论文标题
Herschel 158 $μ$ m [CII]在Perseus Giant Molecular Cloud中观察到“涂层”气
Herschel 158$ μ$m [CII] Observations of "CO-dark" Gas in the Perseus Giant Molecular Cloud
论文作者
论文摘要
我们介绍了速度分辨[CII] 158 $μ$ m从渗透巨型巨型分子云(GMC)中的密集和更漫射的光解离区(PDR)发射的观察结果,该速度是使用异差仪器用于Far-In-Frared Onboard Herschel Space TeleScope的。我们从总位置的80 \%检测[CII]发射,从密集边界区域的检测率为95 \%。尽管观察到1 MAG和10 MAG之间的光学灭绝范围,但[CII]发射的集成强度在每个边界之间保持相对恒定。这种平坦的轮廓表明在观察到的两个区域内都有恒定的加热和冷却速率。 [CII]发射的综合强度与中性氢(HI)柱密度以及总气柱密度相关。除了从云中心发出的[CII]发射的80 $'$(7 pc)之外,这表明,HI信封在解释珀尔修斯发出的[CII]发射方面起着主要作用。我们将[CII]和$^{12} $ CO集成强度与1-D双面平板PDR模型的预测进行了比较,并表明一个简单的核心$+$信封,平衡模型,没有其他“ Coy-Dark” H $ _2 $组件可以很好地重现观测值。需要进行其他观察结果,以解散[CII]发射的数量与“ Co-Dark” H $ _2 $气体相关,并约束跨珀斯修斯的尘埃与气体比例的空间变化。
We present observations of velocity-resolved [CII] 158 $μ$m emission from both a dense and a more diffuse photodissociation region (PDR) in the Perseus giant molecular cloud (GMC) using the Heterodyne Instrument for the Far-Infrared onboard the Herschel Space Telescope. We detect [CII] emission from 80\% of the total positions, with a 95\% detection rate from the dense boundary region. The integrated intensity of the [CII] emission remains relatively constant across each boundary, despite the observed range in optical extinction between 1 mag and 10 mag. This flat profile indicates a constant heating and cooling rate within both regions observed. The integrated intensity of [CII] emission is reasonably well correlated with the neutral hydrogen (HI) column density, as well as total gas column density. This, in addition to the 80$'$ (7 pc) extent of the [CII] emission from cloud center, suggests that the HI envelope plays a dominant role in explaining the [CII] emission emanating from Perseus. We compare the [CII] and $^{12}$CO integrated intensities with predictions from a 1-D, two-sided slab PDR model and show that a simple core $+$ envelope, equilibrium model without an additional "CO-dark" H$_2$ component can reproduce observations well. Additional observations are needed to disentangle how much of the [CII] emission is associated with the "CO-dark" H$_2$ gas, as well as constrain spatial variations of the dust-to-gas ratio across Perseus.