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A multiwavelength study of outflows in OMC-2/3

Yu, K.C., Billawala, Y., Smith, M.D., Bally, J., Butner, H.M. (2000) A multiwavelength study of outflows in OMC-2/3. Astronomical Journal, 120 (4). pp. 1974-2006. ISSN 0004-6256. (doi:10.1086/301565) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:50138)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided.
Official URL
http://dx.doi.org/10.1086/301565

Abstract

We present new ? = 1-0 S(1) H 2, 12CO J = 2 ? 1, and 12CO J = 3 ? 2 observations of the star-forming clouds OMC-2 and OMC-3, one of the densest known groupings of outflows from low-mass young stellar objects (YSOs) in the sky. High-velocity 12CO J = 2 ? 1 gas in this region suggests that previously discovered H 2 flows are driving and entraining molecular outflows. However, the large number of sources and flows within the narrow molecular filament means it is difficult to make a firm association of molecular outflow gas with H 2 flows, except for in the case of the bipolar east-west H flow. A number of Herbig-Haro (HH) objects, including ones far to the west and east of the main ridge, are identified with H 2 knots. High-resolution spectroscopy in the ? = 1-0 S(1) line of 10 H 2 knots shows line profiles consistent with dual forward and reverse shocks. C-shock modeling suggest that asymmetries seen in suspected bow shocks could be evidence of varying magnetic field orientations throughout the cloud. One of the bow shocks in the H flow, YBD-5, can be successfully modeled by a 100 km s -1 C-shock propagating into a magnetized, 10 6 cm -3 medium, although the observations and limitations within the computer code itself do not entirely rule out J-shocks. Mass spectra of the H flow are broken power laws, which might be evidence for a jet that has two entrainment mechanisms for accelerating ambient molecular gas into the outflow. The H 2 luminosity in this flow is many times smaller than the CO mechanical luminosity, but this fact cannot rule out the possibility that a narrow highly collimated jet drives the molecular outflow, owing to uncertainties in extinction, outflow dynamic times, cooling contributions from other lines, and the wind model used. Outflows from OMC-2/3 are likely to contribute to the turbulent pumping of gas within the molecular ridge north of the Orion Nebula. High-velocity gas clumps north of the sources investigated here may represent evidence of additional undiscovered outflows from young stars.

Item Type: Article
DOI/Identification number: 10.1086/301565
Uncontrolled keywords: ISM: Herbig-Haro objects, ISM: individual (OMC-2, OMC-3), ISM: jets and outflows, Stars: formation, Techniques: spectroscopic
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: Giles Tarver
Date Deposited: 11 Aug 2015 10:18 UTC
Last Modified: 16 Nov 2021 10:20 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/50138 (The current URI for this page, for reference purposes)
Smith, M.D.: https://orcid.org/0000-0002-4289-5952
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