University of Hertfordshire Research Archive

        JavaScript is disabled for your browser. Some features of this site may not work without it.

        Browse

        All of UHRABy Issue DateAuthorsTitlesThis CollectionBy Issue DateAuthorsTitles

        Arkivum Files

        My Downloads
        View Item 
        • UHRA Home
        • University of Hertfordshire
        • Research publications
        • View Item
        • UHRA Home
        • University of Hertfordshire
        • Research publications
        • View Item

        Resolving the ISM at the peak of cosmic star formation with ALMA - The distribution of CO and dust continuum in z~2.5 sub-millimetre galaxies

        View/Open
        Rivera_2018_ApJ_863_56.pdf (PDF, 2Mb)
        Author
        Rivera, Gabriela Calistro
        Hodge, J. A.
        Smail, Ian
        Swinbank, A. M.
        Weiß, A.
        Wardlow, J. L.
        Walter, F.
        Rybak, M.
        Chen, Chian-Chou
        Brandt, W. N.
        Coppin, K.
        Cunha, E. da
        Dannerbauer, H.
        Greve, T. R.
        Karim, A.
        Knudsen, K. K.
        Schinnerer, E.
        Venemans, B.
        Werf, P. P. van der
        Attention
        2299/20921
        Abstract
        We use Atacama Large Millimeter Array (ALMA) observations of four submillimeter galaxies (SMGs) at z ~ 2–3 to investigate the spatially resolved properties of the interstellar medium (ISM) at scales of 1–5 kpc (01–06). The velocity fields of our sources, traced by the 12CO(J = 3–2) emission, are consistent with disk rotation to the first order, implying average dynamical masses of ~3  ×  1011  within two half-light radii. Through a Bayesian approach we investigate the uncertainties inherent to dynamically constraining total gas masses. We explore the covariance between the stellar mass-to-light ratio and CO-to-H2 conversion factor, α CO, finding values of for dark matter fractions of 15%. We show that the resolved spatial distribution of the gas and dust continuum can be uncorrelated to the stellar emission, challenging energy balance assumptions in global SED fitting. Through a stacking analysis of the resolved radial profiles of the CO(3–2), stellar, and dust continuum emission in SMG samples, we find that the cool molecular gas emission in these sources (radii ~5–14 kpc) is clearly more extended than the rest-frame ~250 μm dust continuum by a factor >2. We propose that assuming a constant dust-to-gas ratio, this apparent difference in sizes can be explained by temperature and optical depth gradients alone. Our results suggest that caution must be exercised when extrapolating morphological properties of dust continuum observations to conclusions about the molecular gas phase of the interstellar medium (ISM).
        Publication date
        2018-08-10
        Published in
        The Astrophysical Journal
        Published version
        https://doi.org/10.3847/1538-4357/aacffa
        Other links
        http://hdl.handle.net/2299/20921
        Metadata
        Show full item record
        Keep in touch

        © 2019 University of Hertfordshire

        I want to...

        • Apply for a course
        • Download a Prospectus
        • Find a job at the University
        • Make a complaint
        • Contact the Press Office

        Go to...

        • Accommodation booking
        • Your student record
        • Bayfordbury
        • KASPAR
        • UH Arts

        The small print

        • Terms of use
        • Privacy and cookies
        • Criminal Finances Act 2017
        • Modern Slavery Act 2015
        • Sitemap

        Find/Contact us

        • T: +44 (0)1707 284000
        • E: ask@herts.ac.uk
        • Where to find us
        • Parking
        • hr
        • qaa
        • stonewall
        • AMBA
        • ECU Race Charter
        • disability confident
        • AthenaSwan