Volume 545, September 2012
|Number of page(s)||5|
|Published online||11 September 2012|
Thermal collapse of porous interstellar ice
Raymond and Beverly Sackler Laboratory for Astrophysics, Leiden
Observatory, Leiden University,
PO Box 9513,
e-mail: firstname.lastname@example.org; email@example.com
Received: 4 April 2012
Accepted: 27 July 2012
Aims. This article aims at a quantitative characterization of the phase transition of porous amorphous solid water (ASW) to a non-porous, i.e., more compact structure over an astronomically relevant temperature regime.
Methods. A new laboratory based method is described that monitors the ice thickness decrease by combining optical interference with Fourier transform infrared spectroscopy. Three different water ice morphologies are studied; porous ASW as primary target, and less-porous ASW as well as crystalline solid water for comparison.
Results. The thickness of the porous ASW sample is found to decrease by 12 ± 1% upon heating from 20 to 120 K. The thickness decrease of less-porous ASW is smaller, and negligible for crystalline solid water.
Conclusions. Porous ASW, if formed under interstellar conditions, is expected to become less porous with increasing temperature. The thermally induced structural collapse affects the diffusion of the interstellar ice components, and therefore the catalytic properties of the ice.
Key words: astrochemistry / methods: laboratory / ISM: molecules
© ESO, 2012
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.