2023/12/19 by Damien de Mijolla, Jonathan Holdship, de Mijolla, Damien +5 · 1 citation
Chemistry · Earth and Planetary Sciences · Medicine · #Astrophysics of Galaxies (astro-ph.GA) #Atmospheric Ozone and Climate #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Optical Imaging and Spectroscopy Techniques #Spectroscopy and Laser Applications
paper · pdf · doi:10.48550/arxiv.2312.12646
openalex publication_date 2023/12/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Molecular emission from the galactic and extragalactic interstellar medium (ISM) is often used to determine the physical conditions of the dense gas. However, even from spatially resolved regions, the observed molecules are not necessarily arising from a single component. Disentangling multiple gas components is often a degenerate problem in radiative transfer studies. In this paper we investigate the use of the non-negative matrix factorization (NMF) approach as a means to recover gas components from a set of blended line intensity maps of molecular transitions which may trace different physical conditions. We run a series of experiments on synthetic datasets designed to replicate conditions in two very different environments: galactic pre-stellar cores and the ISM in high redshift galaxies. We find that the NMF algorithm often recovers the multiple components resembling those used in the data-generating process, provided that the different components have similar column densities. When NMF fails to recover all the individual components it does however group together the most similarly emitting ones. We further found that initialisation and regularisation are key factors in the efficiency of the NMF algorithm.