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A near-infrared study of the bow shocks within the L1634 protostellar outflow

O'Connell, B., Smith, M.D., Davis, C.J., Hodapp, K.W., Khanzadyan, T., Ray, T. (2004) A near-infrared study of the bow shocks within the L1634 protostellar outflow. Astronomy and Astrophysics, 419 (3). pp. 975-990. ISSN 0004-6361. (doi:10.1051/0004-6361:20034551) (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)

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. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1051/0004-6361:20034551

Abstract

The L1634 bright-rimmed globule contains an intriguing arrangement of shock structures: two series of aligned molecular shock waves associated with the Herbig-Haro flows HH 240 and HH 241. We present near-infrared spectroscopy and narrow-band imaging in the (1,0) S(1) and (2, 1) S(1) emission lines of molecular hydrogen. These observations yield the spatial distributions of both the molecular excitation and velocity, which demonstrate distinct properties for the individual bow shocks. Bow shock models are applied, varying the shock physics, geometry, speed, density and magnetic field properties to fit two prominent bow shocks. The models predict that both bows move at 60° to the plane of the sky. High magnetic fields and low molecular fractions are implied. The advancing compact bow HH 240C is interpreted as a J-type bow (frozen-in magnetic field) with the flanks in transition to C-type (field diffusion). It is a paraboloidal bow of speed ?42kms-1 entering a medium of quite high density (2 × 104 cm-3), The following bow HH 240A is faster despite a lower excitation, moving through a lower density medium. We find a C-type bow shock model to fit all the data for HH 240A. The favoured bow models are then tested comprehensively against published H 2 emission line fluxes and CO spectroscopy. We conclude that, while the CO emission originates from cloud gas directly set in motion, the H 2 emission is generated from shocks sweeping through an outflow. Also considering optical data, we arrive at a global outflow model involving episodic slow-precessing twin jets.

Item Type: Article
DOI/Identification number: 10.1051/0004-6361:20034551
Uncontrolled keywords: Infrared: stars, ISM: Herbig-Haro objects, ISM: jets and outflows, Stars: circumstellar matter
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Divisions: Faculties > Sciences > School of Physical Sciences > Centre for Astrophysics and Planetary Sciences
Depositing User: Giles Tarver
Date Deposited: 11 Aug 2015 09:41 UTC
Last Modified: 29 May 2019 15:54 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/50120 (The current URI for this page, for reference purposes)
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