J/MNRAS/508/3569ivo://CDS.VizieR/J/MNRAS/508/3569doi:10.26093/cds/vizier.75083569CDSKosec P.Pinto C.Reynolds C.S.Guainazzi M.Kara E.Walton D.J.,Fabian A.C.Parker M.L.Valtchanov I.2024-11-29T20:16:37Z2024-09-16T16:11:42ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frx-ray-sourcesaccretionblack-holesneutron-starsspectroscopyspectral-energy-distributionline-intensitiesMost ultraluminous X-ray sources (ULXs) are thought to be powered by super- Eddington accretion on to stellar-mass compact objects. Accretors in this extreme regime are naturally expected to ionize copious amounts of plasma in their vicinity and launch powerful radiation-driven outflows from their discs. High spectral resolution X-ray observations [with reflection grating spectrometer (RGS) gratings onboard XMM-Newton] of a few ULXs with the best data sets indeed found complex line spectra and confirmed such extreme (0.1-0.3c) winds. However, a search for plasma signatures in a large ULX sample with a rigorous technique has never been performed, thereby preventing us from understanding their statistical properties such as the rate of occurrence, to constrain the outflow geometry, and its duty cycle. We developed a fast method for automated line detection in X-ray spectra and applied it to the full RGS ULX archive, rigorously quantifying the statistical significance of any candidate lines. Collecting the 135 most significant features detected in 89 observations of 19 objects, we created the first catalogue of spectral lines detected in soft X-ray ULX spectra. We found that the detected emission lines are concentrated around known rest-frame elemental transitions and thus originate from low- velocity material. The absorption lines instead avoid these transitions, suggesting they were imprinted by blueshifted outflows. Such winds therefore appear common among the ULX population. Additionally, we found that spectrally hard ULXs show fewer line detections than soft ULXs, indicating some difference in their accretion geometry and orientation, possibly causing overionization of plasma by the harder spectral energy distributions of harder ULXs.2021MNRAS.508.3569Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/508/3569CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/508/3569https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/508/3569http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/508/3569https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/508/3569https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/508/3569http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/508/3569GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/508/3569/source (List of the objects used in this study)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/508/3569/source?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/508/3569/source?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/508/3569/source?GETtext/xml+votable180.050000true213.1633333-65.39286110.0055555555555555560/https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/508/3569?format=asciiX-raydefaultJ/MNRAS/508/3569/sourceList of the objects used in this studyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject name (source)meta.id;meta.maincharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainSNameSimbad namemeta.idcharJ/MNRAS/508/3569/tableThe 135 strongest detected spectral line featuresE_EWMean upper errorbar of Eflux (E_eqwidth)keVstat.error;stat.maxdoubleApproachName of the approach based on the observations (approach)meta.code;obscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject name (source) (1)meta.id;meta.maincharLambdaObservational wavelength of the line feature (wavelength)0.1nmem.wl;spect.linedoubleEnergyObservational photon energy of the line feature (energy)keVphys.energy;phys.atmol.leveldoubleWidthVelocity width at which the line shows the strongest cross-correlation (turb_vel)km/sspect.line.widthdoublepvalThe true-false positive rate of the line feature (true_pval)stat.fit.goodnessdoubleSigSignificance of the line feature (true_sig)stat.fit.goodnessdoubleRCThe renormalized correlation of the line feature (ren_cor)stat.fit.goodnessdoublespvalThe single trial false positive rate of the line feature (s_pval)stat.fit.goodnessdoubleSTSThe single trial significance (STS)stat.fit.goodnessdoubledcstatThe {Delta}C-stat fit improvement value obtained upon directly fitting the feature in the spex fitting package (del_cstat) (2)stat.fit;meta.modelleddoublePfluxThe photon flux of the line feature (phot_flux)ph.cm**-2.s**-1phot.flux;spect.linedoublee_PfluxMean lower errorbar of Pflux (e_photflux)ph.cm**-2.s**-1stat.errordoubleE_PfluxMean upper errorbar of Pflux (E_photflux)ph.cm**-2.s**-1stat.error;stat.maxdoubleEfluxLine energy flux (en_flux)erg.cm**-2.s**-1phot.fluxdoublee_EfluxMean lower errorbar of Eflux (e_enflux)erg.cm**-2.s**-1stat.errordoubleE_EfluxMean upper errorbar of Pflux (E_enflux)erg.cm**-2.s**-1stat.error;stat.maxdoubleEWThe line equivalent width (eq_width)keVspect.line.eqWidthdoublee_EWMean lower errorbar of Eflux (e_eqwidth)keVstat.error;spect.line.eqWidthdouble