Atomic and molecular gas in the Milky Way. I. Structure decomposition

Fuente: arXiv
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Auteurs principaux: Liu, Xin, Du, Fujun
Format: Preprint
Publié: 2025
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author Liu, Xin
Du, Fujun
author_facet Liu, Xin
Du, Fujun
contents We present GDCluster, a fully automated algorithm for decomposing spectral-line datacube of interstellar gas into coherent structures. Assuming a multi-Gaussian nature of observed spectra, GDCluster employs and augments the derivative spectroscopy technique for precise parameter estimation, incorporates spatial-continuity constraints during spectral fitting, and extends these constraints to spatial clustering. This approach effectively resolves velocity blending structures in PPV space-particularly critical for ubiquitous HI spectra where emissions from multiple phases are severely blended. Applied to the all-sky HI4PI data, a 10 degree times 10 degree CRAFTS survey region, and a 45 degree times 10 degree MWISP survey region, GDCluster extracts 45,299, 2247, and 47,119 structures in HI and CO (1-0), respectively. Comparative analyses demonstrate GDCluster's superiority over DBSCAN in separating overlapping spectra with complex velocity components.
format Preprint
id arxiv_https___arxiv_org_abs_2509_16572
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Atomic and molecular gas in the Milky Way. I. Structure decomposition
Liu, Xin
Du, Fujun
Astrophysics of Galaxies
We present GDCluster, a fully automated algorithm for decomposing spectral-line datacube of interstellar gas into coherent structures. Assuming a multi-Gaussian nature of observed spectra, GDCluster employs and augments the derivative spectroscopy technique for precise parameter estimation, incorporates spatial-continuity constraints during spectral fitting, and extends these constraints to spatial clustering. This approach effectively resolves velocity blending structures in PPV space-particularly critical for ubiquitous HI spectra where emissions from multiple phases are severely blended. Applied to the all-sky HI4PI data, a 10 degree times 10 degree CRAFTS survey region, and a 45 degree times 10 degree MWISP survey region, GDCluster extracts 45,299, 2247, and 47,119 structures in HI and CO (1-0), respectively. Comparative analyses demonstrate GDCluster's superiority over DBSCAN in separating overlapping spectra with complex velocity components.
title Atomic and molecular gas in the Milky Way. I. Structure decomposition
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2509.16572