Ethyl alcohol and sugar in comet C/2014 Q2 (Lovejoy)
Abstract
The presence of numerous complex organic molecules (COMs; defined as those containing six or more atoms) around protostars shows that star formation is accompanied by an increase of molecular complexity. These COMs may be part of the material from which planetesimals and, ultimately, planets formed. Comets represent some of the oldest and most primitive material in the solar system, including ices, and are thus our best window into the volatile composition of the solar protoplanetary disk. Molecules identified to be present in cometary ices include water, simple hydrocarbons, oxygen, sulfur, and nitrogen-bearing species, as well as a few COMs, such as ethylene glycol and glycine. We report the detection of 21 molecules in comet C/2014 Q2 (Lovejoy), including the first identification of ethyl alcohol (ethanol, C_2H_5OH) and the simplest monosaccharide sugar glycolaldehyde (CH_2OHCHO) in a comet. The abundances of ethanol and glycolaldehyde, respectively 5 and 0.8% relative to methanol (0.12 and 0.02% relative to water), are somewhat higher than the values measured in solar-type protostars. Overall, the high abundance of COMs in cometary ices supports the formation through grain-surface reactions in the solar system protoplanetary disk.
Additional Information
© 2015 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). Submitted 29 June 2015; Accepted 7 August 2015; Published 23 October 2015. The observations were conducted under the target of opportunity proposal D04-14 and regular proposal 128-14. We acknowledge the support from the IRAM director for awarding us discretionary time, and the IRAM staff for its support and for scheduling the observations on short notice. Funding: IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). S.N.M. is supported for this work through the NASA Planetary Astronomy Program. Author contributions: N.B. coordinated the observation program. N.B. and R.M. conducted the IRAM observations. J.C. and A.S. were responsible for the Nançay and Odin comet observations, respectively. P.C. reduced the Nançay OH observations. N.B. carried out the data reduction and modeling of the IRAM and Odin data. D.B.-M. provided the comparative study on complex organics in comet and protostars and other galactic sources of interest. All authors contributed to the observation planning and commented on the manuscript. Competing interests: The authors declare that they have no competing interests. Data and materials availability: The spectral data set is available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5).Attached Files
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Additional details
- PMCID
- PMC4646833
- Eprint ID
- 63122
- Resolver ID
- CaltechAUTHORS:20151222-083209687
- Institut national des sciences de l'Univers (INSU)
- Max-Planck-Gesellschaft
- Instituto Geográfico Nacional (IGN)
- NASA
- Centre National de la Recherche Scientifique (CNRS)
- Created
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2015-12-22Created from EPrint's datestamp field
- Updated
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2022-05-17Created from EPrint's last_modified field