用Spitzer探测仙王座A East上的乙炔
Detection of Acetylene toward Cepheus A East with Spitzer
摘要：
第一张星际乙炔（C2 H2）的地图是用斯皮策太空望远镜上的红外光谱仪获得的。在仙王座A东的恒星形成区域，在13.7微米处的$ν_5$振动-旋转带的谱线图显示，C2 H2的发射峰值出现在少数几个局部的团块中，而这些团块是以前用斯皮策探测到的气相CO2发射。来自拟合C2 H2线配置文件的激发温度的分布范围从50到200 K，与来自气态CO2的范围一致，表明这两种分子探测相同的温暖的气体成分。C2 H2分子通过从HW 2原恒星区域发出的13.7微米连续光子的辐射泵浦而被激发。我们得到的柱密度范围为几× 10^13 ~~ 7 × 10^14 cm^-2，对应的C2 H2相对于H2的丰度为1 × 10^-9 ~ 4 × 10^-8。随着大致恒定的N（C2 H2）/N（CO2）的C2 H2排放的空间分布强烈建议与冲击活动，最有可能的结果乙炔溅射在冰粒地幔。
英文摘要：
The first map of interstellar acetylene (C2H2) has been obtained with the infrared spectrograph onboard the Spitzer Space Telescope. A spectral line map of the $ν_5$ vibration-rotation band at 13.7 microns carried out toward the star-forming region Cepheus A East, shows that the C2H2 emission peaks in a few localized clumps where gas-phase CO2 emission was previously detected with Spitzer. The distribution of excitation temperatures derived from fits to the C2H2 line profiles ranges from 50 to 200 K, a range consistent with that derived for gaseous CO2 suggesting that both molecules probe the same warm gas component. The C2H2 molecules are excited via radiative pumping by 13.7 microns continuum photons emanating from the HW2 protostellar region. We derive column densities ranging from a few x 10^13 to ~ 7 x 10^14 cm^-2, corresponding to C2H2 abundances of 1 x 10^-9 to 4 x 10^-8 with respect to H2. The spatial distribution of the C2H2 emission along with a roughly constant N(C2H2)/N(CO2) strongly suggest an association with shock activity, most likely the result of the sputtering of acetylene in icy grain mantles.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
