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

        X-ray emission from an expanding supergiant shell in IC 2574

        View/Open
        901060.pdf (PDF, 1Mb)
        Author
        Walter, F.
        Kerp, J.
        Duric, N.
        Brinks, E.
        Klein, U.
        Attention
        2299/975
        Abstract
        We present a multiwavelength study of a supergiant shell within the violent interstellar medium of the nearby dwarf galaxy IC 2574, which is a member of the M81 group of galaxies. Neutral hydrogen (H i) observations obtained with the Very Large Array (VLA) reveal a prominent expanding supergiant H i shell in the northeast quadrant of IC 2574 which is thought to be produced by the combined effects of stellar winds and supernova explosions. It measures roughly 1000#500 pc in size and is expanding at »25 km s21. The H i data suggest an age of »1.4#106 yr; the energy input must have been of order (2.651)#1053 ergs. Massive star-forming regions, as traced by Ha emission, are situated predominantly on the rim of this H i shell. This supports the view that the accumulated H i on the rim has reached densities that are high enough for secondary star formation to commence. VLA radio continuum observations at l 5 6 cm show that these star-forming regions are the main sources of radio continuum emission in this galaxy. This emission is mainly thermal in origin. Soft X-ray emission from within the H i hole is detected by a pointed ROSAT PSPC observation. The emission is resolved, coinciding in size and orientation with the H i shell. These spatial properties suggest that the emission is generated by an X-ray–emitting plasma located within the H i shell, although a contribution from X-ray binaries cannot be completely ruled out. The X-ray luminosity within the 0.11–2.4 keV energy range is L 5 (1.650.5)#1038 X ergs s21. The X-ray data are compatible with emission coming from a Raymond-Smith plasma at a temperature of about log (T [K]) 5 6.8 and a density of n » 0.03 cm23. The energy content of the coronal gas corresponds e to (452)#1053 ergs, or broadly in agreement with the energy input derived on the basis of the H i observations.
        Publication date
        1998
        Published in
        The Astrophysical Journal
        Other links
        http://hdl.handle.net/2299/975
        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