J/ApJ/887/267ivo://CDS.VizieR/J/ApJ/887/267doi:10.26093/cds/vizier.18870267CDSMurray C.E.Peek J.E.G.Di Teodoro E.M.McClure-Griffiths N.M.,Dickey J.M.Denes H.2022-06-13T12:18:47Z2021-06-24T14:45:57ZCDS support team

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

cds-question@unistra.frob-starsradial-velocityh-i-line-emissionproper-motionsmagellanic-cloudsstellar-spectral-typesWe investigate the kinematics of neutral gas in the Small Magellanic Cloud (SMC) and test the hypothesis that it is rotating in a disk. To trace the 3D motions of the neutral gas distribution, we identify a sample of young, massive stars embedded within it. These are stars with radial velocity measurements from spectroscopic surveys and proper motion measurements from Gaia, whose radial velocities match with dominant HI components. We compare the observed radial and tangential velocities of these stars with predictions from the state-of-the-art rotating disk model based on high-resolution 21cm observations of the SMC from the Australian Square Kilometer Array Pathfinder telescope. We find that the observed kinematics of gas-tracing stars are inconsistent with disk rotation. We conclude that the kinematics of gas in the SMC are more complex than can be inferred from the integrated radial velocity field. As a result of violent tidal interactions with the Large Magellanic Cloud, nonrotational motions are prevalent throughout the SMC, and it is likely composed of distinct substructures overlapping along the line of sight.2019ApJ...887..267Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/887/267CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/236 : UBVR CCD survey of the Magellanic clouds (Massey+, 2002)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/MNRAS/289/225 : SMC HI shells velocities (Staveley-Smith+ 1997)J/AJ/131/2514 : Radial velocities of red giants in the SMC (Harris+, 2006)J/MNRAS/386/826 : Radial velocities of SMC massive stars (Evans+, 2008)J/ApJ/745/173 : UV absorption sight lines of LMC and SMC (Welty+, 2012)J/MNRAS/442/1663 : Velocities of red giants in the SMC (Dobbie+, 2014)J/A+A/594/A116 : HI4PI spectra and column density maps (HI4PI team+, 2016)J/ApJ/817/113 : RIOTS4: spec. survey of SMC field OB stars (Lamb+, 2016)J/ApJ/816/49 : Spitzer/IRAC observations of SMC Cepheids (Scowcroft+, 2016)J/MNRAS/472/808 : YJKs light curves of SMC Classical Cepheids (Ripepi+, 2017)J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)J/ApJ/867/L8 : Gaia kinematic data of SMC OB stars (Oey+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/887/267https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/887/267http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/887/267https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/887/267https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/887/267http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/887/267GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/887/267/table1 (Parameters for the 143 stars used in the kinematic comparison)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/887/267/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/887/267/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/887/267/table1?GETtext/xml+votable180.050000true7.798-73.9930.0055555555555555565/8323-8324 6/33291 33300 33302 33304-33306 33316-33317 33328https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/887/267?format=asciiRadiodefaultJ/ApJ/887/267/table1Parameters for the 143 stars used in the kinematic comparisonrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[7.79/24.4] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-74.3/-72.1] Declination (J2000)degpos.eq.dec;meta.mainRVel[105/198] Stellar radial velocitykm/sphys.veloc;pos.heliocentricfloate_RVel[4/16] Uncertainty in RVelkm/sstat.error;spect.dopplerVelocfloatSpTypeSpectral typesrc.spTypecharr_RVel[1/2] Reference code for RVel (1)meta.ref;pos.frameintpmW[-1.5/-0.4] Proper motion in the West direction (2)mas/yrpos.pm;pos.eq.rafloatpmN[-2.2/-0.7] Proper motion in the North direction (2)mas/yrpos.pm;pos.eq.decfloate_pmW[0.047/0.2] Uncertainty in pmWmas/yrstat.errorfloate_pmN[0.039/0.2] Uncertainty in pmNmas/yrstat.errorfloatRVCatDisplay data from RIOTS4 (Lamb+, 2016, J/ApJ/817/113) and Evans+, 2008, J/MNRAS/386/826 within 2"meta.ref.urlintnullableGaiaDisplay Gaia data from 2018, J/A+A/616/A12 and DR2 (I/345) within 2"meta.ref.urlintnullable