The efficient photodesorption of nitric oxide (NO) ices

A laboratory astrophysics study

¹ Laboratoire d’Étude du Rayonnement et de la Matière en Astrophysique et Atmosphères (LERMA), Sorbonne Universités, UPMC Univ. Paris 06, Observatoire de Paris, PSL Research University, CNRS, 75005 Paris, France
e-mail: geraldine.feraud@upmc.fr
² Laboratoire de Chimie Physique (LCP), CNRS UMR 8000, Univ. Paris Sud, 91400 Orsay, France
³ CERN, 1211 Geneva 23, Switzerland
⁴ Laboratori Nazionali di Frascati (LNF)-INFN, 00044 Frascati, Italy

Received: 26 July 2017
Accepted: 24 September 2017

Abstract

The study and quantification of UV photon-induced desorption of frozen molecules furthers our understanding of the chemical evolution of cold interstellar regions. Nitric oxide (NO) is an important intermediate species in both gas-phase and solid-phase chemical networks. In this work, we present quantitative measurements of the photodesorption of a pure NO ice. We used the tunable monochromatic synchrotron light of the DESIRS beamline of the SOLEIL facility near Paris to irradiate NO ices in the 6–13.6 eV range and measured desorption by quadrupole mass spectrometry. We find that NO photodesorption is very efficient, its yield being around 10^-2 molecule per incident photon for UV fields relevant to the diffuse and dense interstellar medium. We discuss the extrapolation of our results to an astrophysical context and we compare photodesorption of NO to previously studied molecules.