Formation of molecular oxygen and ozone on amorphous silicates

Dapeng Jing, Jiao He, John Robert Brucato, Gianfranco Vidali, Lorenzo Tozzetti, Antonio De Sio

Research output: Contribution to journalArticle

21 Scopus citations

Abstract

Oxygen in the interstellar medium is seen in the gas phase, in ices (incorporated in H2O, CO, and CO2), and in grains such as (Mg x Fe1- x )SiO3 or (Mg x Fe1- x )2SiO4, 0 < x < 1. In this investigation, we study the diffusion of oxygen atoms and the formation of oxygen molecules and ozone on the surface of an amorphous silicate film. We find that ozone is formed at low temperature (<30K), and molecular oxygen forms when the diffusion of oxygen atoms becomes significant, at around 60K. This experiment, besides being the first determination of the diffusion energy barrier (1785 ± 35 K) for oxygen atoms on a silicate surface, suggests bare silicates as a possible storage place for oxygen atoms in low-Av environments.

Original languageEnglish (US)
Article number98
JournalAstrophysical Journal
Volume756
Issue number1
DOIs
StatePublished - Sep 1 2012

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Keywords

  • astrochemistry
  • dust, extinction
  • ISM: molecules
  • methods: laboratory
  • molecular processes

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

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