论文标题
彗星C/2016 R2的离子排放（Pan-Starrs）
Ionic emissions in comet C/2016 R2 (Pan-STARRS)
论文作者
论文摘要
我们对印度印度阿布山红外天文台的120万个望远镜上安装的低分辨率光谱仪进行了对奇特的彗星C/2016 R2（Pan-Starrs）的观察。该彗星在2018年1月的两个日期上观察到，当时它是以2.8 au为中心的距离。根据我们的观察结果，研究表明，与一般彗星光谱相比，该彗星的光谱非常不寻常。大多数主要的彗星排放量，例如C $ _ {2} $，C $ _ {3} $，CON c/2016 R2中不存在CN。但是，彗星光谱显示出来自离子物种的非常强大的发射带，例如co $^{+} $和n $ _ {2}^{+} $。平均n $ _ {2} $/CO比率为0.09 $ \ pm $ 0.02，源自光谱，与太阳星云相比，该比率的极低耗尽因子为1.6 $ \ pm $ 0.4。我们还检测到了超过5400埃埃斯特罗姆的较小排放特征，尽管略有。 Co $^{+} $和n $ _ {2}^{+} $的列密度是从其发射带计算的。光谱表明，与太阳星云相比，该彗星中的低消耗因子为n $ _ {2} $/co/co的低耗竭因子和彗星的异常频谱是在其早期太阳能nebula中形成的位置，与彗星的异常处理相比。
We carried out observations of a peculiar comet, C/2016 R2 (Pan-STARRS), using a low resolution spectrograph mounted on the 1.2m telescope at Mount Abu Infrared Observatory, India. The comet was observed on two dates in January 2018, when it was at a heliocentric distance of 2.8 AU. Study based on our observations revealed that the optical spectrum of this comet is quite unusual as compared to general cometary spectra. Most of the major cometary emissions like C$_{2}$, C$_{3}$ and CN were absent in comet C/2016 R2. However, the comet spectrum showed very strong emission bands from ionic species like CO$^{+}$ and N$_{2}^{+}$. A mean N$_{2}$/CO ratio of 0.09 $\pm$ 0.02 was derived from the spectra and an extremely low depletion factor of 1.6 $\pm$ 0.4 has been estimated for this ratio as compared to the solar nebula. We have also detected minor emission features beyond 5400 Angstroms, albeit marginally. The column densities of CO$^{+}$ and N$_{2}^{+}$ were calculated from their emission bands. The optical spectrum suggests that the cometary ice is dominated by CO. The low depletion factor of N$_{2}$/CO ratio in this comet, as compared to the solar nebula and the unusual spectrum of the comet are consequences of distinctive processing at the location of its formation in the early solar nebula.
