J/ApJS/252/3ivo://CDS.VizieR/J/ApJS/252/3doi:10.26093/cds/vizier.22520003CDSLi Y.-B.Luo A.-L.Lu Y.-J.Zhang X.-S.Li J.Wang R.Zuo F.,Xiang M.Ting Y.-S.Marchetti T.Li S.Wang Y.-F.Zhang S.Hattori K.,Zhao Y.-H.Zhang H.-W.Zhao G.2024-10-07T20:12:43Z2022-03-03T12:45:18ZCDS support team

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

cds-question@unistra.frradial-velocityproper-motionsstellar-distancemetallicitymilky-way-galaxyhalo-starsinfrared-photometryvisible-astronomybroad-band-photometryIn this paper, we report 591 high-velocity star candidates (HiVelSCs) selected from over 10 million spectra of Data Release 7 (DR7) of the Large Sky Area Multi-object Fiber Spectroscopic Telescope and the second Gaia data release, with three-dimensional velocities in the Galactic rest frame larger than 445km/s. We show that at least 43 HiVelSCs are unbound to the Galaxy with escape probabilities larger than 50%, and this number decreases to eight if the possible parallax zero-point error is corrected. Most of these HiVelSCs are metal-poor and slightly {alpha}-enhanced inner halo stars. Only 14% of them have [Fe/H]>-1, which may be the metal-rich "in situ" stars in the halo formed in the initial collapse of the Milky Way or metal-rich stars formed in the disk or bulge but kinematically heated. The low ratio of 14% implies that the bulk of the stellar halo was formed from the accretion and tidal disruption of satellite galaxies. In addition, HiVelSCs on retrograde orbits have slightly lower metallicities on average compared with those on prograde orbits; meanwhile, metal-poor HiVelSCs with [Fe/H]{<}-1 have an even faster mean retrograde velocity compared with metal-rich HiVelSCs. To investigate the origins of HiVelSCs, we perform orbit integrations and divide them into four types, i.e., hypervelocity stars, hyper-runaway stars, runaway stars and fast halo stars.2021ApJS..252....3Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/252/3CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/254 : 2nd Cat. of RVel with Astrometric Data (Kharchenko+, 2007)I/345 : Gaia DR2 (Gaia Collaboration, 2018)V/153 : LAMOST DR4 catalogs (Luo+, 2018)V/164 : LAMOST DR5 catalogs (Luo+, 2019)J/AJ/103/514 : High-velocity stars toward South Galactic Cap (Reid+ 1992)J/BaltA/11/465 : Radial velocities of F5-M stars (Sperauskas+, 2002)J/A+A/410/527 : Abundances in the Galactic disk (Bensby+, 2003)J/ApJ/647/303 : Spectroscopic survey of hypervelocity stars (Brown+, 2006)J/A+A/445/939 : Metal-poor stars uvby-beta photometry. XI. (Schuster+, 2006)J/ApJ/684/1143 : BHB candidates in the Milky Way (Xue+, 2008)J/A+A/511/L10 : Abundances and space velocities of 94 stars (Nissen+, 2010)J/MNRAS/411/2596 : High Galactic latitude runaway stars (Silva+, 2011)J/ApJ/751/55 : MMT hypervelocity star survey. II. (Brown+, 2012)J/A+A/555/A12 : Foreground Galactic stars properties (Kordopatis+, 2013)J/A+A/568/A7 : Model SDSS colors for halo stars (Allende Prieto+, 2014)J/ApJ/813/26 : Runaway M dwarf candidates from SDSS-DR7 (Favia+, 2015)J/MNRAS/448/822 : LAMOST candidate members of star clusters (Xiang+, 2015)J/AJ/156/90 : New cat. of APOGEE RVel standard stars (Huang+, 2018)J/ApJS/245/34 : Abundances for 6 million stars from LAMOST DR5 (Xiang+, 2019)J/A+A/638/A122 : High-speed stars. Galactic hitchhikers (Caffau+, 2020)http://dr7.lamost.org/ : LAMOST DR7 home pagehttp://faststars.space/ : The open fast stars cataloghttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/252/3https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/252/3http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/252/3https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/252/3https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/252/3http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/252/3GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/252/3/hivelscs (The high-velocity star candidates (HiVelSCs) catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/252/3/hivelscs?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/252/3/hivelscs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/252/3/hivelscs?GETtext/xml+votable180.050000true240.337348241.166774120.0055555555555555566/74 128 132 468 622 708 729 792 1034 1267 2115 2184 2347 2625 2629 4187 4368 4464 4541 4603 4696 4767 5158 5450 5473 5484 5582 5593 5610 5612 5720 5753 5921 6264 6334 6371 6484 6868 6943 8207 8217 8262 8281 8292 8295 8308 8333 8367 8372 8391 8400 8417 8435-8436 8443 8454 8465 8470 8479 8499 8510 8514 8524 8528 8530 8538 8540 8559 8565 8568 8579 8586 8593 8631 8638 8658 8669 8698 8715 8732 8737 8744 8755 8757-8758 8761 8769 8793 8798 8800 8809 8822 8850 8854 8856 8863 8869 8872 8877 8879 8924 8939-8940 8953 8978 8982 8984 8986 9006 9009 9024 9038 9061 9077 9082 9086-9088 9098 9111 9119 9124 9126 9131 9135 9140-9141 9153 9156 9163-9164 9169 9179-9181 9186 9211 9222 9225 9251 9254 9270 9278 9290 9296 9305 9309 9331 9333 9337 9364 9368 9372 9376 9378 9387 9389 9396 9402 9414-9416 9420 9426 9429 9449 9454-9455 9467 9490 9492 9500-9502 9515 9522 9534 9547 9606-9607 9614 9619 9646 9654 9662 9667 9669 9682 9701 9706 9754 9771-9774 9784 9807 9809 9817-9818 9824 9828 9833 9861 9873 9881 9894 9908 9916 9927 9931 9936 9949 9954 9957 9974 9983 9991 10056 10082 10135 10145 10152 10188 10246 10259-10260 10267 10293 10300 10318 10323 10349 10362 10395 10403 10417 10433 10436 10439 10448-10449 10463 10483 10494 10497 10505 10507 10516 10543 10548 10552 10575 10577-10578 10593 10597 10601 10608 10654 10660 10680 10686 10695 10701 10705 10720 10760 10765 10781 10795 10807 10887 10919 10982 11017 11029 11058 11072 11089 11111-11112 11126 11149 11157 11274 11293 11305 11354 11407 11443-11444 11532 11993 12437 12545 12638 12686 13415 13432 13970 14523 14767 14779 14856 14868 14873 14882 14891 14923 14927 14936 14939 14967 14970 15033 15056 15075 15077 15100 15105 15119 15262 17787 18012 18100 18166 18227 18247 18352 18653 18682 18778 18797 18982 19009 19044 19053 19100 19177 19211 19282 19384 19860 19870 19908 20275 20277 20427 20452 20460 21831 22753 25575 25801 25901 25924 25936 25973 25982 26032 26063 26072 26170 26186 26189 26203 26277 26281 26286 26318 26347 26364 26418 26442 26468-26469 26484 26500 26547-26548 26578 26586 26620 26865 26893 26898 26910 26914 26937 26953 26972 27007-27008 27013 27029 27031 27116 27131 27175 27206 27234 27333 27337 27392 27419 27478 27500 27539 27581 27650 27654-27655 27692 27713 27722 27752 27784 27788 27790 27815 27829 27852 27917 27920 27936 27974 27983 27987 27990 28020 28040 28043 28068 28125 28127 28137 28188 28239 28245 28305-28306 28376 28397 28493 28522 28524 28528 28539 28651 28657 30033 30935 30961 30963 31032 31092 31128 31147 31164 31179 31209 31281 31305 31317 31319-31320 31328 31339 31342 31402 31405 31412 31415 31426 31456 31460 31467 31470 31477 31485 31487 31508 31511 31520 31536 31541 31544 31562 31576 31589 31592 31597-31598 31616 31620 31632-31633 31643 31650 31652 31669 31679 31690 31707 31713 31724 31779 31787 31979 32161-32162 32168 32193 32203 32234 32256 32273 32282 32285-32286 32292 32299-32300 32303-32304 32311 32339 32346 32348-32349 32353 32367 32379 32390 32401 32404 32406 32412 32433 32436 32451 32455 32465 32472 32479-32480 32498 32502 32511 32526 32540 32546 32572 32647-32648 32651 32654 32669 32688 32699 32736 32755 36862 44987 450361.9867573869263685e-19 4.621782916333392e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/252/3?format=asciiOpticalInfrareddefaultJ/ApJS/252/3/hivelscsThe high-velocity star candidates (HiVelSCs) catalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordinte_Vz[2/95] Lower uncertainty on Vzkm/sstat.errorintTeffDD[4075/8506]? Effective temperature estimated by the data-driven Payne method (see Xiang+ 2019ApJS..245...34X) from this workKphys.temperature.effective;meta.modelledintnullablee_TeffDD[16/511]? TeffDD uncertaintyKstat.errorintnullableloggDD[1.17/5.04]? Log of surface gravity estimated by the data-driven Payne method from this worklog(cm.s**-2)phys.gravity;meta.modelledfloatnullablee_loggDD[0.03/0.95]? LoggDD uncertaintylog(cm.s**-2)stat.errorfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.raindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decindexedSeq[1/591] High-velocity star numbermeta.id;meta.mainintGaiaGaia DR2 identifiermeta.idRA_ICRSGaia DR2 barycentric right ascension (ICRS) at Epoch=2015.5degpos.eq.ra;meta.maine_RA_ICRS[0.007/0.3] RAdeg uncertaintydegstat.error;pos.eq.rafloatDE_ICRS[-7/72.4] Gaia DR2 barycentric declination (ICRS) at Epoch=2015.5degpos.eq.dec;meta.maine_DE_ICRS[0.009/0.2] DEdeg uncertaintydegstat.error;pos.eq.decfloatS/N[7/610] r-band signal-to-noise ratiostat.snrintSpTSpectral type from LAMOSTsrc.spTypecharRV[-593/494] Radial velocity measured by the LASP from LAMOSTkm/sphys.veloc;pos.heliocentricinte_RV[3/35] RV uncertaintykm/sstat.errorintpmRA[-249/233] Gaia DR2 proper motion in RA (pmRA*cosDE)mas/yrpos.pm;pos.eq.radoublee_pmRA[0.016/0.5] pmRA uncertaintymas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-285.2/73.3] Gaia DR2 proper motion in DECmas/yrpos.pm;pos.eq.decdoublee_pmDE[0.018/0.4] pmDE uncertaintymas/yrstat.error;pos.pm;pos.eq.decfloatplx[0.06/7.8] Gaia DR2 parallaxmaspos.parallax.trigfloate_plx[0.012/0.3] plx uncertaintymasstat.error;pos.parallaxfloatGmag[10.63/17.57] Gaia DR2 G-band magnitudemagphot.mag;em.optfloatBPmag[9.29/20.3] Gaia DR2 BP-band magnitudemagphot.mag;em.opt.BfloatRPmag[6.75/19.43] Gaia DR2 RP-band magnitudemagphot.mag;em.opt.RfloatAstro[0/1] Reliable astrometric parameters? (1=high-quality; 476 occurrences -- see Section 2.4)meta.codeintRVc[-587/499] LASP radial velocity corrected the zero-point from LAMOSTkm/sphys.veloc;pos.heliocentricintDist[0.1/15.4] Heliocentric distance from this workkpcpos.distancefloate_Dist[0/2.4] Lower uncertainty on Distkpcstat.errorfloatE_Dist[0/3.3] Upper uncertainty on Distkpcstat.error;stat.maxfloatX[-15.5/-0.8] Cartesian Galactocentric X-coordinate from this workkpcpos.cartesian.x;pos.cartesian;pos.galactocentricfloate_X[0/1.8] Lower uncertainty on Xkpcstat.error;pos.cartesian.xfloatY[-3.5/13] Cartesian Galactocentric Y-coordinate from this workkpcpos.cartesian.y;pos.galactocentric;pos.cartesianfloate_Y[0/2] Lower uncertainty on Ykpcstat.error;pos.cartesian.yfloatE_Y[0/3] Upper uncertainty on Ykpcstat.error;stat.maxfloatZ[-5.3/11.2] Cartesian Galactocentric Z-coordinate from this workkpcpos.cartesian.z;pos.galactocentric;pos.cartesianfloate_Z[0/1.7] Lower uncertainty on Zkpcstat.error;src.redshiftfloatE_Z[0/3] Upper uncertainty on Zkpcstat.error;stat.maxfloatrGC[4/17] Galactocentric distance from this workkpcpos.distance;pos.galactocentricfloate_rGC[0/2] Lower uncertainty on rGCkpcstat.errorfloatE_rGC[0/2.8] Upper uncertainty on rGCkpcstat.error;stat.maxfloatVx[-612/706] Cartesian Galactocentric X-velocity from this workkm/sphys.veloc;pos.cartesian.xinte_Vx[1/142] Lower uncertainty on Vxkm/sstat.errorintE_Vx[1/179] Upper uncertainty on Vxkm/sstat.error;stat.maxintVy[-865/439] Cartesian Galactocentric Y-velocity from this workkm/sphys.veloc;pos.cartesian.yinte_Vy[3/237] Lower uncertainty on Vykm/sstat.errorintE_Vy[3/146] Upper uncertainty on Vykm/sstat.error;stat.maxintVz[-461/601] Cartesian Galactocentric Z-velocity from this workkm/sphys.veloc;pos.cartesian.zintE_Vz[3/139] Upper uncertainty on Vzkm/sstat.error;stat.maxintVgc[447/922] Cartesian Galactocentric total velocity from this workkm/sphys.veloc;pos.galactocentric;pos.cartesianinte_Vgc[5/169] Lower uncertainty on Vgckm/sstat.errorintE_Vgc[5/248] Upper uncertainty on Vgckm/sstat.error;stat.maxinte[0.89/1] Orbit eccentricity from this worksrc.orbital.eccentricitydoublee_e[0.0003/0.3] Lower uncertainty on estat.errordoubleE_e[9e-05/0.08] Upper uncertainty on estat.error;stat.maxdoubleZmax[12/5447] Orbit maximum height above the Galactic disk from this workkpcpos.cartesian.z;pos.galactic;stat.maxfloatVescG[547/642] Escape velocity estimated by the potential model in G05 (1)km/sphys.veloc.escape;meta.modelledinte_Zmax[3/2465] Lower uncertainty on Zmaxkpcstat.errorfloatE_Zmax[2/2516] Upper uncertainty on Zmaxkpcstat.error;stat.maxfloatRmin[0.1/540.3]? Minimum crossing radius from this workkpcphys.size.radius;stat.minfloatnullablee_Rmin[0/535]? Lower uncertainty on Rminkpcstat.errorfloatnullableE_Rmin[0/836]? Upper uncertainty on Rminkpcstat.error;stat.maxfloatnullableE-phi[-0.0005/0.004] The difference between orbit energy E and potential energy at infinitykpc**2.Myr**-2phys.energy;arith.difffloate_E-phi[0/0.002] Lower uncertainty on E-phikpc**2.Myr**-2stat.errorfloatE_E-phi[0/0.003] Upper uncertainty on E-phikpc**2.Myr**-2stat.error;stat.maxfloatVescW[552/670] Escape velocity estimated by the potential model in W19 (1)km/sphys.veloc.escape;meta.modelledintVescKe[525/646] Escape velocity estimated by the potential model in K14 (1)km/sphys.veloc.escape;meta.modelledintVescKo[498/614] Escape velocity estimated by the potential model in K10 (1)km/sphys.veloc.escape;meta.modelledintVescP[472/582] Escape velocity estimated by the potential model in P90 (1)km/sphys.veloc.escape;meta.modelledintVescM[444/576] Escape velocity estimated by the potential model in B15 (1)km/sphys.veloc.escape;meta.modelledintVescX[434/538] Escape velocity estimated by the potential model in X08 (1)km/sphys.veloc.escape;meta.modelledintPgc[0/0.991] Probability of ejecting from the GCstat.fit.goodnessfloatPmw[0/1] Probability of ejecting from the Galactic diskstat.fit.goodnessfloatPubW[0/1] Unbound probability in the potential model in W19 (1)stat.fit.goodnessfloatPubG[0/1] Unbound probability in the potential model in G05 (1)stat.fit.goodnessfloatPubKe[0/1] Unbound probability in the potential model in K14 (1)stat.fit.goodnessfloatPubKo[0/1] Unbound probability in the potential model in K10 (1)stat.fit.goodnessfloatPubP[0/1] Unbound probability in the potential model in P90 (1)stat.fit.goodnessfloatPubM[0/1] Unbound probability in the potential model in B15 (1)stat.fit.goodnessfloatPubX[0/1] Unbound probability under the potential model in X08 (1)stat.fit.goodnessfloatTeff[3784/13760] Effective temperature estimated by the LASP from this workKphys.temperature.effective;meta.modelledinte_Teff[10/794] Teff uncertaintyKstat.error;phys.temperature.effectiveintlogg[0.75/5.49] Log of surface gravity estimated by the LASP from this worklog(cm.s**-2)phys.gravity;meta.modelledfloate_logg[0.01/1.03] Logg uncertaintylog(cm.s**-2)stat.errorfloat[Fe/H][-2.5/1] Metallicity estimated by the LASP from this worklog(Sun)phys.abund.Fefloate_[Fe/H][0/0.61] [Fe/H] uncertaintylog(Sun)stat.error;phys.abund.Fefloat[Fe/H]DD[-3.5/0.3]? Metallicity estimated by the data-driven Payne method from this workphys.abund.Z;meta.modelledfloatnullablee_[Fe/H]DD[0.02/0.8]? [Fe/H]DD uncertaintystat.error;phys.abund.Fefloatnullablea/Fe[-0.29/0.65] {alpha} abundance estimated by the data-driven Payne methodphys.abundfloate_a/Fe[0.01/0.42] a/Fe uncertaintystat.error;phys.abundfloatC[0/1] HiVelSCs satisfy all more conservative criteria in Section 5.2 (1=conservative; 92 occurrences)meta.codeintLAMOSTDisplay data from LAMOST -DR4 (V/153) and -DR5 (V/164) within 1"meta.ref.urlintnullablespIDLAMOST DR7 identifiermeta.id;meta.filecharClassOrigin classification (2)meta.code.classcharE_X[0/1.9] Upper uncertainty on Xkpcstat.error;stat.maxfloat