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dc.contributor.authorToloza, O.
dc.contributor.authorGänsicke, B. T.
dc.contributor.authorHermes, J. J.
dc.contributor.authorTownsley, D. M.
dc.contributor.authorSchreiber, M. R.
dc.contributor.authorSzkody, P.
dc.contributor.authorPala, A.
dc.contributor.authorBeuermann, K.
dc.contributor.authorBildsten, L.
dc.contributor.authorBreedt, E.
dc.contributor.authorCook, M.
dc.contributor.authorGodon, P.
dc.contributor.authorHenden, A. A.
dc.contributor.authorHubeny, I.
dc.contributor.authorKnigge, C.
dc.contributor.authorLong, K. S.
dc.contributor.authorMarsh, T. R.
dc.contributor.authorde Martino, D.
dc.contributor.authorMukadam, A. S.
dc.contributor.authorMyers, G.
dc.contributor.authorNelson, P.
dc.contributor.authorOksanen, A.
dc.contributor.authorPatterson, J.
dc.contributor.authorSion, E. M.
dc.contributor.authorZorotovic, M.
dc.date.accessioned2016-11-29T17:02:40Z
dc.date.available2016-11-29T17:02:40Z
dc.date.issued2016-07-11
dc.identifier.citationGW Librae: a unique laboratory for pulsations in an accreting white dwarf 2016, 459 (4):3929 Monthly Notices of the Royal Astronomical Societyen
dc.identifier.issn0035-8711
dc.identifier.issn1365-2966
dc.identifier.doi10.1093/mnras/stw838
dc.identifier.urihttp://hdl.handle.net/10150/621433
dc.description.abstractNon-radial pulsations have been identified in a number of accreting white dwarfs in cataclysmic variables. These stars offer insight into the excitation of pulsation modes in atmospheres with mixed compositions of hydrogen, helium, and metals, and the response of these modes to changes in the white dwarf temperature. Among all pulsating cataclysmic variable white dwarfs, GW Librae stands out by having a well-established observational record of three independent pulsation modes that disappeared when the white dwarf temperature rose dramatically following its 2007 accretion outburst. Our analysis of Hubble Space Telescope (HST) ultraviolet spectroscopy taken in 2002, 2010, and 2011, showed that pulsations produce variations in the white dwarf effective temperature as predicted by theory. Additionally in 2013 May, we obtained new HST/Cosmic Origin Spectrograph ultraviolet observations that displayed unexpected behaviour: besides showing variability at a parts per thousand integral 275 s, which is close to the post-outburst pulsations detected with HST in 2010 and 2011, the white dwarf exhibits high-amplitude variability on an a parts per thousand integral 4.4 h time-scale. We demonstrate that this variability is produced by an increase of the temperature of a region on white dwarf covering up to a parts per thousand integral 30 per cent of the visible white dwarf surface. We argue against a short-lived accretion episode as the explanation of such heating, and discuss this event in the context of non-radial pulsations on a rapidly rotating star.
dc.description.sponsorshipEuropean Research Council under the European Union [320964]; NASA through Hubble Fellowship - Space Telescope Science Institute [HST-HF2-51357.001-A]; NASA [NAS5-26555]; Fondecyt [3130559, 1141269]; Millennium Nucleus [RC130007]; CONICYT becas-CONICYT/Becade-Doctorado-en-el-extranjero [72140362]en
dc.language.isoenen
dc.publisherOXFORD UNIV PRESSen
dc.relation.urlhttp://mnras.oxfordjournals.org/lookup/doi/10.1093/mnras/stw838en
dc.rights© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Societyen
dc.subjectbinaries: closeen
dc.subjectstars: individual: GW Libraeen
dc.subjectstars: variables: generalen
dc.subjectwhite dwarfsen
dc.titleGW Librae: a unique laboratory for pulsations in an accreting white dwarfen
dc.typeArticleen
dc.contributor.departmentUniv Arizona, Dept Astron, Steward Observen
dc.identifier.journalMonthly Notices of the Royal Astronomical Societyen
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
refterms.dateFOA2018-06-27T04:18:26Z
html.description.abstractNon-radial pulsations have been identified in a number of accreting white dwarfs in cataclysmic variables. These stars offer insight into the excitation of pulsation modes in atmospheres with mixed compositions of hydrogen, helium, and metals, and the response of these modes to changes in the white dwarf temperature. Among all pulsating cataclysmic variable white dwarfs, GW Librae stands out by having a well-established observational record of three independent pulsation modes that disappeared when the white dwarf temperature rose dramatically following its 2007 accretion outburst. Our analysis of Hubble Space Telescope (HST) ultraviolet spectroscopy taken in 2002, 2010, and 2011, showed that pulsations produce variations in the white dwarf effective temperature as predicted by theory. Additionally in 2013 May, we obtained new HST/Cosmic Origin Spectrograph ultraviolet observations that displayed unexpected behaviour: besides showing variability at a parts per thousand integral 275 s, which is close to the post-outburst pulsations detected with HST in 2010 and 2011, the white dwarf exhibits high-amplitude variability on an a parts per thousand integral 4.4 h time-scale. We demonstrate that this variability is produced by an increase of the temperature of a region on white dwarf covering up to a parts per thousand integral 30 per cent of the visible white dwarf surface. We argue against a short-lived accretion episode as the explanation of such heating, and discuss this event in the context of non-radial pulsations on a rapidly rotating star.


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