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arXiv 2404.02119astro-ph.GA
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船底座柱体的气体运动学与动力学:G287.76-0.87 的个案研究

Gas kinematics and dynamics of Carina Pillars: A case study of G287.76-0.87

Ngo-Duy Tung, Le Ngoc Tram, Archana Soam, William T. Reach, Edwin Das, Ed Chambers, Blesson Mathew

AI总结:

本文利用 SOFIA/GREAT 的多条 CO 和 [OI] 谱线研究船底座柱体 G287.76-0.87 的运动学与物理性质,发现其相对电离源速度小、尾部更湍流,并通过 LTE 与非 LTE 分析约束柱体密度和稳定性,揭示星风雕刻分子云形成柱体的机制。

摘要:

我们利用 SOFIA/GREAT 在船底座南部观测到的三条转动谱线 $^{12}$CO(5-4)、$^{12}$CO(8-7)、$^{12}$CO(11-10) 以及一条 [OI] $63\\,\mu$m 精细结构线,研究柱体 G287.76-0.87 的运动学。该柱体受到包含 $\eta$ Carinae 的大质量星团 Trumpler 16 的辐射照射。我们的分析表明,柱体相对于该电离源的速度很小,约为 $\sim 1\\,\rm km\\,s^{-1}$,并且尾部气体运动比头部更具湍流性。我们还进行了解析计算,以估计局部热动平衡(LTE)条件下的气体柱密度,得到 $N_{\rm CO}$ 为 $(\sim 0.2 -5)\times 10^{17}\\,\rm cm^{-2}$。我们进一步利用 RADEX 在非 LTE 条件下约束气体的物理性质。非 LTE 估计结果为 $n_{\rm H_{2}} \simeq 10^{5}\\,\rm cm^{-3}$ 和 $N_{\rm CO} \simeq 10^{16}\\,\rm cm^{-2}$。我们发现,如果恒星风不活跃,G287.76-0.87 柱体内的热压足够高,使其能够抵抗周围热气体和辐射反馈而保持稳定。当恒星风活跃时,来自成团恒星的星风将周围分子云雕刻成 $\eta$ Carinae 周围巨大气泡内的柱体。

英文摘要:

We study the kinematics of a pillar, namely G287.76-0.87, using three rotational lines of $^{12}$CO(5-4), $^{12}$CO(8-7), $^{12}$CO(11-10), and a fine structure line of [OI] $63\,μ$m Southern Carina observed by SOFIA/GREAT. This pillar is irradiated by the associated massive star cluster Trumpler 16, which includes $η$~Carina. Our analysis shows that the relative velocity of the pillar with respect to this ionization source is small, $\sim 1\,\rm km\,s^{-1}$, and the gas motion in the tail is more turbulent than in the head. We also performed analytical calculations to estimate the gas column density in local thermal equilibrium (LTE) conditions, which yields $N_{\rm CO}$ as $(\sim 0.2 -5)\times 10^{17}\,\rm cm^{-2}$. We further constrain the gas's physical properties in non-LTE conditions using RADEX. The non-LTE estimations result in $n_{\rm H_{2}} \simeq 10^{5}\,\rm cm^{-3}$ and $N_{\rm CO} \simeq 10^{16}\,\rm cm^{-2}$. We found that the thermal pressure within the G287.76-0.87 pillar is sufficiently high to make it stable for the surrounding hot gas and radiation feedback if the winds are not active. While they are active, stellar winds from the clustered stars sculpt the surrounding molecular cloud into pillars within the giant bubble around $η$~Carina.

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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