J/A+A/690/A368ivo://CDS.VizieR/J/A+A/690/A368doi:10.26093/cds/vizier/bc-nj/ldgiCDSGeier S.Heber U.Irrgang A.Dorsch M.Bastian A.Neunteufel P.,Kupfer T.Bloemen S.Kreuzer S.Moller L.Schindewolf M.Schneider D.,Ziegerer E.Pelisoli I.Schaffenroth V.Barlow B.N.Raddi R.,Geier S.J.Reindl N.Rauch T.Nemeth P.Gansicke B.T.2026-07-03T06:36:13Z2025-05-05T13:54:14ZCDS support team

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

cds-question@unistra.frsubdwarf-starssupernovaeeffective-temperaturestellar-radiiHot subdwarfs (sdO/B) are the stripped helium cores of red giants formed via binary interactions. Close hot subdwarf binaries with massive white dwarf companions have been proposed as possible progenitors of thermonuclear supernovae type Ia (SN Ia). If the supernova is triggered by stable mass transfer from the helium star, the companion should survive the explosion and should be accelerated to high velocities. The hypervelocity star US 708 is regarded as the prototype for such an ejected companion. To find more of those objects we conducted an extensive spectroscopic survey. Candidates for such fast stars have been selected from the spectroscopic database of the Sloan Digital Sky Survey (SDSS) and several ground-based proper-motion surveys. Follow-up spectroscopy has been obtained with several 4m- to 10m-class telescopes. Combining the results from quantitative spectroscopic analyses with space-based astrometry from Gaia Early Data Release 3 (EDR3) we determined the atmospheric and kinematic parameters of 53 fast hot subdwarf stars. None of these stars is unbound to the Galaxy, although some have Galactic restframe velocities close to the Galactic escape velocity. 21 stars are apparently single objects, that crossed the Galactic disc within their lifetimes in the sdO/B stage and could be regarded as potential candidates for the SN Ia ejection scenario. However, the properties of the full sample are more consistent with a pure old Galactic halo population. We therefore conclude that the fast sdO/B stars we found are likely to be extreme halo stars.2024A&A...690A.368Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/690/A368CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/690/A368https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/690/A368http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/690/A368https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/690/A368https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/690/A368http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/690/A368GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/690/A368/tablea3 (Classifications and spectroscopic parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/690/A368/tablea3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/690/A368/tablea3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/690/A368/tablea3?GETtext/xml+votable180.050000true36.09256810.05374810.0055555555555555566/4150 4329 4518 4753 5150 5369 6497 7260 8211 8342 8369 8444 8833 9155 9217 9285 9500 9520 9775 9991 10158 10238 10643 10766 10935 12353 12398 12657 17769 18686 19052 19135 19381 25970 25976 26317 26360 26374 26553 26615 27229 27728 27918 28143 28423 28440 31448 31609 32061 32483 32525 49079 49121https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/690/A368?format=asciidefaultJ/A+A/690/A368/tablea1Spectroscopic data overviewrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSDSS name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharSDSS? Number of SDSS available spectrameta.numberintnullableBOSS? Number of BOSS available spectrameta.numberintnullableISIS? Number of ISIS available spectrameta.numberintnullableLAMOST? Number of LAMOST available spectrameta.numberintnullableXSHO? Number of XSHO available spectrameta.numberintnullableFORS1? Number of FORS1 available spectrameta.numberintnullableEFOSC2? Number of EFOSC2 available spectrameta.numberintnullableDBSP? Number of DBSP available spectrameta.numberintnullableTWIN? Number of TWIN available spectrameta.numberintnullableLRIS? Number of LRIS available spectrameta.numberintnullableJ/A+A/690/A368/tablea3Classifications and spectroscopic parametersSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSDSS name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharn_Name[a] Note on SDSS name (1)meta.notecharClassSpectral types (defined in Section 4.1)src.spTypecharTeffEffective temperatureKphys.temperature.effectiveintE_TeffEffective temperature error (upper value) (2)Kstat.error;stat.maxinte_TeffEffective temperature error (lower value) (2)Kstat.error;phys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloatE_loggSurface gravity error (upper value) (2)log(cm.s**-2)stat.error;stat.maxfloate_loggSurface gravity error (lower value) (2)log(cm.s**-2)stat.errorfloatl_logn(He/H)Limit flag on logn(He/H)meta.code.errorcharlogn(He/H)Helium abundancephys.abund.YfloatE_logn(He/H)? Helium abundance (upper value) (2)stat.error;stat.maxfloatnullablee_logn(He/H)? Helium abundance (lower value) (2)stat.errorfloatnullableRVMean radial velocitykm/sphys.veloc;pos.heliocentricinte_RVMean radial velocity standard deviation (2)km/sstat.errorintlogplog p value to indicate radial velocity variabilitystat.fit.goodnessfloatNspecNumber of spectra usedmeta.numberintCat[1/4] Category as defined in Sect. 4.4 (3)meta.codeint_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/A+A/690/A368/tablea4Astrometric parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSDSS name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharGaiaDR3GaiaDR3 identifiermeta.idplx? Parallax (1)maspos.parallax.trigfloatnullablee_plx? Parallax errormasstat.error;pos.parallaxfloatnullablepmRAProper motion in right ascension, pmRA*cosDEmas/yrpos.pm;pos.eq.rafloate_pmRAProper motion in right ascension errormas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion in declinationmas/yrpos.pm;pos.eq.decfloate_pmDEProper motion in declination errormas/yrstat.error;pos.pm;pos.eq.decfloatJ/A+A/690/A368/tablea5Results of the SED analysisrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSDSS name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharlog(theta)Angular diameterlog(rad)phys.angSizefloatE_log(theta)Angular diameter error (upper value)log(rad)stat.error;stat.maxfloate_log(theta)Angular diameter error (lower value)log(rad)stat.errorfloatE(44-55)Interstellar reddening parameter E(44-55)magphot.color.reddFreefloatE_E(44-55)Interstellar reddening parameter E(44-55) error (upper value)magstat.error;stat.maxfloate_E(44-55)Interstellar reddening parameter E(44-55) error (lower value)magstat.errorfloatDspecSpectroscopic distancekpcpos.distancefloatE_DspecSpectroscopic distance error (upper value)kpcstat.error;stat.maxfloate_DspecSpectroscopic distance error (lower value)kpcstat.errorfloatJ/A+A/690/A368/tablea6Kinematic parameters of the fast star candidatesXX positionkpcpos.cartesian.x;pos.galacticfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSDSS name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharE_XX position error (upper value)kpcstat.error;stat.maxfloate_XX position error (lower value)kpcstat.error;pos.cartesian.xfloatYkpcpos.cartesian.y;pos.galacticfloatE_YY position error (upper value)kpcstat.error;stat.maxfloate_YY position error (lower value)kpcstat.error;pos.cartesian.yfloatZZ positionkpcpos.cartesian.z;pos.galacticfloatE_ZZ position error (upper value)kpcstat.error;stat.maxfloate_ZZ position error (lower value)kpcstat.error;src.redshiftdoubleUGalactic U velocitykm/sphys.veloc;pos.cartesian.xintE_UGalactic U velocity error (upper value)km/sstat.error;stat.maxinte_UGalactic U velocity error (lower value)km/sstat.error;pos.cartesian.xintVGalactic V velocitykm/sphys.veloc;pos.cartesian.yintE_VGalactic V velocity error (upper value)km/sstat.error;stat.maxinte_VGalactic V velocity error (lower value)km/sstat.error;pos.cartesian.yintWGalactic W velocitykm/sphys.veloc;pos.cartesian.zintE_WGalactic W velocity error (upper value)km/sstat.error;stat.maxinte_WGalactic W velocity error (lower value)km/sstat.error;pos.cartesian.zintvgrfGalactic rest-frame velocitykm/sphys.veloc;pos.galactocentricintE_vgrfGalactic rest-frame velocity error (upper value)km/sstat.error;stat.maxinte_vgrfGalactic rest-frame velocity error (lower value)km/sstat.errorintJ/A+A/690/A368/tablea7Parameters of the fast star candidates at the last Galactic disc passageeEllipticitysrc.ellipticityfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintXdiscDisc X positionkpcpos.cartesian.x;pos.galacticfloatE_XdiscDisc X position error (upper value)kpcstat.error;stat.maxfloate_XdiscDisc X position (lower value)kpcstat.errorfloatYdiscDisc Y positionkpcpos.cartesian.y;pos.galacticfloatE_YdiscDisc Y position error (upper value)kpcstat.error;stat.maxfloate_YdiscDisc Y position error (lower value)kpcstat.errorfloatRdiscDisc radiuskpcphys.size.radiusfloatE_RdiscDisc radius error (upper value)kpcstat.error;stat.maxfloate_RdiscDisc radius error (lower value)kpcstat.errorfloatVejEjection velocitykm/sphys.velocintE_VejEjection velocity error (upper value)km/sstat.error;stat.maxinte_VejEjection velocity error (lower value)km/sstat.errorinttdiscDisc ageMyrtime.agefloatE_tdiscDisc age error (upper value)Myrstat.error;stat.maxfloate_tdiscDisc age error (lower value)Myrstat.errorfloatE_eEllipticity error (upper value)stat.error;stat.maxfloate_eEllipticity error (lower value)stat.errorfloatLzAngular momentum in z-direction1000kpc.km.s**-1phys.angMomentumfloatE_LzAngular momentum in z-direction error (upper value)1000kpc.km.s**-1stat.error;stat.maxfloate_LzAngular momentum in z-direction error (lower value)1000kpc.km.s**-1stat.errorfloatNameSDSS name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.mainchar