标题： 猎户座OMC-1核心的延展远红外CO发射 显示英文标题

标题： Extended Far-Infrared CO Emission in the Orion OMC-1 Core

摘要： 我们报道了猎户座OMC-1核心中$^{12}$CO纯转动跃迁的高灵敏度远红外观测结果。这些谱线是在红外空间天文台（ISO）上的长波光谱仪（LWS）的光栅模式下观测的，覆盖了43-197$\mu$微米的波长范围。从$J_{up}=14$到$J_{up}=19$的跃迁在整个OMC-1核区内被识别出来，并且在中心区域KL/IRc2检测到了高达$J_{up}= 43$的跃迁。此外，我们还使用Fabry-Perot模式获取了一些CO谱线的高质量光谱。在KL/IRc2区域，三条温度模型可以很好地解释平台和脊发射的线状特征。 高能级$J$跃迁中检测到的流量 ($J_{up} > 34$) 表明存在非常炽热且密集的气体组分（温度为$T=1500-2500$千克；$\rm N(CO)$=2\times × 10^{17}\cmmd $), probably originating from some of the embedded sources previously observed in the $\rm H_2$ near-infrared lines. At all other positions in the OMC-1 core, we estimate kinetic temperatures $\geq 80 K，并且在某些 IRc2 周围的位置高达 150 K，基于一个简单的大速度梯度模型）。 显示英文摘要

摘要： We report on sensitive far-infrared observations of $^{12}$CO pure rotational transitions in the OMC-1 core of Orion. The lines were observed with the Long Wavelength Spectrometer (LWS) in the grating mode on board the Infrared Space Observatory (ISO), covering the 43-197 $\mu$m wavelength range. The transitions from $J_{up}=14$ up to $J_{up}=19$ have been identified across the whole OMC-1 core and lines up to $J_{up}= 43$ have been detected towards the central region, KL/IRc2. In addition, we have taken high-quality spectra in the Fabry-Perot mode of some of the CO lines. In KL/IRc2 the lines are satisfactorily accounted for by a three-temperature model describing the plateau and ridge emission. The fluxes detected in the high-$J$ transitions ($J_{up} > 34$) reveal the presence of a very hot and dense gas component ($T=1500-2500$ K; $\rm N(CO)$=2\times 10^{17}\cmmd$), probably originating from some of the embedded sources previously observed in the $\rm H_2$ near-infrared lines. At all other positions in the OMC-1 core, we estimate kinetic temperatures $\geq 80$ K and as high as 150 K at some positions around IRc2, from a simple Large-Velocity Gradient model.