J/ApJ/921/32ivo://CDS.VizieR/J/ApJ/921/32doi:10.26093/cds/vizier.19210032CDSJi A.P.Koposov S.E.Li T.S.Erkal D.Pace A.B.Simon J.D.,Belokurov V.Cullinane L.R.Da Costa G.S.Kuehn K.Lewis G.F.,Mackey D.Shipp N.Simpson J.D.Zucker D.B.Hansen T.T.,Bland-Hawthorn J.The S5 Collaboration.2024-02-06T12:58:55Z2023-03-22T08:06:18ZCDS support team

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

cds-question@unistra.frgalaxiesspectroscopyvisible-astronomyradial-velocityproper-motionsmetallicityphotometrysurveysdwarf-galaxiesWe present new spectroscopic observations of the diffuse Milky Way satellite galaxies Antlia 2 and Crater 2, taken as part of the Southern Stellar Stream Spectroscopic Survey (S5). The new observations approximately double the number of confirmed member stars in each galaxy and more than double the spatial extent of spectroscopic observations in Antlia 2. A full kinematic analysis, including Gaia EDR3 proper motions, detects a clear velocity gradient in Antlia 2 and a tentative velocity gradient in Crater 2. The velocity gradient magnitudes and directions are consistent with particle stream simulations of tidal disruption. Furthermore, the orbit and kinematics of Antlia 2 require a model that includes the reflex motion of the Milky Way induced by the Large Magellanic Cloud. We also find that Antlia 2's metallicity was previously overestimated, so it lies on the empirical luminosity-metallicity relation and is likely only now experiencing substantial stellar mass loss. Current dynamical models of Antlia 2 require it to have lost over 90% of its stars to tides, in tension with the low stellar mass loss implied by the updated metallicity. Overall, the new kinematic measurements support a tidal disruption scenario for the origin of these large and extended dwarf spheroidal galaxies.2021ApJ...921...32Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/921/32CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/350 : Gaia EDR3 (Gaia Collaboration, 2020)III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)J/A+A/538/A100 : Abundances red giants in Carina dSph (Lemasle+, 2012)J/MNRAS/434/1681 : Extremely metal-poor stars CaII triplet (Carrera+, 2013)J/ApJ/779/102 : Metallicities of RGB stars in dwarf gal. (Kirby+, 2013)J/ApJ/833/167 : PAndAS view of Andromeda satellites. II. (Martin+, 2016)J/ApJ/819/53 : Magellan/M2FS sp. of Tucana 2 & Grus 1 (Walker+, 2016)J/A+A/616/A10 : 46 open clusters GaiaDR2 HR diag. (Gaia Col., 2018)J/ApJ/857/104 : Low surface brightness gal. from HSC-SSP (Greco+, 2018)J/AJ/156/257 : Sp. of RGB stars in Draco & Ursa Minor (Spencer+, 2018)J/A+A/625/A76 : NGC1052-DF2 VLT/MUSE datacubes (Emsellem+, 2019)J/ApJ/883/11 : Magellan/IMACS sp. of Crater II & Hercules (Fu+, 2019)J/MNRAS/490/3508 : The Southern Stellar Stream Sp. Survey (S^5^) (Li+, 2019)J/ApJ/875/77 : PMs of MW satellites with Gaia & DES (Pace+, 2019)J/ApJ/885/3 : Membership in 12 stellar streams from DES (Shipp+, 2019)J/MNRAS/488/2743 : Giant Gal. dwarf satellite in Gaia DR2 (Torrealba+, 2019)J/MNRAS/491/3496 : Andromeda XIX member stars (Collins+, 2020)J/AJ/160/181 : Abundances in red giants with Magellan (Ji+, 2020)J/AJ/159/46 : Abundances of 416 stars in 5 dSphs of M31 (Kirby+, 2020)J/A+A/640/A106 : MUSE MATLAS-2019 spectral datacube (Mueller+, 2020)J/other/Nat/583.768 : 2050 red giants CaII EWs (Wan+, 2020)J/ApJ/906/96 : Dwarfs gal. in DC Justice League Simu. (Applebaum+, 2021)J/MNRAS/506/150 : The GALAH+ Survey DR3 (Buder+, 2021)J/ApJ/911/149 : Sp. obs. in ATLAS and Aliqa Uma streams (Li+, 2021)J/A+A/649/A3 : Gaia EDR3 photometric passbands (Riello+, 2021)J/ApJS/252/18 : LSB galaxies from DES Y3 (Tanoglidis+, 2021)http://s5collab.github.io/ : S^5^ home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/921/32https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/921/32http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/921/32https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/921/32https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/921/32http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/921/32GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/921/32/table4 (Antlia 2 data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/921/32/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/921/32/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/921/32/table4?GETtext/xml+votable180.050000true142.53357-37.914390.005555555555555556Cone search capability for table J/ApJ/921/32/table5 (Crater 2 data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/921/32/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/921/32/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/921/32/table5?GETtext/xml+votable180.050000true177.59227-19.35520.0055555555555555565/6295 9656 6/25174-25175 25177 38583 38601-38603 38606 38628-38630 38632-38633 38635-38636 386381.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/921/32?format=asciiOpticaldefaultJ/ApJ/921/32/table4Antlia 2 dataBin[YN] Binary Flagmeta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaGaia EDR3 Source IDmeta.id;meta.mainRA_ICRS[141.9/146] Right Ascension (ICRS) at Epoch=2015.5degpos.eq.ra;meta.mainDE_ICRS[-38.8/-34.5] Declination (ICRS) at Epoch=2015.5degpos.eq.dec;meta.mainGmag[16.97/20.34] Gaia EDR3 G-band magnitudemagphot.mag;em.optfloatpmRA[-3.9/1.1] Gaia EDR3 Proper motion in Right Ascensionmas/yrpos.pm;pos.eq.rafloatpmDE[-4.9/2.2] Gaia EDR3 Proper motion in Declinationmas/yrpos.pm;pos.eq.decfloatSimbadSimbad 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.decindexedHRV[-105/420] Heliocentric Radial Velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRV[0.7/10] Uncertainty in HRVkm/sstat.errorfloat[Fe/H]1[-3.5/1] Metallicity, S5 data release (DR2.2)phys.abund.Zfloate_[Fe/H]1[0.01/99] Uncertainty in [Fe/H]1stat.error;phys.abund.Fefloat[Fe/H]2[-3.5/1.8] Metallicity, higher-resolution red calcium triplet (CaT)phys.abund.Zfloate_[Fe/H]2[0.1/5] Uncertainty in [Fe/H]2stat.error;phys.abund.FefloatMm[0/1] Membership probabilitystat.probability;meta.code.memberfloatS/N[4/32.2] Spectra Signal to Noisestat.snrfloatJ/ApJ/921/32/table5Crater 2 dataSimbadSimbad 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.decindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaGaia EDR3 Source IDmeta.id;meta.mainRA_ICRS[176.5/178.4] Right Ascension (ICRS) at Epoch=2015.5degpos.eq.ra;meta.mainDE_ICRS[-19.5/-17.4] Declination (ICRS) at Epoch=2015.5degpos.eq.dec;meta.mainGmag[16.34/20.23] Gaia EDR3 G-band magnitudemagphot.mag;em.optfloatpmRA[-5.8/1.8] Gaia EDR3 Proper motion in Right Ascensionmas/yrpos.pm;pos.eq.rafloatpmDE[-2.1/1.5] Gaia EDR3 Proper motion in Declinationmas/yrpos.pm;pos.eq.decfloatHRV[-32/367] Heliocentric Radial Velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRV[0.8/10] Uncertainty in HRVkm/sstat.errorfloat[Fe/H]1[-3.3/0.06] Metallicity, S5 data release (DR2.2)phys.abund.Zfloate_[Fe/H]1[0.03/99] Uncertainty in [Fe/H]1stat.error;phys.abund.Fefloat[Fe/H]2[-4.5/0.6] Metallicity, higher-resolution red calcium triplet (CaT)phys.abund.Zfloate_[Fe/H]2[0.1/3] Uncertainty in [Fe/H]2stat.error;phys.abund.FefloatBin[YN] Binary Flagmeta.codecharMm[0/1] Membership probabilitystat.probability;meta.code.memberfloatS/N[3/26.4] Spectra Signal to Noisestat.snrfloat