J/MNRAS/515/5993ivo://CDS.VizieR/J/MNRAS/515/5993CDSDrew J.E.Blake-Parsons F.Mohr-Smith M.2025-09-17T14:17:19Z2025-09-17T14:38:00ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyob-starsvisible-astronomyspectroscopyastrometryphotometryeffective-temperatureextinctionradial-velocitytrigonometric-parallaxproper-motionsstellar-distanceMassive O and early B stars are important markers of recent star formation and exert a significant influence on their environments during their short lives via photoionization and winds and when they explode as supernovae. In the Milky Way, they can be detected at great distances but often lie behind large dust columns, making detection at short wavelengths difficult. In this study, the use of the less extinguished far-red spectrum (8400-8800 {AA}) for radial velocity measurement is examined. Results are reported for a sample of 164 confirmed OB stars within a 2{deg} field positioned on the Carina Arm. Most stars are at distances between 3 and 6 kpc, and Westerlund 2 is at the field edge. The measured radial velocities have errors concentrated in the 3-10 km.s^-1^ range, with a systematic uncertainty of 2-3 km.s^-1^. These are combined with Gaia-mission astrometry to allow full space motions to be constructed. Up to 22 stars are likely to be runaways, although 8 of them are as likely to be interloping (so far undetected) binaries. The mean azimuthal motion of the sample fits in with recent measurements of Galactic disc rotation. In the Galactocentric radial direction, the mean motion indicates modest infall at a speed of ~10 km.s^-1^. This experiment shows that weak Paschen lines in the far-red can yield credible radial velocity determination, offering the prospect of exploring OB-star kinematics over much more of the Galactic disc than has hitherto been possible.2022MNRAS.515.5993Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/515/5993CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/465/1807 : Deep OB star population in Carina (Mohr-Smith+, 2017)II/341 : VPHAS+ DR2 survey (Drew+, 2016)I/350 : Gaia EDR3 (Gaia Collaboration, 2020)J/MNRAS/485/2312 : Outer Galactic disk A and F stars space motionsJ/ApJ/885/131 : ~200 high-mass SFR plx & proper motion with VLBIJ/MNRAS/450/3855 : New OB star candidates in Carina Arm (Mohr-Smith+, 2015)J/MNRAS/508/4952 : OB stars in Carina Arm (Drew+, 2021)J/MNRAS/486/1034 : O stars of the Galactic starburst NGC 3603 (Drew+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/515/5993https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/515/5993http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/515/5993https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/515/5993https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/515/5993http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/515/5993GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/515/5993/tablea1 (Parameters and measurements of our stars sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/515/5993/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/515/5993/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/515/5993/tablea1?GETtext/xml+votable180.050000true155.51034806-58.043978890.0055555555555555565/9335 6/38018 38024 38026https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/515/5993?format=asciiOpticaldefaultJ/MNRAS/515/5993/tablea1Parameters and measurements of our stars samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension (J2000) (RA_J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (DEC_J2000)degpos.eq.dec;meta.mainpmDEProper motion in declination from Gaia EDR3 (pmDE)mas/yrpos.pm;pos.eq.decfloate_pmDEUncertainty of pmDE (e_pmDE)mas/yrstat.error;pos.pm;pos.eq.decfloatpmlGalactic longitudinal proper motion (pml)mas/yrpos.pm;pos.galacticdoublee_pmlUncertainty of pml (e_pml)mas/yrstat.errordoublepmbGalactic latitudinal proper motion (pmb)mas/yrpos.pm;pos.galacticdoubleGLONGalactic longitude in IAU 1958 system (GLON)degpos.galactic.lonGLATGalactic latitude in IAU 1958 system (GLAT)degpos.galactic.latdoublegmagThe g band AB magnitude from VPHAS OB star catalogue of Mohr-Smith (2017MNRAS.465.1807M, Cat. J/MNRAS/465/1807) (g)magphot.mag;em.opt.Bfloate_gmagMean random error of gmag (e_g)magstat.error;phot.magfloatlog(Teff)Estimated median 50th percentile effective temperature from photometry (logTeff)log(K)phys.temperature.effective;stat.median;photdoubleE_log(Teff)Upper uncertainty 84th percentile of log (Teff) (eu_logTeff)log(K)stat.error;stat.maxdoublee_log(Teff)Lower uncertainty 16th percentile of log (Teff) (el_logTeff)log(K)stat.error;stat.mindoubleA0Estimated median 50th percentile extinction from photometry (A0)magphys.absorption;stat.medianfloatE_A0Upper uncertainty 84th percentile of A0 (eu_A0)magstat.error;stat.maxfloate_A0Lower uncertainty 16th percentile of A0 (el_A0)magstat.error;stat.minfloatRvEstimated median 50th percentile extinction law paremeter from photometry (Rv)phys.absorption;stat.medianfloatE_RvUpper uncertainty 84th percentile of Rv (eu_Rv)stat.error;stat.maxfloate_RvLower uncertainty 16th percentile of Rv (el_Rv)stat.error;stat.minfloatlog(Teff)sp? Estimated median 50th percentile effective temperature from spectroscopy (speclogTeff)log(K)phys.temperature.effective;stat.mediandoublenullableE_log(Teff)sp? Upper uncertainty 84th percentile of log(Teff)sp (eu_speclogTeff)log(K)stat.error;stat.maxdoublenullablee_log(Teff)sp? Lower uncertainty 16th percentile of log(Teff)sp (el_speclogTeff)log(K)stat.error;stat.mindoublenullablelog(g)sp? Estimated median 50th percentile surface gravity from spectroscopy (logg)log(cm.s**-2)phys.gravity;stat.mediandoublenullableE_log(g)sp? Upper uncertainty 84th percentile of log(g)sp (eu_logg)log(cm.s**-2)stat.error;stat.maxdoublenullablee_log(g)sp? Lower uncertainty 16th percentile of log(g)sp (el_logg)log(cm.s**-2)stat.error;stat.mindoublenullablevsini? Estimated median 50th percentile projected rotation speed (vsini)km/sphys.veloc.rotat;stat.medianintnullableE_vsini? Upper uncertainty 84th percentile of vsini (eu_vsini)km/sstat.error;stat.maxintnullableVPHASDR2meta.ref.urlchare_vsini? Lower uncertainty 16th percentile of vsini (el_vsini)km/sstat.error;stat.minintnullableLambdaPa12Spectroscopic measured Paschen 12 line from combined Pa12 and Pa13 fits (Pa_lambda)0.1nmem.wl;em.opt.I;spect.linedoublee_LambdaPa12Fit uncertainty of LambdaPa12 (e_Pa_lambda)0.1nmstat.errorfloatRVPaHeliocentric radial velocity from LambdaPa12 measurements (Pa_vel_hc)km/sspect.dopplerVeloc;pos.heliocentricdoublee_RVPaMean error of RVPa (e_Pa_vel_hc)km/sstat.errordoubleGaiaEDR3Gaia EDR3 source identifier number (EDR3Name)meta.id.assocPlxParallax from Gaia EDR3 (Plx)maspos.parallaxfloate_PlxUncertainty of Plx (e_Plx)masstat.error;pos.parallaxfloatPlx/e_PlxParallax to uncertainty ratio (RPlx)stat.error;pos.parallax;arith.ratiofloatpmRAProper motion in right ascension from Gaia EDR3 (pmRA)mas/yrpos.pm;pos.eq.rafloate_pmRAUncertainty of pmRA (e_pmRA)mas/yrstat.error;pos.pm;pos.eq.rafloate_pmbUncertainty of pmb (e_pmb)mas/yrstat.errordoubleDEstimated median 50th distance from EDSD method with an offset 0.030 mas and a length scale of 2.0 kpc (D_2.0) (1)kpcpos.distance;stat.median;meta.modelleddoubleE_DUpper uncertainty 84th percentile of D (eu_D_2.0)kpcstat.error;stat.maxdoublee_D[] Lower uncertainty 16th percentile of D (el_D_2.0)kpcstat.error;stat.mindoublevRGalactocentric radial velocity (v_R)km/sspect.dopplerVeloc;pos.galactocentricdoublee_vRError of vR (e_v_r)km/sstat.errordoublevphiGalactocentric azimuthal velocity (v_phi)km/sphys.veloc;pos.galactocentricdoublee_vphiError of vphi (e_v_phi)km/sstat.errordoublevzGalactocentric out of the galactic plane velocity (v_z)km/sphys.veloc;pos.galactocentricdoublee_vzError of vz (e_v_z)km/sstat.errordoubleDrew2021meta.ref.urlcharNameStar name designation as (VPHAS_OE_NNNNN) (Starname)meta.id;meta.maincharSpectrumSpectrum from AAT observations provide by Mohr-Smith et al. 2017MNRAS.465.1807M, Cat. J/MNRAS/465/1807meta.ref.urlcharSimbadNameSimbad column added by the CDSmeta.idcharnullable