论文标题
朝向银河中心方向的巨大年轻恒星物体的近红外光谱：XCN和芳香族C-D特征
Near-infrared spectroscopy of a massive young stellar object in the direction toward the Galactic Center: XCN and aromatic C-D features
论文作者
论文摘要
我们报告了近红外（2.5--5微米）的近红外（〜30 arcsec）光谱，该光谱是朝向银河中心的方向的年轻恒星物体的光谱，并带有Akari卫星的红外摄像头。建议根据其非常红色和近距离位置，建议目前的目标为AFGL 2006。光谱显示出H $ _2 $ O和CO $ _2 $ ICE的强大吸收特征，以及HI BR Alpha重组线的发射和3.3微米频带，后者的后者源自多环状芳族烃（PAHS）或包含PAH的材料。该光谱在4.65微米处显示出广泛，复杂的吸收特征，这是通过CO ICE，CO GAS和XCN和HI PF Beta发射的吸收特征的结合来很好地解释的。光谱还表明在4.4微米处发射过量。光谱的特征表明该物体是一个庞大的年轻恒星物体。 XCN特征与BRα发射有良好的相关性，这表明紫外光子的光解在XCN载体的形成中起着重要作用，其中一部分归因于OCN $^ - $。 4.4微米的发射与3.3微米PAH的发射有良好的相关性，提供了证据表明它来自芳香族C-D拉伸振动。 OCN $^ - $的形成对于星际培养基（ISM）中益生元物质的形成过程至关重要，而芳香族C-D发射的检测为ISM中PAHS的剥离过程提供了有价值的信息，并涉及ISM中缺失氘核的隐藏地点的含义。
We report near-infrared (2.5--5 micron) long-slit (~ 30 arcsec) spectroscopy of a young stellar object in the direction toward the Galactic center with the Infrared Camera on board the AKARI satellite. The present target is suggested to be AFGL 2006 based on its very red color and close location. The spectra show strong absorption features of H$_2$O and CO$_2$ ices, and emission of HI Br alpha recombination line and the 3.3 micron band, the latter of which originates from polycyclic aromatic hydrocarbons (PAHs) or materials containing PAHs. The spectra show a broad, complex absorption feature at 4.65 micron, which is well explained by a combination of absorption features of CO ice, CO gas, and XCN, and HI Pf beta emission. The spectra also indicate excess emission at 4.4 micron. The characteristics of the spectra suggest that the object is a massive young stellar object. The XCN feature shows a good correlation with the Br alpha emission, suggesting that the photolysis by ultraviolet photons plays an important role in the formation of the XCN carriers, part of which are attributed to OCN$^-$. The 4.4 micron emission shows a good correlation with the 3.3 micron PAH emission, providing supporting evidence that it comes from the aromatic C-D stretching vibration. The formation of OCN$^-$ is of importance for the formation process of prebiotic matter in the interstellar medium (ISM), while the detection of aromatic C-D emission provides valuable information on the deuteration process of PAHs in the ISM and implications on the hiding site of the missing deuterium in the ISM.
