Comparing ice composition in dark molecular clouds

Abstract

We present 520 m Spitzer/IRS spectroscopy toward stars behind dark molecular clouds. We present preliminary results from the Serpens dark cloud to show the variation between environments within a cloud. We are surveying 3 clouds with varying levels of star formation activity. Serpens has the highest level of activity from our 3 clouds. We show that location as well extinction can cause variations in ice composition. We also find that some lines of sight contain organic molecules such as methane and methanol, and the first detection of acetylene ice in the interstellar medium. We believe the high extinction lines of sight have been enriched by star formation activity near those lines of sight. © 2008 International Astronomical Union.