First Comet Observations with NIRSPEC-2 at Keck: Outgassing Sources of Parent Volatiles and Abundances Based on Alternative Taxonomic Compositional Baselines in 46P/Wirtanen
| Autor: | Nicolas Biver, Mohammad Saki, Michael A. DiSanti, Emily C. Martin, Kumar Venkataramani, Gregory Doppmann, Michael R. Combi, Geronimo L. Villanueva, Hideyo Kawakita, Boncho P. Bonev, Erika L. Gibb, Nathan Roth, Younas Khan, Martin A. Cordiner, Ronald J. Vervack, Jacques Crovisier, Adam J. McKay, Dennis Bodewits, Anita L. Cochran, Yinsi Shou, Neil Dello Russo |
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| Přispěvatelé: | American University Washington D.C. (AU), Johns Hopkins University (JHU), GSFC Planetary Systems Laboratory, NASA Goddard Space Flight Center (GSFC), University of California [Santa Cruz] (UCSC), University of California, W.M. Keck Observatory, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Kyoto Sangyo University, University of Missouri [St. Louis], University of Missouri System, University of Michigan [Ann Arbor], University of Michigan System, Universities Space Research Association (USRA), Catholic University of America, Auburn University (AU), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), McDonald Observatory, University of Texas at Austin [Austin] |
| Rok vydání: | 2021 |
| Předmět: |
[PHYS]Physics [physics]
Physics Solar System 010504 meteorology & atmospheric sciences Comet Astronomy and Astrophysics 01 natural sciences Astrobiology Outgassing Geophysics 13. Climate action Space and Planetary Science 0103 physical sciences Earth and Planetary Sciences (miscellaneous) 010303 astronomy & astrophysics 0105 earth and related environmental sciences |
| Zdroj: | The Planetary Science Journal The Planetary Science Journal, IOP Science, 2021, 2 (2), pp.45. ⟨10.3847/psj/abd03c⟩ |
| ISSN: | 2632-3338 |
| Popis: | A major upgrade to the NIRSPEC instrument at the Keck II telescope was successfully completed in time for near-infrared spectroscopic observations of comet 46P/Wirtanen during its exceptionally close flyby of Earth in 2018 December. These studies determined the abundances of several volatiles, including C2H2, C2H6, CH3OH, NH3, HCN, H2CO, and H2O. Long-slit spatial distributions of gas rotational temperature and column density are diagnostic for the presence of icy grains in the coma and understanding if different volatiles are associated with common or distinct outgassing sources. These spatial distributions suggest that C2H2, C2H6, and HCN have a common outgassing source, whereas H2O and CH3OH have additional, more extended sources. The synergy of these findings with observations by space missions (Rosetta and EPOXI) motivates continuing studies to address whether or not C2H6, C2H2, and HCN have a common source of release (plausibly associated with CO2) in a larger sample of comets and whether systematic differences exist in the release of these species compared to H2O and CH3OH. Abundances of volatiles are reported relative to H2O, as traditionally done, as well as C2H6. While not unique, the choice of C2H6 demonstrates the value of extending the chemical taxonomy of parent volatiles in comets toward additional compositional “baselines” and, importantly, closer integration between coma abundances and the underlying volatile associations as revealed by spatial distributions. Our findings on composition and sources of outgassing include information relevant to future evaluations of 46P/Wirtanen as a prospective spacecraft target. |
| Databáze: | OpenAIRE |
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