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


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 A59

Turbulensdiagnostik 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



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