论文标题
寻找融合原子气的融合流到分子云
Searching for converging flows of atomic gas onto a molecular cloud
论文作者
论文摘要
我们介绍了使用板上索非亚的升级仪器从孤立的分子云中进行[CII]良好结构线发射的新观察结果。将这些数据与档案CO = 1-0和HI 21 cm发射光谱一起分析，以研究收敛的原子气流在形成分子云中的作用。在整个映射区域中检测到明亮的[CII]发射，这可能起源于云中新生儿产生的紫外线辐射场激发的光解离区域。在[CII]光谱的空间平均值时，我们在速度间隔内确定了弱的[CII]发射，其中HI 21 cm线最亮。这些是相对于CO的速度和明亮[CII]发射4 km/s的蓝班。亮度温度，速度分散和与HI 21 cm速度的对齐，将此[CII]发射成分连接到星际培养基（CNM）的冷的中性原子气体。我们建议此CNM特征是进入现有分子云的远处的积聚流。质量输入率为3.2x10 ** { - 4} msun/yr。没有直接的证据表明[CII]或HI 21 cm光谱线中有可比的红移成分，这表明会聚流的存在。
We present new observations of [CII] fine structure line emission from an isolated molecular cloud using the upGREAT instrument onboard SOFIA. These data are analyzed together with archival CO=1-0 and HI 21 cm emission spectra to investigate the role of converging atomic gas flows in the formation of molecular clouds. Bright [CII] emission is detected throughout the mapped area that likely originates from photodissociation regions excited by UV radiation fields produced by newborn stars within the cloud. Upon spatial averaging of the [CII] spectra, we identify weak [CII] emission within velocity intervals where the HI 21 cm line is brightest; these are blue-shifted relative to velocities of the CO and bright [CII] emission by 4 km/s. The brightness temperatures, velocity dispersions, and alignment with HI 21 cm velocities connect this [CII] emission component to the cold, neutral atomic gas of the interstellar medium (CNM). We propose that this CNM feature is an accretion flow onto the far--side of the existing molecular cloud. The mass infall rate is 3.2x10**{-4} Msun/yr. There is no direct evidence of a comparable red--shifted component in the [CII] or HI 21 cm spectral lines that would indicate the presence of a converging flow.
