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The near-infrared excitation of the HH 211 protostellar outflow

O'Connell, Barry, Smith, Michael D., Froebrich, Dirk, Davis, Chris J., Eisloffel, Jochen (2005) The near-infrared excitation of the HH 211 protostellar outflow. Astronomy & Astrophysics, 431 (1). pp. 223-234. ISSN 0004-6361. (doi:10.1051/0004-6361:20041821) (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:49579)

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.
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The protostellar outflow HH 211 is of considerable interest since it is extremely young and highly collimated. Here, we explore the outflow through imaging and spectroscopy in the near-infrared to determine if there are further diagnostic signatures of youth. We confirm the detection of a near-infrared continuum of unknown origin. We propose that it is emitted by the driving millimeter source, escapes the core through tunnels, and illuminates features aligning the outflow. Narrow-band flux measurements of these features contain an unusually large amount of continuum emission. [Fell] emission at 1.644 μm has been detected and is restricted to isolated condensations. However, the characteristics of vibrational excitation of molecular hydrogen resemble those of older molecular outflows. We attempt to model the ordered structure of the western outflow as a series of shocks, finding that bow shocks with J-type dissociative apices and C-type flanks are consistent. Moreover, essentially the same conditions are predicted for all three bows except for a systematic reduction in speed and density with distance from the driving source. We find increased K-band extinctions in the bright regions as high as 2.9 mag and suggest that the bow shocks become visible where the outflow impacts on dense clumps of cloud material. We propose that the outflow is carved out by episodes of pulsating jets. The jets, driven by central explosive events, are responsible for excavating a central tunnel through which radiation temporarily penetrates.

Item Type: Article
DOI/Identification number: 10.1051/0004-6361:20041821
Uncontrolled keywords: Infrared: ISM, ISM: Herbig-Haro objects, ISM: individual objects: HH 211, Ism: jets and outflows, Stars: circumstellar matter, Carbon monoxide, Clouds, Galaxies, Imaging techniques, Molecules, Space research, Isolated condensations, Molecular hydrogen flows, Protostars, Astrophysics
Subjects: Q Science > QB Astronomy
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: Giles Tarver
Date Deposited: 17 Jul 2015 14:29 UTC
Last Modified: 16 Nov 2021 10:20 UTC
Resource URI: (The current URI for this page, for reference purposes)

University of Kent Author Information

Smith, Michael D..

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Froebrich, Dirk.

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