AKARI NEAR-INFRARED SPECTROSCOPIC SURVEY FOR COMETARY VOLATILES
AKARI NEAR-INFRARED SPECTROSCOPIC SURVEY FOR COMETARY VOLATILES
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DOI：
10.5303/pkas.2012.27.4.161
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发表时间：
2012-09
期刊：
影响因子：
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通讯作者：
T. Ootsubo;H. Kawakita;H. Kobayashi;F. Usui;A. team
中科院分区：
文献类型：
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作者：
T. Ootsubo;H. Kawakita;H. Kobayashi;F. Usui;A. team
我们用日本红外卫星AKARI上的红外相机对彗星挥发物进行了光谱调查。观测时间为2008年6月至2010年1月，在近红外波长范围内进行。本文总结了AKARI对彗星主要挥发物混合比的观测和结果。我们推导出了2.5？5 .奥尔特云彗星和木星家族彗星等18颗彗星的um光谱。观测到的光谱中突出的发射波段是水（H₂O）在2.7¹m和二氧化碳（CO₂）在4.3 um的基本振动波段。在一些彗星上，在3.4 ~ 3.5 μ m范围内，也可以识别出在4.7 μ m范围内的一氧化碳（CO）的基本振动带和可能与含C-H分子有关的宽发射特征。我们在18颗彗星中检测到了17颗彗星的CO₂，并得出了17颗彗星中CO₂与H₂O的产气率比。我们只在三颗彗星上发现了可靠的CO发射带。我们的数据集提供了迄今为止获得的彗星CO₂/H₂O比率的最大同构数据库。
We performed a spectroscopic survey for cometary volatiles with the Infrared Camera onboard the Japanese infrared satellite AKARI. The observations were carried out in the near-infrared wavelength range in the period from 2008 June to 2010 January. In this paper, we summarize the observations and results of the AKARI survey for the mixing ratios of major volatiles in comets. We derived the 2.5?5 ㎛ spectra of 18 comets including both Oort cloud comets and Jupiter-family comets. Prominent emission bands in the observed spectra are the fundamental vibrational bands of water (H₂O) at 2.7 ¹m and carbon dioxide (CO₂) at 4.3 ㎛. The fundamental vibrational band of carbon monoxide (CO) at 4.7 ㎛ and the broad emission feature probably related to C-H bearing molecules can also be recognized around the 3.4?3.5 ㎛ region in some comets. We detect CO₂ in 17 out of 18 comets, and derived gas production rate ratios of CO₂ with respect to H₂O in 17 comets. We detect a reliable CO emission band only in three of the comets. Our data set provides the largest homogeneous database of CO₂/H₂O ratios in comets obtained so far.