BIROn - Birkbeck Institutional Research Online

    Ultra-high-resolution measurements of the intrinsic line profiles of interstellar C2 towards ζ Ophiuchi and HD 169454

    Crawford, Ian and Barlow, M.J. (1996) Ultra-high-resolution measurements of the intrinsic line profiles of interstellar C2 towards ζ Ophiuchi and HD 169454. Monthly Notices of the Royal Astronomical Society 280 (3), pp. 863-867. ISSN 0035-8711.

    [img]
    Preview
    Text (Refereed)
    intrinsic line profiles.pdf - Published Version of Record

    Download (625kB) | Preview

    Abstract

    We have used the Ultra-High-Resolution Facility at the Anglo-Australian Telescope (AAT), operating at a resolution of 0.35 km s−1 (FWHM), to measure the intrinsic profiles of the Q(2) and Q(4) lines of the (2-0) Phillips band of interstellar C2 towards ζ Oph and HD 169454. The C2 lines were found to be very narrow, with intrinsic velocity dispersions (b-values) in the range 0.25−0.71 km s−1. In the case of ζ Oph, two velocity components (separation 1.10 ± 0.17 km s−1) have been resolved, and found to have rather different linewidths and rotational excitation temperatures. In the case of HD 169454, the data are consistent with a single velocity component, but the well-defined b-value (0.59 + 0.04 km s−1) and low kinetic temperature would then imply supersonic turbulent velocities. One way to avoid this conclusion is to postulate the existence of unresolved velocity structure (or a velocity gradient) within the cloud.

    Metadata

    Item Type: Article
    School: School of Science > Earth and Planetary Sciences
    Depositing User: Sarah Hall
    Date Deposited: 13 Aug 2019 14:08
    Last Modified: 13 Feb 2021 06:13
    URI: https://eprints.bbk.ac.uk/id/eprint/28548

    Statistics

    Downloads
    Activity Overview
    72Downloads
    57Hits

    Additional statistics are available via IRStats2.

    Archive Staff Only (login required)

    Edit/View Item Edit/View Item