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    The near-infrared outflow and cavity of the proto-brown dwarf candidate ISO-Oph 200*


    Whelan, Emma and Riaz, B. and Rouzé, B. (2018) The near-infrared outflow and cavity of the proto-brown dwarf candidate ISO-Oph 200*. Astronomy & Astrophysics, 610 (L19). ISSN 0004-6361

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    Official URL: https://doi.org/10.1051/0004-6361/201732291


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    Abstract

    In this Letter a near-infrared integral field study of a proto-brown dwarf candidate is presented. A ~0.′′5 blue-shifted outflow is detected in both H2 and [Fe II] lines at Vsys = (–35 ± 2) km s−1 and Vsys = (–51 ± 5) km s−1 respectively. In addition, slower (~±10 km s−1) H2 emission is detected out to <5.′′4, in the direction of both the blue and red-shifted outflow lobes but along a different position angle to the more compact faster emission. It is argued that the more compact emission is a jet and the extended H2 emission is tracing a cavity. The source extinction is estimated at Av = 18 ± 1 mag and the outflow extinction at Av = 9 ± 0.4 mag. The H2 outflow temperature is calculated to be 1422 ± 255 K and the electron density of the [Fe II] outflow is measured at ~10 000 cm−3. Furthermore, the mass outflow rate is estimated at Ṁout [H2] = 3.8 × 10−10 M⊙ yr−1 and Ṁout[Fe II] = 1 × 10−8 M⊙ yr−1. Ṁout[Fe II] takes a Fe depletion of ~88% into account. The depletion is investigated using the ratio of the [Fe II] 1.257 μm and [P II] 1.188 μm lines. Using the Paβ and Brγ lines and a range in stellar mass and radius Ṁacc is calculated to be (3–10) × 10−8 M⊙ yr−1. Comparing these rates puts the jet efficiency in line with predictions of magneto-centrifugal models of jet launching in low mass protostars. This is a further case of a brown dwarf outflow exhibiting analogous properties to protostellar jets.

    Item Type: Article
    Additional Information: *Based on Observations collected with SINFONI at the Very Large Telescope on Cerro Paranal (Chile), operated by the European Southern Observatory (ESO). Program ID: 097.C-0732(A).
    Keywords: brown dwarfs; stars: jets; stars: formation;
    Academic Unit: Faculty of Science and Engineering > Experimental Physics
    Item ID: 9871
    Depositing User: Emma Whelan
    Date Deposited: 03 Sep 2018 16:03
    Journal or Publication Title: Astronomy & Astrophysics
    Publisher: EDP Sciences
    Refereed: Yes
    URI:

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