泰坦的多产丙烷：卡西尼CIRS透视
Titan's Prolific Propane: The Cassini CIRS Perspective
摘要：
在本文中，我们选择了大光谱平均数据从卡西尼复合红外光谱仪（CIRS）在临边观察模式在低纬度（30 S-30 N），大大增加了路径长度，因此信噪比光学薄微量物质，如丙烷。通过建模和减去其他气体物种的排放量，我们证明，至少有六个红外波段的丙烷检测CIRS，包括两个以前没有确定的泰坦光谱。利用1300- 1400 cm-1范围内的一个新的线表，以及现有的GEISA表，我们从748和1376 cm-1两个波段反演丙烷丰度。在748 cm-1处，我们在2 mbar下检索到4.2 +/- 0.5 x 10（-7）（1-sigma误差），与以前的研究非常一致，尽管目前的光谱图谱中缺乏热带仍然是一个问题。我们还在2 mbar下从1376 cm-1波段确定了5.7 +/- 0.8 x 10（-7）-该值可能受到系统误差的影响，包括由于霾引起的连续梯度以及乙烷n6波段的不完美模型。这项研究首次清楚地表明了泰坦热红外光谱中丙烷发射带的普遍性，并指出迫切需要进一步的实验室光谱学工作，以提供模拟这些波段所需的线位置和强度，并进一步表征霾光谱不透明度。目前缺乏准确的建模能力，丙烷是一个障碍，不仅为丙烷本身的测量，但也为寻找新的分子在许多光谱区域的排放。
英文摘要：
In this paper we select large spectral averages of data from the Cassini Composite Infrared Spectrometer (CIRS) obtained in limb-viewing mode at low latitudes (30S--30N), greatly increasing the path length and hence signal-to-noise ratio for optically thin trace species such as propane. By modeling and subtracting the emissions of other gas species, we demonstrate that at least six infrared bands of propane are detected by CIRS, including two not previously identified in Titan spectra. Using a new line list for the range 1300-1400cm -1, along with an existing GEISA list, we retrieve propane abundances from two bands at 748 and 1376 cm-1. At 748 cm-1 we retrieve 4.2 +/- 0.5 x 10(-7) (1-sigma error) at 2 mbar, in good agreement with previous studies, although lack of hotbands in the present spectral atlas remains a problem. We also determine 5.7 +/- 0.8 x 10(-7) at 2 mbar from the 1376 cm-1 band - a value that is probably affected by systematic errors including continuum gradients due to haze and also an imperfect model of the n6 band of ethane. This study clearly shows for the first time the ubiquity of propane's emission bands across the thermal infrared spectrum of Titan, and points to an urgent need for further laboratory spectroscopy work, both to provide the line positions and intensities needed to model these bands, and also to further characterize haze spectral opacity. The present lack of accurate modeling capability for propane is an impediment not only for the measurement of propane itself, but also for the search for the emissions of new molecules in many spectral regions.
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。
