A Comparison of Non Negative Blind Source Separation Methods for Identifying Astrophysical Ice Compounds

The analysis of astrophysical ices and the determination of the compounds that are present in the molecular clouds play a fundamental role in order to predict the future evolution of the cloud, e.g., its transformation to protostellar bodies or the appearance of new radicals and molecules. Because of the difficulties of obtaining satellite data, the process is simulated first in the laboratory generating ice analogs under controlled conditions. In this case, the ice mixture is carried on allocating the different components in the appropriate concentrations in a deposit chamber with a substrate and recording the spectrum of the aggregated ice when the chamber is filled through a gas inlet with the corresponding compounds (see Figure 1). This process tries to simulate the real process of forming ice mantles under the environmental conditions of the Interstellar Medium. The spectrum is obtained analyzing the transfer function of the ice when it is excited by a source beam with a known spectrum and measuring with a detector the output spectrum after crossing the ice.