2011/04/25 by N. Billot, E. Schisano, M. Pestalozzi +11 · 20 citations
Chemistry · Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Far infrared #Galactic plane #Galaxy #Infrared #Mass distribution #Molecular Spectroscopy and Structure #Molecular cloud #Physics #Protostar #Remote sensing #Spatial distribution #Star cluster #Star formation #Stars #Stellar, planetary, and galactic studies #Submillimeter Array #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/735/1/28
published in The Astrophysical Journal 735(1), 28 (IOP Publishing) · 17 pages, 9 figures, accepted for publication in ApJ
arxiv created 2011/04/25 · openalex publication_date 2011/06/10 · arxiv updated 2015/05/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We use a minimum spanning tree (MST) algorithm to characterize the spatial distribution of Galactic far-IR sources and derive their clustering properties. We aim to reveal the spatial imprint of different types of star-forming processes, e.g., isolated spontaneous fragmentation of dense molecular clouds, or events of triggered star formation around H ii regions, and highlight global properties of star formation in the Galaxy. We plan to exploit the entire Herschel infrared GALactic (Hi-GAL) survey of the inner Galactic plane to gather significant statistics on the clustering properties of star-forming regions and to look for possible correlations with source properties such as mass, temperature, or evolutionary stage. In this paper, we present a pilot study based on the two 2° × 2° fields centered at longitudes l = 30° and l = 59° obtained during the science demonstration phase of the Herschel mission. We find that over half of the clustered sources are associated with H ii regions and infrared dark clouds. Our analysis also reveals a smooth chromatic evolution of the spatial distribution where sources detected at short wavelengths, likely protostars surrounded by warm circumstellar material emitting in the far-infrared, tend to be clustered in dense and compact groups around H ii regions while sources detected at long wavelengths, presumably cold and dusty density enhancements of the ISM emitting in the submillimeter, are distributed in larger and looser groups.