Disentangling Multiple Emitting Components in Molecular Observations with Nonnegative Matrix Factorization
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 do not necessarily arise from a single component. Disentangling multiple gas com...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad1681 |
| _version_ | 1797338607911960576 |
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| author | Damien de Mijolla Jonathan Holdship Serena Viti Johannes Heyl |
| author_facet | Damien de Mijolla Jonathan Holdship Serena Viti Johannes Heyl |
| author_sort | Damien de Mijolla |
| collection | DOAJ |
| description | 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 do not necessarily arise 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 nonnegative matrix factorization (NMF) approach as a means to recover gas components from a set of blended line intensity maps of molecular transitions that may trace different physical conditions. We run a series of experiments on synthetic data sets 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 initialization and regularisation are key factors in the efficiency of the NMF algorithm. |
| first_indexed | 2024-03-08T09:33:45Z |
| format | Article |
| id | doaj.art-4588eb8f7bd54e00a9efa56c8bb2622a |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T09:33:45Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-4588eb8f7bd54e00a9efa56c8bb2622a2024-01-30T15:10:38ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01961222510.3847/1538-4357/ad1681Disentangling Multiple Emitting Components in Molecular Observations with Nonnegative Matrix FactorizationDamien de Mijolla0https://orcid.org/0000-0001-8757-4936Jonathan Holdship1https://orcid.org/0000-0003-4025-1552Serena Viti2https://orcid.org/0000-0001-8504-8844Johannes Heyl3https://orcid.org/0000-0003-0567-8796Department of Physics and Astronomy, University College London , Gower Street, London WC1E 6BT, UK ; viti@strw.leidenuniv.nlDepartment of Physics and Astronomy, University College London , Gower Street, London WC1E 6BT, UK ; viti@strw.leidenuniv.nl; Leiden Observatory, Leiden University , PO Box 9513, NL-2300 RA Leiden, The NetherlandsDepartment of Physics and Astronomy, University College London , Gower Street, London WC1E 6BT, UK ; viti@strw.leidenuniv.nl; Leiden Observatory, Leiden University , PO Box 9513, NL-2300 RA Leiden, The NetherlandsDepartment of Physics and Astronomy, University College London , Gower Street, London WC1E 6BT, UK ; viti@strw.leidenuniv.nlMolecular 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 do not necessarily arise 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 nonnegative matrix factorization (NMF) approach as a means to recover gas components from a set of blended line intensity maps of molecular transitions that may trace different physical conditions. We run a series of experiments on synthetic data sets 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 initialization and regularisation are key factors in the efficiency of the NMF algorithm.https://doi.org/10.3847/1538-4357/ad1681AstrochemistryAstrostatistics techniques |
| spellingShingle | Damien de Mijolla Jonathan Holdship Serena Viti Johannes Heyl Disentangling Multiple Emitting Components in Molecular Observations with Nonnegative Matrix Factorization The Astrophysical Journal Astrochemistry Astrostatistics techniques |
| title | Disentangling Multiple Emitting Components in Molecular Observations with Nonnegative Matrix Factorization |
| title_full | Disentangling Multiple Emitting Components in Molecular Observations with Nonnegative Matrix Factorization |
| title_fullStr | Disentangling Multiple Emitting Components in Molecular Observations with Nonnegative Matrix Factorization |
| title_full_unstemmed | Disentangling Multiple Emitting Components in Molecular Observations with Nonnegative Matrix Factorization |
| title_short | Disentangling Multiple Emitting Components in Molecular Observations with Nonnegative Matrix Factorization |
| title_sort | disentangling multiple emitting components in molecular observations with nonnegative matrix factorization |
| topic | Astrochemistry Astrostatistics techniques |
| url | https://doi.org/10.3847/1538-4357/ad1681 |
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