Stringent upper limits to the solid NH3 abundance towards W 33A from near-IR spectroscopy with the Very Large Telescope
Stringent upper limits to the solid NH3 abundance towards W 33A from near-IR spectroscopy with the Very Large Telescope
复制标题
使用甚大望远镜的近红外光谱对 W 33A 的固体 NH3 丰度有严格的上限
DOI：
10.1051/0004-6361:20021798
复制
发表时间：
2003
影响因子：
6.5
通讯作者：
E. Dishoeck
中科院分区：
文献类型：
--
作者：
I. Taban;W. Schutte;K. Pontoppidan;E. Dishoeck
为了寻找星周冰的吸收特征，我们获得了1.9-2.5微米高质量年轻星体W33A的近红外光谱。在光谱中确定了CH3OH的2.27µmb和，其强度与先前从3.54和3.91微米的甲醇谱带得到的柱密度完全一致。另一方面，没有检测到2.21µmb和固体NH3。这表明，朝向W 33A的固体NH3的数量至少比先前基于9微米NH3伞形模式的估计低3倍。
We obtained near-infrared spectroscopy of the high mass young stellar object W 33A between 1.9-2.5 µm in search of absorption features of circumstellar ices. The 2.27 µ mb and of CH3OH is positively identified in the spectrum, its intensity being fully consistent with the column density derived earlier from the methanol bands at 3.54 and 3.91 µm. The 2.21 µ mb and of solid NH3, on the other hand, was not detected. This shows that the quantity of solid NH3 towards W 33A is at least 3 times lower than earlier estimates based on the NH3 umbrella mode at 9 µm.