A dynamically young, gravitationally stable network of filaments in Orion B
PETY, Jerome
Institut de RadioAstronomie Millimétrique [IRAM]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
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Institut de RadioAstronomie Millimétrique [IRAM]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
PETY, Jerome
Institut de RadioAstronomie Millimétrique [IRAM]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
Institut de RadioAstronomie Millimétrique [IRAM]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
GERIN, Maryvonne
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
LEVRIER, François
Laboratoire de Radioastronomie [LRA]
Astrophysique
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
Laboratoire de Radioastronomie [LRA]
Astrophysique
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
BRON, Emeric
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
GOICOECHEA, Javier
Consejo Superior de Investigaciones Cientificas [España] = Spanish National Research Council [Spain] [CSIC]
Consejo Superior de Investigaciones Cientificas [España] = Spanish National Research Council [Spain] [CSIC]
HUGHES, Annie
Max-Planck-Institut für Astronomie [MPIA]
Institut de recherche en astrophysique et planétologie [IRAP]
Max-Planck-Institut für Astronomie [MPIA]
Institut de recherche en astrophysique et planétologie [IRAP]
LANGUIGNON, David
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
LE PETIT, Franck
MIS
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
MIS
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
ROUEFF, Evelyne
Laboratoire Univers et Théories [LUTH (UMR_8102)]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
< Réduire
Laboratoire Univers et Théories [LUTH (UMR_8102)]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
Langue
en
Article de revue
Ce document a été publié dans
Astronomy and Astrophysics - A&A. 2019, vol. 624, p. A113
EDP Sciences
Résumé en anglais
Context. Filaments are a key step on the path that leads from molecular clouds to star formation. However, their characteristics, for instance their width, are heavily debated and the exact processes that lead to their ...Lire la suite >
Context. Filaments are a key step on the path that leads from molecular clouds to star formation. However, their characteristics, for instance their width, are heavily debated and the exact processes that lead to their formation and fragmentation into dense cores still remain to be fully understood.Aims. We aim at characterising the mass, kinematics, and stability against gravitational collapse of a statistically significant sample of filaments in the Orion B molecular cloud, which is renown for its very low star formation efficiency.Methods. We characterised the gas column densities and kinematics over a field of 1.9 deg2, using C18O (J = 1−0) data from the IRAM 30 m large programme ORION-B at angular and spectral resolutions of 23.5″ and 49.5 kHz, respectively. Using two different Hessian-based filters, we extracted and compared two filamentary networks, each containing over 100 filaments.Results. Independent of the extraction method, the filament networks have consistent characteristics. The filaments have widths of ~0.12 ± 0.04 pc and show a wide range of linear (~1−100 M⊙ pc−1) and volume densities (~2 × 103−2 × 105 cm−3). Compared to previous studies, the filament population is dominated by low-density, thermally sub-critical structures, suggesting that most of the identified filaments are not collapsing to form stars. In fact, only ~1% of the Orion B cloud mass covered by our observations can be found in super-critical, star-forming filaments, explaining the low star formation efficiency of the region. The velocity profiles observed across the filaments show quiescence in the centre and coherency in the plane of the sky, even though these profiles are mostly supersonic.Conclusions. The filaments in Orion B apparently belong to a continuum which contains a few elements comparable to already studied star-forming filaments, for example in the IC 5146, Aquila or Taurus regions, as well as many lower density, gravitationally unbound structures. This comprehensive study of the Orion B filaments shows that the mass fraction in super-critical filaments is a key factor in determining star formation efficiency.< Réduire
Mots clés en anglais
Astrophysics - Astrophysics of Galaxies
ISM: clouds
ISM: structure
ISM: kinematics and dynamics
methods: data analysis
radio lines: ISM
ISM: individual objects: Orion B
Origine
Importé de halUnités de recherche