| Autor: |
Bézard, B., Nixon, C. A., Vinatier, S., Lellouch, E., Greathouse, T., Giles, R., Lombardo, N. A., Jolly, A. |
| Rok vydání: |
2024 |
| Předmět: |
|
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1016/j.icarus.2024.116221 |
| Popis: |
We report observations of deuterated acetylene (C$_2$HD) at 19.3 $\mu$m (519 cm$^{-1}$) with the Texas Echelon Cross Echelle Spectrograph on the NASA Infrared Telescope Facility in July 2017. Six individual lines from the Q-branch of the $\nu_4$ band were clearly detected with a S/N ratio up to 10. Spectral intervals around 8.0 $\mu$m (745 cm$^{-1}$) and 13.4 $\mu$m (1247 cm$^{-1}$) containing acetylene (C$_2$H$_2$) and methane (CH$_4$) lines respectively, were observed during the same run to constrain the disk-averaged C$_2$H$_2$ abundance profile and temperature profile. Cassini observations with the Composite Infrared Spectrometer (CIRS) were used to improve the flux calibration and help to constrain the atmospheric model. The measured D/H ratio in acetylene, derived from the C$_2$HD/C$_2$H$_2$ abundance ratio, is (1.22$^{+0.27}_{-0.21})$ $\times$ 10$^{-4}$, consistent with that in methane obtained in previous studies. Possible sources of fractionation at different steps of the acetylene photochemistry are investigated. |
| Databáze: |
arXiv |
| Externí odkaz: |
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