New experimental sublimation energy measurements for some relevant astrophysical ices

Centro de Tecnologías Físicas. Universitat Politècnica de València, Plaza Ferrándiz Carbonell, 03801 Alcoy, Spain
e-mail: ralunam@fis.upv.es

Received: 13 December 2013
Accepted: 5 April 2014

Abstract

Context. The knowledge of the sublimation energy of ices allows us to better understand the dynamics between surfaces and atmospheres of different environments of astrophysical interest where ices are present.

Aims. This work is intended to provide sublimation energy values for a set of pure ices (CO, CH₄, CO₂, N₂, and NH₃) using a new experimental procedure. The results were compared to some values obtained by other authors under different conditions and/or methods, to check the reliability of this new method.

Methods. We used the frequency variation obtained from a quartz crystal microbalance to calculate the sublimation energy from the Polany-Wigner equation for the first time.

Results. The results obtained are relevant since there are few previous values of sublimation energy reported on these molecules in these conditions of pressure and temperature, which are representative of astrophysical regions. These values are needed in models used to interpret dynamics of icy surfaces. In general, our results compare well to other ones obtained by different methods and complement those previously available.