J/AJ/166/12ivo://CDS.VizieR/J/AJ/166/12doi:10.26093/cds/vizier.51660012CDSLi Q.-Z.Huang Y.Dong X.-B.Zhang H.-W.Beers T.C.Yuan Z.2025-08-01T20:09:55Z2024-02-13T07:17:54ZCDS support team

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

cds-question@unistra.frhigh-velocity-starsinfrared-astronomyspectroscopyWe assemble a large sample of 12784 high-velocity stars with total velocity VGSR>~300km/s, selected from RAVE DR5, SDSS DR12, LAMOST DR8, APOGEE DR16, GALAH DR2, and Gaia EDR3. In this sample, 52 are marginally hypervelocity star (HVS) candidates that have VGSR exceeding their local escape velocities within 2{sigma} confidence levels, 40 of which are discovered for the first time. All of the candidates are metal-poor, late-type halo stars, which are significantly different from the previously identified HVSs, which are largely massive early-type stars, discovered by extreme radial velocity. This finding suggests that our newly identified HVS candidates are ejected by different mechanisms from the previous population. To investigate their origins, for 547 extreme velocity stars with VGSR>~0.8Vesc, we reconstruct their backward-integrated trajectories in the Galactic potential. According to the orbital analysis, no candidates are found to be definitely ejected from the Galactic-center (GC), while eight metal-poor extreme velocity stars are found to have a closest distance to the GC within 1kpc. Intriguingly, 15 extreme velocity stars (including 2 HVS candidates) are found to have experienced close encounters with the Sagittarius dSph, suggesting that they originated from this dSph. This hypothesis is supported by an analysis of the [{alpha}/Fe]-[Fe/H] diagram. From a preliminary analysis of all of the 547 extreme velocity stars, we propose a general picture-star ejection from Galactic subsystems such as dwarf galaxies and globular clusters can be an important channel to produce extreme velocity stars or even HVSs, particularly the metal-poor late-type halo population.2023AJ....166...12Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/166/12CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/gcvs : General Catalogue of Variable Stars (Samus+, 2007-2017)II/282 : The SDSS Photometric Catalog, Release 6 (Adelman-McCarthy+, 2007)I/337 : Gaia DR1 (Gaia Collaboration, 2016)III/279 : RAVE 5th data release (Kunder+, 2017)I/345 : Gaia DR2 (Gaia Collaboration, 2018)II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)V/146 : LAMOST DR1 catalogs (Luo+, 2015)V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)J/AJ/128/1177 : Galactic stellar abundances (Venn+, 2004)J/ApJ/647/303 : Spectroscopic survey of hypervelocity stars (Brown+, 2006)J/ApJ/671/1708 : Hypervelocity stars. III (Brown+, 2007)J/AJ/136/2070 : SEGUE stellar parameter pipeline. III. (Allende Prieto+, 2008)J/AJ/136/2050 : SEGUE stellar parameter pipeline. II. (Lee+, 2008)J/AJ/136/614 : Arp 2 and Ter 8 red giants equivalent widths (Mottini+, 2008)J/ApJ/684/1143 : BHB candidates in the Milky Way (Xue+, 2008)J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)J/A+A/520/A95 : Abundances of red giants in M54 and Sgr dSph (Carretta+, 2010)J/ApJ/711/138 : Spectral analysis of HIP 60350 and 18 Peg (Irrgang+, 2010)J/AJ/141/90 : SEGUE stellar parameter pipeline. V. (Lee+, 2011)J/AJ/141/89 : SEGUE stellar parameter pipeline. IV. (Smolinski+, 2011)J/ApJ/751/55 : MMT hypervelocity star survey. II. (Brown+, 2012)J/AJ/144/4 : Properties dwarf galaxies in Local Group (McConnachie+, 2012)J/ApJ/765/154 : RR Lyrae stars in the Catalina Sky Survey (Drake+, 2013)J/ApJ/763/32 : Galactic halo RRab stars from CSS (Drake+, 2013)J/A+A/561/A87 : FLAMES observations of Terzan 8 (Carretta+, 2014)J/ApJS/213/9 : Catalina Surveys periodic variable stars (Drake+, 2014)J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/MNRAS/446/2251 : Southern Catalina Survey type-ab RR Lyrae (Torrealba+, 2015)J/MNRAS/469/3688 : CSS Periodic Variable Star Catalogue (Drake+, 2017)J/MNRAS/478/4513 : GALAH Survey DR2 (Buder+, 2018)J/AJ/156/90 : Catalog of APOGEE radial velocity std stars (Huang+, 2018)J/A+A/623/A110 : Gaia DR2. Variable stars in CMD (Gaia Collaboration+, 2019)J/MNRAS/482/4570 : Gaia DR2 white dwarf candidates (Gentile Fusillo+, 2019)J/MNRAS/490/157 : Fastest stars in the Galaxy with Gaia DR2 (Marchetti+, 2019)J/MNRAS/484/2832 : Proper motions Milky Way globular clusters (Vasiliev, 2019)J/ApJS/245/34 : Abundances for 6 million stars from LAMOST DR5 (Xiang+, 2019)J/MNRAS/504/356 : Updated parameters of 1743 open clusters (Dias+, 2021)J/ApJS/252/3 : High-velocity stars in Gal. halo from LAMOST &Gaia (Li+, 2021)J/A+A/653/A160 : Updated radial velocities from Gaia DR2 (Seabroke+, 2021)J/MNRAS/505/5978 : Gaia EDR3 view Galactic globular clusters (Vasiliev+, 2021)J/AJ/163/252 : Abundances for 15 extreme-velocity stars (Reggiani+, 2022)J/ApJS/259/60 : SEGUE-2 updated stellar parameter pipeline (Rockosi+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/166/12https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/166/12http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/166/12https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/166/12https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/166/12http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/166/12GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/166/12/table2 (The 52 hypervelocity star (HVS) candidates assuming different escape velocity curves)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/166/12/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/166/12/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/166/12/table2?GETtext/xml+votable180.050000true12.362361117.1289550.005555555555555556Cone search capability for table J/AJ/166/12/table3 (8 HiVel pass through the Galactic plane within 1kpc of the Galactic-center (GC))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/166/12/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/166/12/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/166/12/table3?GETtext/xml+votable180.050000true193.5312338916.571303060.005555555555555556Cone search capability for table J/AJ/166/12/table4 (Extreme velocity stars probably originating from the Sgr dSph)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/166/12/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/166/12/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/166/12/table4?GETtext/xml+votable180.050000true2.3758811140.684453890.005555555555555556Cone search capability for table J/AJ/166/12/table5 (Basic parameters for 88 HVSs or candidates (Table A1))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/166/12/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/166/12/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/166/12/table5?GETtext/xml+votable180.050000true12.362361117.1289550.0055555555555555566/321 399 622 1686 1874 2073 2722 4101 4195 4335 4501 4934 4972 5474 5706 5751 5791 5926 6344 6375 6548 6726 7465 7598 8207 8276 8427-8428 8444 8521 8552 8584 8749 8825 8969 8979 8985 9011 9098 9111 9455 9637 9973 9999 10248 10382 10548 10660 10686 10705 10752 10760 10781 10807 10895 11136 11278 11317 11331 12164 12555 12663-12664 12775 13415 13703 13946 15325 17787 17841 18166 18539 18659 19052 19111 19908 20410 25288 25290 26347 26472 26475 26957-26958 26994 27006 27034 27070 27074 27217 27421 27478 27690 27790 27901 27917 27957 27987 28012 28297 28413 28609 31475 32440 33944 37546 41248 41369 46278https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/166/12?format=asciiInfrareddefaultJ/AJ/166/12/table2The 52 hypervelocity star (HVS) candidates assuming different escape velocity curvesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource identifiermeta.idcharGaiaGaia DR3 identifiermeta.id;meta.mainRAJ2000[12/342] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-18/61] Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainpmRA[-74.5/76] Gaia DR3 proper motion along RA*cos(DE)mas/yrpos.pm;pos.eq.rafloate_pmRA[0.02/0.2] Uncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-129/13.3] Gaia DR3 proper motion along DEmas/yrpos.pm;pos.eq.decdoublee_pmDE[0.02/0.2] Uncertainty in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatVlos[-346/440] Line of sight velocitykm/sphys.veloc;pos.heliocentricdoublee_Vlos[1/20] Uncertainty in Vloskm/sstat.errorfloatDist[1.17/4.51] Distancekpcpos.distancefloate_Dist[0.06/1] Uncertainty in Diskpcstat.errorfloatVGSR[484/717] Galactic Standard of Rest velocitykm/sphys.veloc;pos.galacticfloate_VGSR[32.8/174] Uncertainty in VGSRkm/sstat.errorfloatPub-MW[0.13/0.92] MilkyWayPotential unbound probability (1)stat.fit.goodnessfloatPub-M18[0.12/0.91] Monari+, 2018A&A...616L...9M unbound probability (1)stat.fit.goodnessfloatPub-D19[0.34/0.96] Deason+, 2019MNRAS.485.3514D unbound probability (1)stat.fit.goodnessfloatPub-BMW[0.51/0.97] BovyMWPotential2014 unbound probability (1)stat.fit.goodnessfloatPub-W17[0.37/0.96] Williams+, 2017MNRAS.468.2359W unbound probability (1)stat.fit.goodnessfloatJ/AJ/166/12/table38 HiVel pass through the Galactic plane within 1kpc of the Galactic-center (GC)SimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource identifiermeta.idcharGaiaGaia DR3 identifiermeta.id;meta.mainRAJ2000Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainpmRAGaia DR3 proper motion along RA*cos(DE)mas/yrpos.pm;pos.eq.rafloate_pmRAUncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEGaia DR3 proper motion along DEmas/yrpos.pm;pos.eq.decfloate_pmDEUncertainty in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatVlosLine of sight velocitykm/sphys.veloc;pos.heliocentricdoublee_VlosUncertainty in Vloskm/sstat.errorfloatDistDistancekpcpos.distancefloate_DistUncertainty in Diskpcstat.errorfloatVGSRGalactic Standard of Rest velocitykm/sphys.veloc;pos.galacticfloate_VGSRUncertainty in VGSRkm/sstat.errorfloatCDisClosest distancekpcpos.distance;src.orbitalfloate_CDisUncertainty in CDiskpcstat.errorfloatBTimeBackward timeMyrtime.epochfloate_BTimeUncertainty in BTimeMyrstat.errorfloatJ/AJ/166/12/table4Extreme velocity stars probably originating from the Sgr dSphSimbadSimbad column added by the CDSmeta.ref.urlcharDistDistancekpcpos.distancefloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaGaia DR3 identifiermeta.id;meta.mainRAJ2000Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainpmRAGaia DR3 proper motion along RA*cos(DE)mas/yrpos.pm;pos.eq.rafloate_pmRAUncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEGaia DR3 proper motion along DEmas/yrpos.pm;pos.eq.decfloate_pmDEUncertainty in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatVlosLine of sight velocitykm/sphys.veloc;pos.heliocentricdoublee_VlosUncertainty in Vloskm/sstat.errorfloate_DistUncertainty in Diskpcstat.errorfloatVGSRGalactic Standard of Rest velocitykm/sphys.veloc;pos.galacticfloate_VGSRUncertainty in VGSRkm/sstat.errorfloatCDisClosest distancekpcpos.distance;src.orbitalfloate_CDisUncertainty in CDiskpcstat.errorfloatBTimeBackward timeMyrtime.epochfloate_BTimeUncertainty in BTimeMyrstat.errorfloatNameSource identifiermeta.idcharJ/AJ/166/12/table5Basic parameters for 88 HVSs or candidates (Table A1)SimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/88] Internal identifiermeta.idintHVSDisplay data for the 52 marginally hypervelocity star candidates (link to Table 2)meta.ref.urlintnullableNameSource identifier (1)meta.idcharprimaryGaiaGaia EDR3 identifier (2)meta.id;meta.mainRAJ2000[12/353] Right Ascension (J2000) (2)degpos.eq.ra;meta.mainDEJ2000[-75/75] Declination (J2000) (2)degpos.eq.dec;meta.mainpmRA[-81/99]? Gaia EDR3 proper motion along RA*cos(DE)mas/yrpos.pm;pos.eq.rafloatnullablee_pmRA[0.02/2]? Uncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE[-196/241]? Gaia EDR3 proper motion along DEmas/yrpos.pm;pos.eq.decdoublenullablee_pmDE[0.02/2]? Uncertainty in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatnullableVlos[-485/1200] Line of sight velocitykm/sphys.veloc;pos.heliocentricfloate_Vlos[1/80]? Uncertainty in Vloskm/sstat.errorfloatnullableDist[0.3/115] Distancekpcpos.distancefloate_Dist[0.01/22] Uncertainty in Diskpcstat.errorfloatTeff[4673/47200]? Effective temperatureKphys.temperature.effectiveintnullablee_Teff[13/1200]? Uncertainty in TeffKstat.error;phys.temperature.effectiveintnullablelogg[2.06/5.69]? log surface gravitylog(cm.s**-2)phys.gravityfloatnullablee_logg[0.02/0.9]? Uncertainty in log(g)log(cm.s**-2)stat.errorfloatnullable[Fe/H][-2.38/0.29]? Metallicitylog(Sun)phys.abund.Zfloatnullablee_[Fe/H][0/0.4]? Uncertainty in [Fe/H]log(Sun)stat.error;phys.abund.Fefloatnullable[a/Fe][-0.08/0.47]? log {alpha}/Fe abundance ratiolog(Sun)phys.abund;arith.ratiofloatnullablee_[a/Fe][0.01/0.8]? Uncertainty in [a/Fe]log(Sun)stat.error;phys.abundfloatnullableVrf[-638/1039] Galactic Rest-frame, line of sight velocitykm/sphys.velocfloate_Vrf[1/80]? Uncertainty in Vrfkm/sstat.errorfloatnullableVGSR[383/2511]? Galactic Standard of Rest velocitykm/sphys.veloc;pos.galacticfloatnullablee_VGSR[2/720]? Uncertainty in VGSRkm/sstat.errorfloatnullablef_Ref[ab] Flag on Ref (3)meta.codecharRefReference; ADS Bibcode if not this workmeta.ref;pos.framechar