J/A+A/637/A43ivo://CDS.VizieR/J/A+A/637/A43doi:10.26093/cds/vizier.36370043CDSKlutsch A.Frasca A.Guillout P.Montes D.Pineau F.-X.Grosso N.,Stelzer B.2022-08-02T14:38:42Z2020-05-13T08:13:06ZCDS support team

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

cds-question@unistra.frpre-main-sequence-starsx-ray-sourcesspectroscopyeffective-temperatureradial-velocityYoung field stars are hardly distinguishable from older ones because their space motion rapidly mixes them with the stellar population of the Galactic plane.Nevertheless, a careful target selection allows for young stars to be spotted throughout the sky. We aim to identify additional sources associated with the four young comoving stars that we discovered towards the CO Cepheus void and to provide a comprehensive view of the Cepheus association. Based on multivariate analysis methods, we have built an extended sample of 193 young star candidates, which are the optical and infrared counterparts of ROSAT All-Sky Survey and XMM-Newton X-ray sources. From optical spectroscopic observations, we measured their radial velocity with the cross-correlation technique. We derived their atmospheric parameters and projected rotational velocity with the code ROTFIT. We applied the subtraction of inactive templates to measure the lithium equivalent width, from which we infer their lithium abundance and age. Finally, we studied their kinematics using the second Gaia data release. Our sample is mainly composed of young or active stars and multiple systems. We identify two distinct populations of young stars that are spatially and kinematically separated. Those with an age between 100 and 300Myr are mostly projected towards the Galactic plane. In contrast, 23 of the 37 sources younger than 30Myr are located in the CO Cepheus void, and 21 of them belong to the stellar kinematic group that we previously reported in this sky area. We report a total of 32 bona fide members and nine candidates for this nearby (distance=157+/-10pc) young (age=10-20Myr) stellar association. According to the spatial distribution of its members, the original cluster is already dispersed and partially mixed with the local population of the Galactic plane.2020A&A...637A..43Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/637/A43CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+, 2003)I/305 : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (Lasker+, 2006)IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+, 1999)IX/29 : ROSAT All-Sky Survey Faint Source Catalog (Voges+, 2000)IX/41 : XMM-Newton Serendipitous Source Catalogue 2XMMi-DR3 (XMM-Newton, 2010)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/A+A/504/829 : Spectroscopic survey of youngest field stars (Guillout+, 2009)J/A+A/612/A96 : Spectroscopic survey of youngest field stars II (Frasca+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/637/A43https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/637/A43http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/637/A43https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/637/A43https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/637/A43http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/637/A43GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/637/A43/table1 (Main parameters of the young stars candidates available in 2009, when the was created)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/637/A43/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/637/A43/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/637/A43/table1?GETtext/xml+votable180.050000true0.5872041755.420708330.0055555555555555566/2559 2783 2793 2800 2940 2942 2987 3013 3221 3271 3314 3376 3409 3438 3462 3467 3499 3570 3576 3644 3678 3698 3742 3784 3791-3792 3800 3819 3827 3838-3839 3851 3888 3916 3928 3931 3948 3961 3976 3987 4011-4012 4087 4092 4094 7933 7935 8006 8062-8063 8087-8088 8097 8123 8126 8135 8163 8168 8177 8185 8187 10103 11495 11502 11550 11608 11613 11669 11697 11703 11725 11735 11750 11768 11889 12020 12035 12068 12106 12111 12118 12142 12173 12184 12187 12223 12245 12266 12286 14142 14165 14252 14279 14305 14312 14321 14328 15215 15218 15220 15223 15293 15303 15421 15474 15515 15541 15568 15579 15582 15589 15592 15614 15619 15650 15655 15659 15673 15679 15686 15712 15724 15732 15752 15763 15775 15810 15819 15840 15857-15858 15862 15870-15871 15890 15915 15934 15951-15952 15969 15974 15976 15998 16001 16011 16022 16047 16049 16059 16064-16066 16075 16081 16099 16132 16134 16138 16141 16145 16161 16164 16172 16177 16182 16189 16196-16197 16207 16209-16211 16213 16215 16217-16220 16231 16239 16257 16274 16278 16284 16301 16320 16324 16365 163818.650015785639275e-20 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/637/A43?format=asciiX-raydefaultJ/A+A/637/A43/table1Main parameters of the young stars candidates available in 2009, when the was createdrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget name, assigned by the authorsmeta.bib.authorcharn_TargetNotes on the target (3)meta.notechar1RXSName of the X-ray source, JHHMMSS.s+DDMMSSmeta.id;meta.mainchar2MASSName from 2MASS (Cat. II/246) catalog, JHHMMSSss+DDMMSSsmeta.idcharGSCIIName from GSCII (Cat. I/305) catalogmeta.idcharONameOther source designationmeta.idcharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainBmagB-band magnitudemagphot.mag;em.opt.Bfloatr_BmagOriginal catalog that released B-band magnitude (1)meta.ref;pos.framecharVmagV-band magnitudemagphot.mag;em.opt.Vfloatr_VmagOriginal catalog that released V-band magnitude (1)meta.ref;pos.framecharJmagJ-band magnitude from 2MASS catalogmagphot.mag;em.IR.JfloatHmagH-band magnitude from 2MASS catalogmagphot.mag;em.IR.HfloatKmagKs-band magnitude from 2MASS catalogmagphot.mag;em.IR.KfloatB-VB-V color indexmagphot.color;em.opt.B;em.opt.Vfloatn_B-V[ABC] Notes on the B-V color index (4)meta.notecharV-JV-J color indexmagphot.color;em.opt.V;em.IR.Jfloatn_V-J[AB] Notes on the V-J color index (5)meta.notecharsample[A-D] Notes on the selection method (2)meta.codechar2MASSFlagNotes on the 2MASS magnitudes (6)meta.codecharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/637/A43/table3Radial and rotational velocities, atmospheric parameters, and lithium equivalent widths derived for our targets during the surveye_logg? Error on logarithm of surface gravitycm.s**-2stat.errorfloatnullableInstSpectrographmeta.id;instrcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget name assigned by the authorsmeta.bib.authorcharApAperture number (1)meta.codecharHJDReduced Heliocentric Julian day (HJD-2400000)dtime.epoch;pos.heliocentricdoubleRV? Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricdoublenullablee_RV? Error on heliocentric radial velocitykm/sstat.errorfloatnullablevsini? Projected rotational velocitykm/sphys.veloc.rotatfloatnullablee_vsini? Error on projected rotational velocitykm/sstat.error;phys.veloc.rotatfloatnullableSpType? Spectral type in MK or HDsrc.spTypecharTeff? Effective temperatureKphys.temperature.effectiveintnullablee_Teff? Error on effective temperatureKstat.error;phys.temperature.effectiveintnullablelogg? Logarithm of surface gravitycm.s**-2phys.gravityfloatnullablee_[Fe/H]? Error on iron abundance relative to the Sunlog(Sun)stat.error;phys.abund.FefloatnullableEW(Li)? Lithium equivalent width0.1pmspect.line.eqWidthintnullablee_EW(Li)? rms uncertainty on lithium equivalent width0.1pmstat.errorintnullableNotesIndividual notes (2)meta.notechar[Fe/H]? Iron abundance relative to the Sunlog(Sun)phys.abund.FefloatnullableJ/A+A/637/A43/table4Galactic positions and space velocities of the targets, along with the astrometry in Gaia DR2, and the average RV values and lithium equivalent widths obtained during our surveyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget name assigned by the authorsmeta.bib.authorcharn_TargetNotes on the target (3)meta.notecharApAperture number (1)meta.codecharPlx? Parallaxmaspos.parallaxfloatnullablee_Plx? Standard error of parallaxmasstat.error;pos.parallaxfloatnullablepmRA? Proper motion in right ascension direction, pmRA*cosDEmas/yrpos.pm;pos.eq.radoublenullablee_pmRA? Standard error of pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE? Proper motion in declination directionmas/yrpos.pm;pos.eq.decdoublenullablee_pmDE? Standard error of pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatnullableRV? Mean Heliocentric radial velocitykm/sspect.dopplerVeloc;stat.meandoublenullablee_RV? Error on heliocentric radial velocitykm/sstat.errorfloatnullableXpos? Heliocentric position towards the Galactic anti-centerpcpos.distance;pos.cartesian.x;pos.galacticdoublenullablee_Xpos? Uncertainty on Xpospcstat.error;pos.cartesian.xdoublenullableYpos? Heliocentric position towards the Galactic rotationpcpos.cartesian.ydoublenullablee_Ypos? Uncertainty on Ypospcstat.error;pos.cartesian.ydoublenullableZpos? Heliocentric position towards the North Galactic polepcpos.cartesian.z;pos.galacticdoublenullablee_Zpos? Uncertainty on Zpospcstat.errordoublenullableUvel? Heliocentric space velocity component towards the Galactic anti-centerkm/spos.cartesian.xfloatnullablee_Uvel? Uncertainty on Uvelkm/sstat.errorfloatnullableVvel? Heliocentric space velocity component towards the Galactic rotationkm/spos.cartesian.yfloatnullablee_Vvel? Uncertainty on Vvelkm/sstat.errorfloatnullableWvel? Heliocentric space velocity component towards the North Galactic polekm/spos.cartesian.zfloatnullablee_Wvel? Uncertainty on Wvelkm/sstat.errorfloatnullableEW(Li)? Mean lithium equivalent width0.1pmspect.line.eqWidth;stat.meanfloatnullablee_EW(Li)? rms uncertainty on lithium equivalent width0.1pmstat.errorfloatnullableAv? Visible extinction estimated from the SED analysismagphys.absorptionfloatnullableNotesIndividual notes (2)meta.notecharJ/A+A/637/A43/table5*Comoving companions of our targetse_GmagStandard error of G-band mean magnitude from Gaia DR2 catalogmagstat.error;phot.magfloatRVGaia? Radial velocity in the solar barycentric reference frame from Gaia DR2 catalogkm/sphys.veloc;pos.heliocentricfloatnullablee_RVGaia? Radial velocity error from Gaia DR2 catalogkm/sstat.errorfloatnullablerho? Angular separationarcsecpos.angDistancefloatnullablee_rho? Standard error of angular separationmasstat.errorfloatnullabletheta? Position angledegpos.posAngfloatnullablee_theta? Standard error of position anglearcsecstat.error;pos.posAngdoublenullables? Projected physical separationAUpos.angDistancefloatnullablee_s? Standard error of pojected physical separationAUstat.errorfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget name assigned by the authorsmeta.bib.authorcharNameName from Gaia DR2 catalogmeta.id;meta.maincharPlxParallax from Gaia DR2 (Cat. I/345) catalogmaspos.parallaxfloate_PlxStandard error of parallaxmasstat.error;pos.parallaxfloatpmRAProper motion in right ascension direction from Gaia DR2 catalog, pmRA*cosDEmas/yrpos.pm;pos.eq.rafloate_pmRAStandard error of pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion in declination direction from Gaia DR2 catalogmas/yrpos.pm;pos.eq.decdoublee_pmDEStandard error of pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatGmagG-band mean magnitude from Gaia DR2 catalogmagphot.mag;em.optfloatSimbadSimbad column added by the CDSmeta.ref.urlchar