The temperature dependence of the CO infrared band strength in CO:H2O ices

Abstract

Experimental results on the temperature dependence of the C-triple-bond-O stretch band of CO in H20 ices are presented, and the astrophysical significance of the results is discussed. When CO is trapped in water-rich ice mixtures, the 2137/cm and 2152/cm absorptions are found to undergo irreversible changes in shape upon warmup. The present results suggest that, for interstellar grains, the amount of solid CO embedded in water-rich ice mantles may be underestimated by as much as 40 percent.