A 3D view of the outflow in the Orion Molecular Cloud 1 (OMC-1)

Abstract

The fast outflow emerging from a region associated with massive star formation in the Orion Molecular Cloud 1 (OMC-1), located behind the Orion Nebula, appears to have been set in motion by an explosive event. Here we study the structure and dynamics of outflows in OMC-1. We combine radial velocity and proper motion data for near-IR emission of molecular hydrogen to obtain the first 3-dimensional (3D) structure of the OMC-1 outflow. Our work illustrates a new diagnostic tool for studies of star formation that will be exploited in the near future with the advent of high spatial resolution spectro-imaging in particular with data from the Atacama Large Millimeter Array (ALMA). We use published radial and proper motion velocities obtained from the shock-excited vibrational emission in the H2 v=1-0 S(1) line at 2.122 $\mu$m obtained with the GriF instrument on the Canada-France-Hawaii Telescope, the Apache Point Observatory, the Anglo-Australian Observatory and the Subaru Telescope. These data give the 3D velocity of ejecta yielding a 3D reconstruction of the outflows. This allows one to view the material from different vantage points in space giving considerable insight into the geometry. Our analysis indicates that the ejection occurred <720 years ago from a distorted ring-like structure of ~15" (6000 AU) in diameter centered on the proposed point of close encounter of the stars BN, source I and maybe also source n. We propose a simple model involving curvature of shock trajectories in magnetic fields through which the origin of the explosion and the centre defined by extrapolated proper motions of BN, I and n may be brought into spatial coincidence.

Accepted for publication in Astronomy and Astrophysics (A&A), 12 pages, 9 figures

References in corpus (5)

• The distance to the Orion Nebula
• Monitoring the Large Proper Motions of Radio Sources in the Orion BN/KL Region
• Identifying the outflow driving sources in Orion-KL
• OH maser disc and outflow in the Orion-BN/KL region
• NICMOS Observations of Shocked H_2 in Orion

Cited by in corpus (10)

• Herschel observations of EXtra-Ordinary Sources: Analysis of the HIFI 1.2 THz Wide Spectral Survey Toward Orion KL I. Methods
• Herschel Far-Infrared Spectral-mapping of Orion BN/KL Outflows: Spatial distribution of excited CO, H2O, OH, O and C+ in shocked gas
• Herschel HIFI observations of O${}_2$ toward Orion: special conditions for shock enhanced emission
• The complexity of Orion: an ALMA view. II. gGg'-Ethylene Glycol and Acetic Acid
• The mid-infrared molecular inventory towards Orion IRc2
• The complexity of Orion: an ALMA view III. The explosion impact
• Mid-J CO emission from the Orion BN/KL explosive outflow
• An orbital release model for the Orion BN/KL fingers
• Formation of Orion Fingers
• Dense Molecular Ring-like structure in gaseous CO depletion region G34.74-0.12