J/MNRAS/435/1928ivo://CDS.VizieR/J/MNRAS/435/1928doi:10.26093/cds/vizier.74351928CDSPawlowski M.S.Kroupa P.Jerjen H.2024-08-06T20:16:59Z2014-11-07T12:41:22ZCDS support team

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

cds-question@unistra.frgalaxiesBoth major galaxies in the Local Group (LG) are surrounded by thin planes of mostly co-orbiting satellite galaxies, the vast polar structure (VPOS) around the Milky Way (MW) and the Great Plane of Andromeda (GPoA) around M31. We summarize the current knowledge concerning these structures and compare their relative orientations by re-determining their properties in a common coordinate system. The existence of similar, coherent structures around both major LG galaxies motivates an investigation of the distribution of the more distant non-satellite galaxies in the LG. This results in the discovery of two planes (diameters of 1-2Mpc) which contain almost all nearby non-satellite galaxies. The two LG planes are surprisingly symmetric. They are inclined by only 20{deg} relative to the galactic disc of M31, are similarly thin (heights of {approx}60kpc) and have near-to-identical offsets from the MW and from M31. They are inclined relative to each other by 35{deg}. Comparing the plane orientations with each other and with additional features reveals indications for an intimate connection between the VPOS and the GPoA. They are both polar with respect to the MW, have similar orbital directions and are inclined by about 45{deg}+/-7{deg} relative to each other. The Magellanic Stream approximately aligns with the VPOS and the GPoA, but also shares its projected position and line-of-sight velocity trend with a part of the dominating structure of non-satellite dwarf galaxies. In addition, the recent proper motion measurement of M31 indicates a prograde orbit of the MW-M31 system, the VPOS and the GPoA. The alignment with other features such as the Supergalactic Plane and the overdensity in hypervelocity stars are discussed as well. We end with a short summary of the currently proposed scenarios trying to explain the LG galaxy structures as either originating from cosmological structures or from tidal debris of a past galaxy encounter. We emphasize that there currently exists no full detailed model which satisfactorily explains the existence of the thin symmetric LG planes.2013MNRAS.435.1928Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/435/1928CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/144/4 : Properties of dwarf galaxies in Local Group (McConnachie+, 2012)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/435/1928https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/435/1928http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/435/1928https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/435/1928https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/435/1928http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/435/1928GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/435/1928/table4 (Distances and offsets (minimum distance) of galaxies from the MW, M31 and the galaxy planes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/435/1928/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/435/1928/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/435/1928/table4?GETtext/xml+votable180.050000true6/619 2110 2155 2216 2234 2272 2297 2565 2572-2573 2604 2611 2622 2628 2668 2676 2709 2746 2755 2758 2767 2774 2777 2781 2789 2830 2852 2953 3042 4410 4419 5287 5919 5939 6021 7265 7416 8745 10183 10308 10444 10769 13505 13655 13720 14149 17165 17229 18041 18926 19833 19990 20262 20416 20437 20440 26487 26980 27000 27207 27580 28136 28361 29699 29718 31692 33096 33317 35206 35720 35969 39100 39860 45423 48035 48942https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/435/1928?format=asciiOpticaldefaultJ/MNRAS/435/1928/table4Distances and offsets (minimum distance) of galaxies from the MW, M31 and the galaxy planesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGalaxy namemeta.id;meta.mainchardMWGalaxy distance from the centre of the MWkpcpos.distancefloatdM31Galaxy distance from the centre of M31kpcpos.distancefloatCatGalaxy category (1)meta.codechardVPOSOffset to all vast polar structure plane (2)kpcpos.distancefloate_dVPOSrms uncertainty on dVPOSkpcstat.errorfloatn_dVPOS[*] * : galaxy to which the offset are fittedmeta.notechardVPOS-3Offset to the VPOS-3 plane (2)kpcpos.distancefloate_dVPOS-3rms uncertainty on dVPOS-3kpcstat.errorfloatn_dVPOS-3[*] * : galaxy to which the offset are fittedmeta.notechardGPoAOffset to Great Plane of Andromeda (2)kpcpos.distancefloate_dGPoArms uncertainty on dGPoAkpcstat.errorfloatn_dGPoA[*] * : galaxy to which the offset are fittedmeta.notechardLGP1Offset to Local Group Plane 1 (LGP1) (2)kpcpos.distancefloate_dLGP1rms uncertainty on dLGP1kpcstat.errorfloatn_dLGP1[*] * : galaxy to which the offset are fittedmeta.notechardLGP2Offset to Local Group Plane 2 (LGP2) (2)kpcpos.distancefloate_dLGP2rms uncertainty on dLGP2kpcstat.errorfloatn_dLGP2[*] * : galaxy to which the offset are fittedmeta.notechardM31pOffset to M31 disc planekpcpos.distancefloate_dM31prms uncertainty on dM31pkpcstat.errorfloatn_dM31p[*] * : galaxy to which the offset are fittedmeta.notecharSimbadNameSimbad column added by the CDSmeta.idchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.mainnullable_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainnullable