Curtin University Homepage
  • Library
  • Help
    • Admin

    espace - Curtin’s institutional repository

    JavaScript is disabled for your browser. Some features of this site may not work without it.
    View Item 
    • espace Home
    • espace
    • Curtin Research Publications
    • View Item
    • espace Home
    • espace
    • Curtin Research Publications
    • View Item

    The fading of two transient ultraluminous x-ray sources to below the stellar mass Eddington limit

    193418_193418.pdf (307.2Kb)
    Access Status
    Open access
    Authors
    Burke, M.
    Kraft, R.
    Soria, Roberto
    Maccarone, T.
    Raychaudhury, S.
    Sivakoff, G.
    Birkinshaw, M.
    Brassington, N.
    Forman, W.
    Hardcastle, M.
    Jones, C.
    Murray, S.
    Worrall, D.
    Date
    2013
    Type
    Journal Article
    
    Metadata
    Show full item record
    Citation
    Burke, Mark J. and Kraft, Ralph P. and Soria, Roberto and Maccarone, Thomas J. and Raychaudhury, Somak and Sivakoff, Gregory R. and Birkinshaw, Mark and Brassington, Nicola J. and Forman, William R. and Hardcastle, Martin J. and Jones, Christine and Murray, Stephen S. and Worrall, Diana M. 2013. The fading of two transient ultraluminous x-ray sources to below the stellar mass Eddington limit. Astrophysical Journal. 775 (1): pp. 1-9.
    Source Title
    Astrophysical Journal
    DOI
    10.1088/0004-637X/775/1/21
    ISSN
    0004-637X
    Remarks

    This is an author-created, un-copy edited version of an article accepted for publication in the Astrophysical Journal. The publisher is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://doi.org/10.1088/0004-637X/775/1/21

    URI
    http://hdl.handle.net/20.500.11937/30082
    Collection
    • Curtin Research Publications
    Abstract

    We report new detections of the two transient ultraluminous X-ray sources (ULXs) in NGC 5128 from an ongoing series of Chandra observations. Both sources have previously been observed Lx (2-3) × ~1039 erg s–1, at the lower end of the ULX luminosity range. The new observations allow us to study these sources in the luminosity regime frequented by the Galactic black hole X-ray binaries (BH XBs). We present the recent lightcurves of both ULXs. 1RXH J132519.8-430312 (ULX1) was observed at Lx ≈ 1 × 1038 erg s–1, while CXOU J132518.2-430304 (ULX2) declined to Lx ≈ 2 × 1037 erg s–1 and then lingered at this luminosity for hundreds of days. We show that a reasonable upper limit for both duty cycles is 0.2, with a lower limit of 0.12 for ULX2. This duty cycle is larger than anticipated for transient ULXs in old stellar populations. By fitting simple spectral models in an observation with ~50 counts we recover properties consistent with Galactic BH XBs, but inconclusive as to the spectral state. We utilize quantile analyses to demonstrate that the spectra are generally soft, and that in one observation the spectrum of ULX2 is inconsistent with a canonical hard state at >95% confidence. This is contrary to what would be expected of an accreting intermediate mass black hole primary, which we would expect to be in the hard state at these luminosities. We discuss the paucity of transient ULXs discovered in early-type galaxies and excogitate explanations. We suggest that the number of transient ULXs scales with the giant and sub-giant populations, rather than the total number of XBs.

    Related items

    Showing items related by title, author, creator and subject.

    • Discovery of a radio transient in M81
      Anderson, Gemma ; Miller-Jones, James ; Middleton, M.J.; Soria, Roberto ; Swartz, D.A.; Urquhart, Ryan ; Hurley-Walker, Natasha ; Hancock, Paul ; Fender, R.P.; Gandhi, P.; Markoff, S.; Roberts, T.P. (2019)
      We report the discovery of a radio transient in the spiral galaxy M81. The transient was detected in early 2015 as part of a two-year survey of M81 made up of 12 epochs using the Karl G. Jansky Very Large Array. While ...
    • The black hole candidate MAXI J1659-152 in and towards quiescence in X-ray and radio
      Jonker, P.; Miller-Jones, James; Homan, J.; Tomsick, J.; Fender, R.; Kaaret, P.; Markoff, S.; Gallo, E. (2012)
      In this paper we report on Expanded Very Large Array radio and Chandra and Swift X-ray observations of the outburst decay of the transient black hole candidate MAXI J1659-152 in 2011. We discuss the distance to the source ...
    • A mass of less than 15 solar masses for the black hole in an ultraluminous X-ray source
      Motch, C.; Pakull, M.; Soria, Roberto; Grisé, F.; Pietrzynski, G. (2014)
      Most ultraluminous X-ray sources have a typical set of properties not seen in Galactic stellar-mass black holes. They have luminosities of more than 3 × 10 39 ergs per second, unusually soft X-ray components (with a typical ...
    Advanced search

    Browse

    Communities & CollectionsIssue DateAuthorTitleSubjectDocument TypeThis CollectionIssue DateAuthorTitleSubjectDocument Type

    My Account

    Admin

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Follow Curtin

    • 
    • 
    • 
    • 
    • 

    CRICOS Provider Code: 00301JABN: 99 143 842 569TEQSA: PRV12158

    Copyright | Disclaimer | Privacy statement | Accessibility

    Curtin would like to pay respect to the Aboriginal and Torres Strait Islander members of our community by acknowledging the traditional owners of the land on which the Perth campus is located, the Whadjuk people of the Nyungar Nation; and on our Kalgoorlie campus, the Wongutha people of the North-Eastern Goldfields.