Gas kinematics around filamentary structures in the Orion B cloud
Journal article, 2023
Context. Understanding the initial properties of star-forming material and how they affect the star formation process is key. From an observational point of view, the feedback from young high-mass stars on future star formation properties is still poorly constrained. Aims. In the framework of the IRAM 30m ORION-B large program, we obtained observations of the translucent (2 ≤ AV < 6 mag) and moderately dense gas (6 ≤ AV < 15 mag), which we used to analyze the kinematics over a field of 5 deg2 around the filamentary structures. Methods. We used the Regularized Optimization for Hyper-Spectral Analysis (ROHSA) algorithm to decompose and de-noise the C 18 O(1−0) and 13CO(1−0) signals by taking the spatial coherence of the emission into account. We produced gas column density and mean velocity maps to estimate the relative orientation of their spatial gradients. Results. We identified three cloud velocity layers at different systemic velocities and extracted the filaments in each velocity layer. The filaments are preferentially located in regions of low centroid velocity gradients. By comparing the relative orientation between the column density and velocity gradients of each layer from the ORION-B observations and synthetic observations from 3D kinematic toy models, we distinguish two types of behavior in the dynamics around filaments: (i) radial flows perpendicular to the filament axis that can be either inflows (increasing the filament mass) or outflows and (ii) longitudinal flows along the filament axis. The former case is seen in the Orion B data, while the latter is not identified. We have also identified asymmetrical flow patterns, usually associated with filaments located at the edge of an H II region. Conclusions. This is the first observational study to highlight feedback from H II regions on filament formation and, thus, on star formation in the Orion B cloud. This simple statistical method can be used for any molecular cloud to obtain coherent information on the kinematics.
ISM: individual objects: Orion B
ISM: kinematics and dynamics
Radio lines: ISM
HII regions
Stars: formation
ISM: clouds
Author
Mathilde Gaudel
Paris Observatory
Jan Orkisz
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
M. Gerin
Paris Observatory
J. Pety
Institut de Radioastronomie Millimétrique (IRAM)
Paris Observatory
Antoine Roueff
Institut Fresnel
Antoine Marchal
Canadian Institute for Theoretical Astrophysics
F. Levrier
Laboratoire de Physique de l’Ecole Normale Supérieure
Marc Antoine Miville-Deschênes
University Paris-Saclay
Javier R. Goicoechea
CSIC - Instituto de Fisica Fundamental (IFF)
Evelyne Roueff
Paris Observatory
Franck Le Petit
Paris Observatory
Victor De Souza Magalhaes
Institut de Radioastronomie Millimétrique (IRAM)
Pierre Palud
Paris Observatory
Miriam G. Santa-Maria
CSIC - Instituto de Fisica Fundamental (IFF)
Maxime Vono
University of Toulouse
Sébastien Bardeau
Institut de Radioastronomie Millimétrique (IRAM)
E. Bron
Paris Observatory
Pierre Chainais
University of Lille
Jocelyn Chanussot
Grenoble Alpes University
P. Gratier
Laboratoire d'Astrophysique de Bordeaux
Viviana Guzman
Pontificia Universidad Catolica de Chile
Annie Hughes
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Jouni Kainulainen
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
David Languignon
Paris Observatory
Jacques Le Bourlot
Paris Descartes University
Paris Observatory
Harvey Liszt
National Radio Astronomy Observatory
K. I. Öberg
Harvard-Smithsonian Center for Astrophysics
Nicolas Peretto
Cardiff University
Albrecht Sievers
Institut de Radioastronomie Millimétrique (IRAM)
P., Tremblin
Maison de la Simulation
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 670 A59Turbulensdiagnostik i molekylmolnen i solens närhet
Swedish Research Council (VR) (2017-03864), 2018-01-01 -- 2020-12-31.
Subject Categories
Meteorology and Atmospheric Sciences
Astronomy, Astrophysics and Cosmology
Fluid Mechanics and Acoustics
DOI
10.1051/0004-6361/202142109