $10^{2.75}$ and the hydrogen nucleus density varies between $10^{2.75}$ and $10^{3.75}$ cm$^{-3}$, with no significant radial trend in either property. In the context of the emission line properties of the grand-design spiral galaxy M51 and the elliptical galaxy NGC 4125, the gas in Cen A appears more characteristic of that in typical disk galaxies rather than elliptical galaxies.

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。

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