The CARMA-NRO Orion Survey: Filament Formation via Collision-induced Magnetic Reconnection—the Stick in Orion A
Abstract
A unique filament is identified in the Herschel maps of the Orion A giant molecular cloud. The filament, which we name the Stick, is ruler-straight and at an early evolutionary stage. Transverse position-velocity diagrams show two velocity components closing in on the Stick. The filament shows consecutive rings/forks in C18O (1-0) channel maps, which is reminiscent of structures generated by magnetic reconnection. We propose that the Stick formed via collision-induced magnetic reconnection (CMR). We use the magnetohydrodynamics code Athena++ to simulate the collision between two diffuse molecular clumps, each carrying an antiparallel magnetic field. The clump collision produces a narrow, straight, dense filament with a factor of >200 increase in density. The production of the dense gas is seven times faster than freefall collapse. The dense filament shows ring/fork-like structures in radiative transfer maps. Cores in the filament are confined by surface magnetic pressure. CMR can be an important dense-gas-producing mechanism in the Galaxy and beyond.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2021
- DOI:
- arXiv:
- arXiv:2011.00183
- Bibcode:
- 2021ApJ...906...80K
- Keywords:
-
- Molecular clouds;
- Magnetic fields;
- Star formation;
- Interstellar filaments;
- Interstellar medium;
- Giant molecular clouds;
- Millimeter astronomy;
- Computational astronomy;
- Astrophysical fluid dynamics;
- Magnetohydrodynamical simulations;
- Observational astronomy;
- Theoretical models;
- 1072;
- 994;
- 1569;
- 842;
- 847;
- 653;
- 1061;
- 293;
- 101;
- 1966;
- 1145;
- 2107;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 39 pages, 31 figures, 2 tables, accepted by ApJ