Tercero B, Cernicharo J, López A, Brouillet N, Kolesniková L, Motiyenko R A, Margulès L, Alonso J L, Guillemin J-C
Grupo de Astrofísica Molecular. Instituto de CC. de Materiales de Madrid (ICMM-CSIC). Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049 Madrid, Spain.
Grupo de Astrofísica Molecular. Instituto de CC. de Materiales de Madrid (ICMM-CSIC). Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049 Madrid, Spain ; Dpto. de Astrofísica, CAB, INTA-CSIC, Crta Torrejón-Ajalvir, km 4, 28850 Torrejón de Ardoz, Madrid, Spain.
Astron Astrophys. 2015 Oct 1;582. doi: 10.1051/0004-6361/201526255.
We report on the tentative detection of trans ethyl methyl ether (tEME), t-CHCHOCH, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CHCHCHOH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 10 cm and ≤(1.0 ± 0.2)× 10 cm for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CHOCOH, CHCHOCOH, CHOCH, CHOH, and CHCHOH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio (CHOCH)/(tEME) ≥ 150 in the compact ridge of Orion.
我们报告了通过识别朝向猎户座KL分子的每个自旋态的大量转动谱线，初步探测到反式乙基甲基醚（tEME，t-CH3CH2OCH3）。我们还在同一源中搜索了tEME的异构体gauche-反式-n-丙醇（Gt-n-CH3CH2CH2OH）。我们在IRAM 30米谱线巡天和阿塔卡马大型毫米/亚毫米阵列（ALMA）科学验证数据中识别出了这两种物质的谱线。我们获得了ALMA地图以确定这些物质的空间分布。tEME主要源自猎户座的致密脊成分，而Gt-n-丙醇出现在乙醇的发射峰值处（南热核）。在它们发射峰值位置，这些物质的推导柱密度分别为tEME≤(4.0±0.8)×1014厘米-2和Gt-n-丙醇≤(1.0±0.2)×1014厘米-2。两种分子的转动温度均约为100K。我们还提供了CH3OCHO、CH3CH2OCHO、CH3OCH3、CH3OH和CH3CH2OH的地图，以比较该区域中这些含甲基和乙基的有机饱和含氧物种的分布。提供了相关物种的丰度比以及未检测到的醚类丰度的上限。我们推导在猎户座致密脊中丰度比(CH3OCH3)/(tEME)≥150。
