Low-temperature surface formation of NH_3 and HNCO: hydrogenation of nitrogen atoms in CO-rich interstellar ice analogues
Abstract
Solid-state astrochemical reaction pathways have the potential to link the formation of small nitrogen-bearing species, like NH_3 and HNCO, and prebiotic molecules, specifically amino acids. To date, the chemical origin of such small nitrogen-containing species is still not well understood, despite the fact that ammonia is an abundant constituent of interstellar ices towards young stellar objects and quiescent molecular clouds. This is mainly because of the lack of dedicated laboratory studies. The aim of this work is to experimentally investigate the formation routes of NH_3 and HNCO through non-energetic surface reactions in interstellar ice analogues under fully controlled laboratory conditions and at astrochemically relevant temperatures. This study focuses on the formation of NH_3 and HNCO in CO-rich (non-polar) interstellar ices that simulate the CO freeze-out stage in dark interstellar cloud regions, well before thermal and energetic processing start to become relevant. We demonstrate and discuss the surface formation of solid HNCO through the interaction of CO molecules with NH radicals – one of the intermediates in the formation of solid NH_3 upon sequential hydrogenation of N atoms. The importance of HNCO for astrobiology is discussed.
Additional Information
© 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2014 September 26; received 2014 September 25; in original form 2014 July 02. First published online November 12, 2014. We thank Dr Herma Cuppen for useful discussions. This work is financially supported by the European Community's Seventh Framework Programme (FP7/2007–2013) under grant agreement no. 238258 (LASSIE), the Netherlands Organization for Scientific Research (NWO) through aVICI grant, andNOVA, the Netherlands Research School for Astronomy. Support for SI from the Niels Stensen Fellowship and theMarie Curie Fellowship (FP7-PEOPLE-2011-IOF-300957) is gratefully acknowledged.Attached Files
Published - MNRAS-2015-Fedoseev-439-48.pdf
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Additional details
- Eprint ID
- 55639
- Resolver ID
- CaltechAUTHORS:20150309-110738995
- 238258 (LASSIE)
- European Research Council (ERC)
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
- Nederlandse Onderzoekschool Voor Astronomie (NOVA)
- Niels Stensen Fellowship
- FP7-PEOPLE- 2011-IOF-300957
- Marie Curie Fellowship
- Created
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2015-03-09Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field