J/A+A/664/A159ivo://CDS.VizieR/J/A+A/664/A159doi:10.26093/cds/vizier.36640159CDSMahy L.Sana H.Shenar T.Sen K.Langer N.Marchant P.,Abdul-Masih M.Banyard G.Bodensteiner J.Bowman D.M.Dsilva K.,Fabry M.Hawcroft C.Janssens S.Van Reeth T.Eldridge C.2022-11-13T17:29:43Z2022-08-25T08:49:58ZCDS support team

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

cds-question@unistra.frvariable-starsspectroscopic-binary-starsspectroscopyradial-velocityvisible-astronomyThe quest to detect dormant stellar-mass black holes (BHs) in massive binaries (i.e., OB+BH systems) is challenging, and only a few candidates have been claimed to date but must still be confirmed as such. To search for these rare objects, we study 32 Galactic O-type stars that were reported as single-lined spectroscopic binaries (SB1s) in the literature. In our sample we include Cyg X-1, which is known to host an accreting stellar-mass BH, and, HD 74194, a supergiant fast X-ray transient, in order to validate our methodology. The final goal is to characterise the nature of the unseen companions to determine if they are main-sequence (MS) stars, stripped helium stars, triples or compact objects such as neutron stars (NSs) or stellar-mass BHs. After measuring radial velocities and deriving orbital solutions for all the systems in our sample, we performed spectral disentangling to extract putative signatures of faint secondary companions from the composite spectra. We derived stellar parameters for the visible stars and estimated the mass ranges of the secondary stars using the binary mass function. Variability observed in the photometric TESS light curves was also searched for indications of the presence of putative companions, degenerate or not. In 17 of the 32 systems reported as SB1s, we extract secondary signatures, down to mass ratios of 0.15. For the 17 newly detected double-lined spectroscopic binaries (SB2s), we derive physical properties of the individual components and discuss why they have not been detected as such before. Among the remaining systems, we identify nine systems with possible NS or low-mass MS companions. For Cyg X-1 and HD 130298, we are not able to extract any signatures for the companions, while the minimum masses of their companions are estimated to be about 7 Msun. Our simulations show that secondaries with such a mass should be detectable from our data set, no matter their nature: MS star, stripped helium stars or even triples. While this is expected for Cyg X-1, confirming at the same time our methodology, this also strongly suggests that HD 130298 could be another candidates to host a stellar-mass BH. The quest to detect dormant stellar-mass BHs in massive binaries is far from over, and many more systems need to be scrutinised. Our analysis allows us to detect a good candidate, but confirming the BH nature of their companions will require further dedicated monitorings, sophisticated analysis techniques, and multi-wavelength observations.2022A&A...664A.159Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/664/A159CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/664/A159https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/664/A159http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/664/A159https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/664/A159https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/664/A159http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/664/A159GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/664/A159/stars (List of studied stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/664/A159/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/664/A159/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/664/A159/stars?GETtext/xml+votable180.050000true299.590333335.20161110.0055555555555555566/1040 2409 3214 3585 3755 14632 14645 14693 14741 15369 22088 22240 23360 24555 28890 28915 29089 29098 29162 31748 37333 37897 38020 38024 39238 39248 39930 41787 42417 43041https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/664/A159?format=asciiOpticaldefaultJ/A+A/664/A159/starsList of studied starsSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainPerPeriod (from tables 1 and 2 of the paper)dtime.perioddoublee_PerPeriod error (from tables 1 and 2 of the paper)dstat.errordoubleType[SB1 SB2] SB1 or SB2 (from tables 1 and 2 of the paper)src.classcharVCShow the Radial Velocity curvesmeta.ref.urlcharJ/A+A/664/A159/rvRadial velocities derived for all the stars in the paperrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharHJDHeliocentric Julian date (HJD-2450000)dtime.epochdoubleRVRadial velocity of the starkm/sphys.veloc;pos.heliocentricfloate_RV1 sigma error on the radial velocity measurementkm/sstat.errorfloat