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dc.contributor.authorBrassington, Nicola
dc.contributor.authorFabbiano, G.
dc.contributor.authorBlake, S.
dc.contributor.authorZezas, A.
dc.contributor.authorAngelini, L.
dc.contributor.authorDavies, R. L.
dc.contributor.authorGallagher, J.
dc.contributor.authorKalogera, V.
dc.contributor.authorKim, D. -W.
dc.contributor.authorKing, A. R.
dc.contributor.authorKundu, A.
dc.contributor.authorTrinchieri, G.
dc.contributor.authorZepf, S.
dc.date.accessioned2011-12-14T16:01:08Z
dc.date.available2011-12-14T16:01:08Z
dc.date.issued2010-12
dc.identifier.citationBrassington , N , Fabbiano , G , Blake , S , Zezas , A , Angelini , L , Davies , R L , Gallagher , J , Kalogera , V , Kim , D -W , King , A R , Kundu , A , Trinchieri , G & Zepf , S 2010 , ' The X-ray spectra of the luminous LMXBs in NGC 3379 : field and globular cluster sources ' , The Astrophysical Journal , vol. 725 , no. 2 , pp. 1805-1823 . https://doi.org/10.1088/0004-637X/725/2/1805
dc.identifier.issn0004-637X
dc.identifier.otherPURE: 492790
dc.identifier.otherPURE UUID: 63d659be-af28-4f74-9257-502b8851e262
dc.identifier.otherWOS: 000285501300038
dc.identifier.otherScopus: 78650159529
dc.identifier.urihttp://hdl.handle.net/2299/7269
dc.description.abstractFrom a deep multi-epoch Chandra observation of the elliptical galaxy NGC 3379 we report the spectral properties of eight luminous LMXBs (L-X > 1.2 x 10(38) erg s(-1)). We also present a set of spectral simulations, produced to aid the interpretation of low-count single-component spectral modeling. These simulations demonstrate that it is possible to infer the spectral states of X-ray binaries from these simple models and thereby constrain the properties of the source. Of the eight LMXBs studied, three reside within globular clusters (GCs) and one is a confirmed field source. Due to the nature of the luminosity cut, all sources are either neutron star (NS) binaries emitting at or above the Eddington luminosity or black hole (BH) binaries. The spectra from these sources are well described by single-component models, with parameters consistent with Galactic LMXB observations, where hard-state sources have a range in photon index of 1.5-1.9 and thermally dominant (TD) sources have inner-disk temperatures between similar to 0.7 and 1.55 keV. The large variability observed in the brightest GC source (L-X > 4 x 10(38) erg s(-1)) suggests the presence of a BH binary. At its most luminous this source is observed in a TD state with kT(in) = 1.5 keV, consistent with a BH mass of similar to 4 M-circle dot. This observation provides further evidence that GCs are able to retain such massive binaries. We also observed a source transitioning from a bright state (L-X similar to 1 x 10(39) erg s(-1)), with prominent thermal and non-thermal components, to a less luminous hard state (L-X = 3.8 x 10(38) erg s(-1), Gamma = 1.85). In its high flux emission, this source exhibits a cool-disk component of similar to 0.14 keV, similar to spectra observed in some ultraluminous X-ray sources (ULXs). Such a similarity indicates a possible link between "normal" stellar-mass BHs in a high accretion state and ULXs.en
dc.format.extent19
dc.language.isoeng
dc.relation.ispartofThe Astrophysical Journal
dc.subjectgalaxies: individual (NGC 3379)
dc.subjectX-rays: binaries
dc.subjectX-rays: galaxies
dc.subjectABSORPTION CROSS-SECTIONS
dc.subjectBLACK-HOLE ACCRETION
dc.subjectELLIPTIC GALAXIES
dc.subjectDEEP CHANDRA
dc.subjectHIGH STATE
dc.subjectMASS
dc.subjectBINARIES
dc.subjectPOPULATIONS
dc.subjectCONNECTION
dc.subjectDISTANCES
dc.titleThe X-ray spectra of the luminous LMXBs in NGC 3379 : field and globular cluster sourcesen
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
dc.contributor.institutionScience & Technology Research Institute
dc.contributor.institutionCentre for Astrophysics Research
dc.description.statusPeer reviewed
rioxxterms.versionAM
rioxxterms.versionofrecordhttps://doi.org/10.1088/0004-637X/725/2/1805
rioxxterms.typeJournal Article/Review
herts.preservation.rarelyaccessedtrue


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