Betz A L, Boreiko R T
Space Sciences Laboratory, University of California, USA.
Astrophys J. 1989 Nov 15;346(2):L101-4. doi: 10.1086/185589.
The fundamental OH rotational transition at 2514 GHz (119.2 micrometers) has been observed in the Orion IRc2 region at a spectral resolution of 0.6 km s-1. The emission is spatially compact (< 25" FWHM) and centered near IRc2. A comparison of the observed profile with spectra of other species known to exist in the region suggests that the entire blueshifted side of the OH profile has been "self-absorbed," leaving only a redshifted emission component. In addition, there is pronounced absorption near 5 km s-1 VLSR indicative of the "hot core" source. The presence of the 119 micrometers absorption provides a straightforward explanation for the high ratio of 163/119 micrometers integrated line intensities which was previously considered anomalous.
在猎户座IRc2区域以0.6千米每秒的光谱分辨率观测到了2514吉赫兹（119.2微米）处的基本OH转动跃迁。发射在空间上紧凑（半高宽<25"），且以IRc2为中心。将观测到的谱线轮廓与该区域已知存在的其他物种的光谱进行比较表明，OH谱线轮廓的整个蓝移侧已被“自吸收”，仅留下一个红移发射分量。此外，在本地标准速度（VLSR）5千米每秒附近有明显的吸收，这表明存在“热核”源。119微米吸收的存在为先前被认为异常的163/119微米积分线强度的高比值提供了一个直接的解释。
