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

        Which feedback mechanisms dominate in the high-pressure environment of the Central Molecular Zone?

        View/Open
        staa2719.pdf (PDF, 2Mb)
        Author
        Barnes, Ashley T
        Longmore, Steven N
        Dale, James
        Krumholz, Mark R.
        Kruijssen, J. M.Diederik
        Bigiel, Frank
        Attention
        2299/23182
        Abstract
        Supernovae (SNe) dominate the energy and momentum budget of stellar feedback, but the efficiency with which they couple to the interstellar medium (ISM) depends strongly on how effectively early, pre-SN feedback clears dense gas from star-forming regions. There are observational constraints on the magnitudes and timescales of early stellar feedback in low ISM pressure environments, yet no such constraints exist for more cosmologically typical high ISM pressure environments. In this paper, we determine the mechanisms dominating the expansion of H ii regions as a function of size-scale and evolutionary time within the high-pressure (P/kB ∼ 107 − 8 K cm−3) environment in the inner 100 pc of the Milky Way. We calculate the thermal pressure from the warm ionised (PHII; 104 K) gas, direct radiation pressure (Pdir), and dust processed radiation pressure (PIR). We find that (1) Pdir dominates the expansion on small scales and at early times (0.01-0.1 pc; <0.1 Myr); (2) the expansion is driven by PHII on large scales at later evolutionary stages (>0.1 pc; >1 Myr); (3) during the first ≲ 1 Myr of growth, but not thereafter, either PIR or stellar wind pressure likely make a comparable contribution. Despite the high confining pressure of the environment, natal star-forming gas is efficiently cleared to radii of several pc within ∼ 2 Myr, i.e. before the first SNe explode. This ‘pre-processing’ means that subsequent SNe will explode into low density gas, so their energy and momentum will efficiently couple to the ISM. We find the H ii regions expand to a radius of ∼ 3pc, at which point they have internal pressures equal with the surrounding external pressure. A comparison with H ii regions in lower pressure environments shows that the maximum size of all H ii regions is set by pressure equilibrium with the ambient ISM.
        Publication date
        2020-09-08
        Published in
        Monthly Notices of the Royal Astronomical Society
        Published version
        https://doi.org/10.1093/mnras/staa2719
        Other links
        http://hdl.handle.net/2299/23182
        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