J/ApJ/962/174ivo://CDS.VizieR/J/ApJ/962/174CDSWei L.Theissen C.A.Konopacky Q.M.Lu J.R.Hsu C.-C.Kim D.2026-06-25T07:27:44Z2026-06-25T08:10:16ZCDS support team

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

cds-question@unistra.fropen-star-clustersstar-forming-regionsradial-velocityeffective-temperatureproper-motionsstellar-massesinfrared-astronomyspectroscopyvisible-astronomyWe present the kinematic analysis of 246 stars within 4' from the center of Orion Nebula Cluster (ONC), the closest massive star cluster with active star formation across the full mass range, which provides valuable insights in the formation and evolution of star cluster on an individual-star basis. High-precision radial velocities and surface temperatures are retrieved from spectra acquired by the NIRSPEC instrument used with adaptive optics (NIRSPAO) on the Keck II 10m telescope. A 3D kinematic map is then constructed by combining with the proper motions previously measured by the Hubble Space Telescope Advanced Camera for Surveys/WFPC2/WFC3IR and Keck II NIRC2. The measured root-mean-squared velocity dispersion is 2.26+/-0.08km/s, significantly higher than the virial equilibrium's requirement of 1.73km/s, suggesting that the ONC core is supervirial, consistent with previous findings. Energy equipartition is not detected in the cluster. Most notably, the velocity of each star relative to its neighbors is found to be negatively correlated with stellar mass. Low-mass stars moving faster than their surrounding stars in a supervirial cluster suggests that the initial masses of forming stars may be related to their initial kinematic states. Additionally, a clockwise rotation preference is detected. A weak sign of inverse mass segregation is also identified among stars excluding the Trapezium stars, although it could be a sample bias. Finally, this study reports the discovery of four new candidate spectroscopic binary systems.2024ApJ...962..174Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/962/174CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)J/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)J/ApJ/676/1109 : Velocities of stars in Orion Nebula Cluster (Furesz+, 2008)J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)J/ApJ/697/1103 : Kinematics of Orion Nebula Cluster (Tobin+, 2009)J/ApJ/723/684 : NIRSPEC ultracool dwarf radial velocity survey (Blake+, 2010)J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)J/ApJ/753/149 : YSOVAR: 6 EBs in Orion (Morales-Calderon+, 2012)J/ApJS/207/10 : HST Treasury Program on the ONC (Robberto+, 2013)J/A+A/564/A125 : AGN Torus model comparison of AGN in the CDFS (Buchner+, 2014)J/AJ/147/87 : From binaries to multiples. II. Stat. (Tokovinin, 2014)J/ApJ/799/136 : IN-SYNC. II. Candidate young stars in NGC 1333 (Foster+, 2015)J/ApJ/818/59 : IN-SYNC. IV. YSOs in Orion A (Da Rio+, 2016)J/ApJ/821/8 : Spectroscopic binary pop. of ONC and NGC2264 (Kounkel+, 2016)J/A+A/600/A141 : Orion A integral shaped filament image (Kainulainen+, 2017)J/AJ/156/84 : APOGEE-2 survey of Orion Complex. II. (Kounkel+, 2018)J/ApJ/871/46 : Hectoschelle sp. of 2MASS stars in Cep OB3b (Karnath+, 2019)J/AJ/157/109 : Stellar proper motions in Orion Nebula Cluster (Kim+, 2019)J/AJ/157/196 : Close companions around young stars (Kounkel+, 2019)J/AJ/157/216 : Stellar mult. rate of M dwarfs within 25 pc (Winters+, 2019)J/ApJS/257/45 : BDKP. V. Radial & rot. vel. of M, L, T dwarfs (Hsu+, 2021)J/ApJ/926/141 : 3-D kinematics of Orion Nebula Cluster (Theissen+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/962/174https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/962/174http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/962/174https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/962/174https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/962/174http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/962/174GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/962/174/table3 (NIRSPAO forward-modeling results)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/962/174/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/962/174/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/962/174/table3?GETtext/xml+votable180.050000true83.817875-5.387943890.005555555555555556Cone search capability for table J/ApJ/962/174/table1 (Log of NIRSPEC with AO system (NIRSPAO) observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/962/174/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/962/174/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/962/174/table1?GETtext/xml+votable180.050000true83.8178664-5.38793080.0055555555555555566/21439https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/962/174?format=asciiOpticalInfrareddefaultJ/ApJ/962/174/table3NIRSPAO forward-modeling resultsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpmRA-DR3[-1.9/2.9]? Proper motion in right ascension, Gaia DR3 (I/355)mas/yrpos.pm;pos.eq.rafloatnullablee_pmRA-DR3[0.014/0.4]? Uncertainty of pmRA-DR3mas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE-DR3[-2.5/2.8]? Proper motion in declination, Gaia DR3 (I/355)mas/yrpos.pm;pos.eq.decfloatnullableSimbadNameSimbad column added by the CDSmeta.idcharnullableNobsDisplay the NIRSPAO observations for this source (link to Table 1)meta.numberintnullable[HC2000]? Identifier in Hillenbrand+ 2000, J/ApJ/540/236meta.id;meta.mainintnullable[KLK2019]? Identifier in Kim+ 2019, J/AJ/157/109meta.id.crossintnullableAPOGEE? Identifier in APOGEE-2 DR16 (III/284)meta.id.crosscharGaiaDR3? Identifier in Gaia DR3 (I/355)meta.id.crosscharRAJ2000[83.75/83.9] Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-5.5/-5.3] Declination (J2000)degpos.eq.dec;meta.mainTeff[2666/6998] Effective temperature adopted for analysis in this study (1)Kphys.temperature.effectivefloate_Teff[1.6/285] Uncertainty of Teff (1)Kstat.error;phys.temperature.effectivefloatRVel[-3.2/50] Radial velocity adopted for analysis in this study (1)km.s**-1spect.dopplerVelocfloate_RVel[0.12/5] Uncertainty of RVel (1)km.s**-1stat.error;spect.dopplerVelocfloatpmRA[-2.5/3]? Proper motion in right ascension adopted for analysis in this study (2)mas/yrpos.pm;pos.eq.rafloatnullablee_pmRA[0.01/2.2]? Uncertainty of pmRA (2)mas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE[-3.9/3.3]? Proper motion in declination adopted for analysis in this study (2)mas/yrpos.pm;pos.eq.decfloatnullableT22Display the data from Theissen+ 2022, J/ApJ/926/141meta.ref.urlintnullablee_pmDE[0.01/3]? Uncertainty of pmDE (2)mas/yrstat.error;pos.pm;pos.eq.decfloatnullableTeff-AO[2666/6729]? Effective temperature derived from NIRSPAO observation in this studyKphys.temperature.effectivefloatnullablee_Teff-AO[10/285]? Uncertainty of Teff-NIRSPAOKstat.error;phys.temperature.effectivefloatnullableRVel-AO[-3.2/50]? Radial velocity derived from NIRSPAO observation in this studykm.s**-1spect.dopplerVelocfloatnullablee_RVel-AO[0.12/5]? Uncertainty of RVel-NIRSPAOkm.s**-1stat.error;spect.dopplerVelocfloatnullablevsini-AO[0.5/99.7]? Projected rotational velocity derived from NIRSPAO observation in this studykm.s**-1phys.veloc.rotatfloatnullablee_vsini-AO[0.13/11]? Uncertainty of vsini-NIRSPAOkm.s**-1stat.error;phys.veloc.rotatfloatnullableSNR-O32[1.9/127.2]? Signal-to-noise ratio, order 32stat.snrfloatnullableSNR-O33[4.7/134.4]? Signal-to-noise ratio, order 33stat.snrfloatnullableSNR-O35[63.83]? Signal-to-noise ratio, order 35stat.snrfloatnullableVeil-O32[0/7.35]? Veiling parameter, order 32 (3)phys.absorptionfloatnullableVeil-O33[0/6.4]? Veiling parameter, order 33 (3)phys.absorptionfloatnullableVeil-O35[5.48]? Veiling parameter, order 35 (3)phys.absorptionfloatnullableTeff-T22[2722/6998]? Effective temperature, Theissen+ (2022, J/ApJ/926/141)Kphys.temperaturefloatnullablee_Teff-T22[1.6/253]? Uncertainty on Teff-T22Kstat.error;phys.temperature.effectivefloatnullableRVel-T22[19/47.7]? Radial velocity, Theissen+ (2022, J/ApJ/926/141)km.s**-1spect.dopplerVelocfloatnullablee_RVel-T22[0.1/3.6]? Uncertainty on Rvel-T22km.s**-1stat.error;spect.dopplerVelocfloatnullablevsini-T22[2.2/299.5]? Projected rotational velocity, Theissen+ (2022, J/ApJ/926/141)km.s**-1phys.veloc.rotatfloatnullablee_vsini-T22[0.04/11]? Uncertainty on vsini-T22km.s**-1stat.error;phys.veloc.rotatfloatnullablepmRA-K19[-2.5/3]? Proper motion in right ascension, Kim+ (2019 J/AJ/157/109)mas/yrpos.pm;pos.eq.rafloatnullablee_pmRA-K19[0.01/2.2]? Uncertainty of pmRA-K19mas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE-K19[-3.85/3.21]? Proper motion in declination, Kim+ (2019 J/AJ/157/109)mas/yrpos.pm;pos.eq.decfloatnullablee_pmDE-K19[0.01/2.8]? Uncertainty of pmDE-K19mas/yrstat.error;pos.pm;pos.eq.decfloatnullablee_pmDE-DR3[0.012/0.3]? Uncertainty of pmDE-DR3mas/yrstat.error;pos.pm;pos.eq.decfloatnullableMs-MIST[0.1/2.9]? Stellar mass based on MIST model (2016ApJS..222....8D, 2016ApJ...823..102C)solMassphys.massfloatnullablee_Ms-MIST[0/0.7]? Uncertainty of Ms-MISTsolMassstat.error;phys.massfloatnullableMs-BHAC15[0.02/1.4]? Stellar mass based on BHAC15 model (2015A&A...577A..42B)solMassphys.massfloatnullablee_Ms-BHAC15[0/0.21]? Uncertainty of Ms-BHAC15solMassstat.error;phys.massfloatnullableMs-Feiden[0.1/3]? Stellar mass based on Feiden model (2016A&A...593A..99F)solMassphys.massfloatnullablee_Ms-Feiden[0/0.7]? Uncertainty of Ms-FeidensolMassstat.error;phys.massfloatnullableMs-Palla[0.1/2.5]? Stellar mass based on Palla model (1999ApJ...525..772P)solMassphys.massfloatnullablee_Ms-Palla[0/0.51]? Uncertainty of Ms-PallasolMassstat.error;phys.massfloatnullablem_[HC2000]Component on [HC2000]meta.code.multipcharJ/ApJ/962/174/table1Log of NIRSPEC with AO system (NIRSPAO) observationsSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintResultsDisplay the NIRSPAO forward-modeling results for this source (link to Table 3)meta.numberintnullable[HC2000]HC2000 identifier in Hillenbrand+ 2000, J/ApJ/540/236meta.id;meta.mainintm_[HC2000]Component letter on [HC2000]meta.code.multipcharDateDate of observation (UT)time.epochnullableNfr[2/6] Number of ABBA framesmeta.numberintExp[60/1200] Exposure time per framesobs.exposure;pos.frameintT22Display the data from Theissen+ 2022, J/ApJ/926/141meta.ref.urlintnullable_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.main