Radical-induced chemistry from VUV photolysis of interstellar ice analogues containing formaldehyde - Archive ouverte HAL Access content directly
Journal Articles Astronomy and Astrophysics - A&A Year : 2016

Radical-induced chemistry from VUV photolysis of interstellar ice analogues containing formaldehyde

(1) , (1) , (1) , (1)
1

Abstract

Surface processes and radical chemistry within interstellar ices are increasingly suspected to play an important role in the formation of complex organic molecules (COMs) observed in several astrophysical regions and cometary environments. We present new laboratory experiments on the low-temperature solid state formation of complex organic molecules – glycolaldehyde, ethylene glycol, and polyoxymethylene – through radical-induced reactivity from VUV photolysis of formaldehyde in water-free and water-dominated ices. Radical reactivity and endogenous formation of COMs were monitored in situ via infrared spectroscopy in the solid state and post photolysis with temperature programmed desorption (TPD) using a quadripole mass spectrometer. We show the ability of free radicals to be stored when formed at low temperature in water-dominated ices, and to react with other radicals or on double bonds of unsaturated molecules when the temperature increases. It experimentally confirms the role of thermal diffusion in radical reactivity. We propose a new pathway for formaldehyde polymerisation induced by HCO radicals that might explain some observations made by the Ptolemy instrument on board the Rosetta lander Philae. In addition, our results seem to indicate that H-atom additions on H 2 CO proceed preferentially through CH 2 OH intermediate radicals rather than the CH 3 O radical.
Fichier principal
Vignette du fichier
aa28258-16.pdf (1.95 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Loading...

Dates and versions

hal-01451877 , version 1 (01-02-2017)

Identifiers

Cite

Teddy Butscher, Fabrice Duvernay, Grégoire Danger, Thierry Chiavassa. Radical-induced chemistry from VUV photolysis of interstellar ice analogues containing formaldehyde. Astronomy and Astrophysics - A&A, 2016, 593, pp.A60. ⟨10.1051/0004-6361/201628258⟩. ⟨hal-01451877⟩

Collections

CNRS UNIV-AMU PIIM
91 View
217 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More