J/ApJ/813/89ivo://CDS.VizieR/J/ApJ/813/89doi:10.26093/cds/vizier.18130089CDSKing III C.Brown W.R.Geller M.J.Kenyon S.J.2017-01-23T22:00:00Z2016-03-18T12:52:30ZCDS support team

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

cds-question@unistra.frradial-velocityf-starshalo-starsvisible-astronomysloan-photometrymilky-way-galaxyWe measure the three components of velocity dispersion, {sigma}_R_, {sigma}_{theta}_, {sigma}_{phi}_, for stars within 6<R<30kpc of the Milky Way using a new radial velocity sample from the MMT telescope. We combine our measurements with previously published data so that we can more finely sample the stellar halo. We use a maximum likelihood statistical method for estimating mean velocities, dispersions, and covariances assuming only that velocities are normally distributed. The alignment of the velocity ellipsoid is consistent with a spherically symmetric gravitational potential. From the spherical Jeans equation, the mass of the Milky Way is M(R<=12kpc)=1.3x10^11^M_{sun}_ with an uncertainty of 40%. We also find a region of discontinuity, 15<~R<~25kpc, where the estimated velocity dispersions and anisotropies diverge from their anticipated values, confirming the break observed by others. We argue that this break in anisotropy is physically explained by coherent stellar velocity structure in the halo, such as the Sgr stream. To significantly improve our understanding of halo kinematics will require combining radial velocities with future Gaia proper motions.2015ApJ...813...89Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/813/89CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/568/A7 : Model SDSS colors for halo stars (Allende Prieto+, 2014)J/AJ/146/21 : LINEAR. II. Catalog of RR Lyrae stars (Sesar+, 2013)J/ApJ/751/55 : MMT hypervelocity star survey. II. (Brown+, 2012)J/ApJ/738/79 : SDSS-DR8 BHB stars in the Milky Way's halo (Xue+, 2011)J/ApJ/731/4 : Galactic halo as seen by the CFHTLS (Sesar+, 2011)J/AJ/139/59 : Milky Way halo velocity dispersion profile (Brown+, 2010)J/MNRAS/398/1757 : RR Lyraes in SDSS stripe 82 (Watkins+, 2009)J/ApJ/703/2177 : Metal-poor MS turnoff stars summary (Schlaufman+, 2009)J/ApJ/684/1143 : BHB candidates in the Milky Way (Xue+, 2008)J/AJ/136/2070 : SEGUE stellar parameter pipeline. III. (Allende Prieto+, 2008)J/AJ/135/564 : Photometry and spectroscopy of BHB candidates (Brown+, 2008)J/AJ/130/1097 : Century Survey Galactic Halo Project BHB stars (Brown+, 2005)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/813/89https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/813/89http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/813/89https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/813/89https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/813/89http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/813/89GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/813/89/table2 (Hectospec F stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/813/89/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/813/89/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/813/89/table2?GETtext/xml+votable180.050000true9.8768833325.247944440.0055555555555555565/1387 1435 1436 1447 1451 1452 1472 1519 1627 1628 1633 1648 1792 2487 2492 2538 2628 2672 2827 2848 2850 2856 4437 4454 4502 4505 4697 4758 6485 6814 7846 7850 6/708 4638 4639 4660 4669 4670 4671 4720 4722 4723 4745 4747 4748 4750 4943 4965 4967 5036 5038 5048 5050 5301 5303 5344 5346 5488 5489 5490 5547 5568 5569 5570 5701 5712 5719 5723 5724 5725 5726 5735 5739 5748 5752 5783 5787 5799 5803 5812 5824 5825 5826 5892 5896 6069 6070 6071 6073 6114 6120 6212 6213 6337 6339 6340 6393 6395 6397 6487 6491 6492 6493 6494 6503 6507 6516 6518 6520 6521 6524 6551 6556 6557 6558 6596 6600 6602 6603 6606 6741 6743 6912 7176 8139 8142 8161 8164 8192 8966 8967 8969 8971 8972 8973 9146 9147 9363 9366 9372 9430 9436 9476 9477 9578 9587 9590 9593 9595 9596 9643 9664 9821 9823 9837 9838 9841 9844 9848 9877 9879 9883 9885 9886 9887 9893 9895 9898 9899 9900 9901 9903 9904 9905 9908 9912 9921 9922 9923 9924 9947 9963 9964 9966 9967 9972 9986 9987 9992 10147 10150 10156 10157 10158 10518 10521 10524 10582 10585 10587 10588 10590 10591 10601 10603 10604 10609 10610 10611 10612 10650 10651 10652 10655 10661 10669 10671 10672 10675 10680 10696 10741 10743 10749 10839 10844 10845 10846 10855 10860 10861 10866 10933 10935 10941 10955 10958 10959 10976 10977 10978 10980 10981 11010 11011 11012 11017 11264 11266 11267 11268 11291 11294 11295 11307 11312 11313 11316 11317 11320 11321 11322 11329 11330 11331 11332 11333 11336 11337 11396 11397 11398 11428 11430 11432 11433 11434 11520 11521 11524 12653 17766 17767 17772 17773 17811 17814 17820 17999 18003 18012 18032 18033 18785 18786 18787 18793 18796 18797 19026 19027 19030 19036 19037 19038 19096 19097 19099 19101 19103 19144 19373 19384 19386 19501 19941 19943 19954 25939 25945 25948 27239 27245 27246 27247 27333 27344 27345 27743 27764 27765 27767 27914 27936 27938 31374 31375 31395 31397 31398 31404 31408 32686 36845 36846 36847 45055https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/813/89?format=asciiOpticaldefaultJ/ApJ/813/89/table2Hectospec F starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainHRV[-515/448] Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRV[1/54] Uncertainty in HRVkm/sstat.errorfloatrmag0[14.9/21.2] SDSS DR10 de-reddened r-band magnitudemagphot.mag;em.opt.Rfloate_rmag0[0.008/4] Uncertainty in rmagmagstat.error;phot.magfloatrMag[0.9/7] Absolute r band magnitude estimatemagphys.magAbsfloatR[5.5/68.2] Galactocentric radial distance (1)kpcpos.distance;pos.galactocentricfloatZ[-51.1/46.5] Galactocentric vertical distance (1)kpcpos.distance;pos.cartesian.z;pos.galactocentricfloatDR9Display the SDSS-DR9 photometric data within 2"meta.ref.urlcharSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlchar