Structure and Composition of the Interstellar and Circumstellar Medium
Mapping of Ice on 1000 AU scales with AKARI
Date Submitted
2015-04-01 19:04:57
Aleksi Suutarinen
Helen J. Fraser (The Open University)
The Open University
Reactions on the surfaces of dust grains play a vital role in the overall chemistry of interstellar matter. These grains become covered by icy layers, which are the largest molecular reservoir in the interstellar medium. Given this, it is surprising that the effect ice has on the overall chain of reactions is poorly characterized. One step on the path of gaining better understanding here is to develop methods of figuring out how much ice is present in these clouds, the links between ice components, and synergy between the ices and gas phase molecules. We do this by examining the absorption spectra of ices on lines of sight towards several stars behind clouds of interstellar matter. From these we can reconstruct spatial maps of the ice distribution, as a test of the chemical variation within a cloud.
In this talk we present the continuing results of our ice mapping programme, using data from the AKARI satellite, specifically in slitless spectroscopy observations in the NIR. In this region the key ice features encompass H$_2$O, CO and CO$_2$. The maps illustrate the power of our dedicated AKARI data reduction pipeline, and the novelty of our observing programme. We also detail the next steps' in our ice mapping research. The method is being expanded to include the full 10' $\time$ 10' AKARI field of view, taking account of image distortion induced by the dispersing optics. This talk focuses especially on the star-forming region around Barnard 35A, although other regions are also discussed.