dc.contributor.author Collaboration, Gaia en dc.contributor.author Helmi, A en dc.contributor.author Leeuwen, F van en dc.contributor.author McMillan, PJ en dc.contributor.author Massari, D en dc.contributor.author Antoja, T en dc.contributor.author Robin, A en dc.contributor.author Lindegren, L en dc.contributor.author Bastian, U en dc.contributor.author co-authors, en dc.date.accessioned 2018-09-26T12:11:55Z dc.date.available 2018-09-26T12:11:55Z dc.identifier.issn 0004-6361 dc.identifier.uri https://www.repository.cam.ac.uk/handle/1810/280731 dc.description.abstract Aims. The goal of this paper is to demonstrate the outstanding quality of the second data release of the Gaia mission and its power for constraining many di erent aspects of the dynamics of the satellites of the Milky Way. We focus here on determining the proper motions of 75 Galactic globular clusters, nine dwarf spheroidal galaxies, one ultra-faint system, and the Large and Small Magellanic Clouds. Methods. Using data extracted from the Gaia archive, we derived the proper motions and parallaxes for these systems, as well as their uncertainties. We demonstrate that the errors, statistical and systematic, are relatively well understood. We integrated the orbits of these objects in three different Galactic potentials, and characterised their properties. We present the derived proper motions, space velocities, and characteristic orbital parameters in various tables to facilitate their use by the astronomical community. Results. Our limited and straightforward analyses have allowed us for example to (i) determine absolute and very precise proper motions for globular clusters; (ii) detect clear rotation signatures in the proper motions of at least five globular clusters; (iii) show that the satellites of the MilkyWay are all on high-inclination orbits, but that they do not share a single plane of motion; (iv) derive a lower limit for the mass of the Milky Way of 9:8$^{+6:7}_{2:7}$ x 10$6{11}$$\odot$ based on the assumption that the Leo I dwarf spheroidal is bound; (v) derive a rotation curve for the Large Magellanic Cloud based solely on proper motions that is competitive with line-of-sight velocity curves, now using many orders of magnitude more sources; and (vi) unveil the dynamical effect of the bar on the motions of stars in the Large Magellanic Cloud. Conclusions. All these results highlight the incredible power of the Gaia astrometric mission, and in particular of its second data release. dc.description.sponsorship Includes STFC and ERC. dc.publisher EDP Sciences dc.subject Galaxy: kinematics and dynamics en dc.subject Galaxy: halo, Magellanic Clouds en dc.subject globular clusters: general en dc.subject galaxies: dwarf, Local Group en dc.subject methods: data analysis, astrometry en dc.title Gaia Data Release 2: Kinematics of globular clusters and dwarf galaxies around the Milky Way en dc.type Article prism.number A12 en prism.publicationName Astronomy & Astrophysics en prism.volume 616 en dc.identifier.doi 10.17863/CAM.28095 dcterms.dateAccepted 2018-03-28 en rioxxterms.versionofrecord 10.1051/0004-6361/201832698 en rioxxterms.licenseref.uri http://www.rioxx.net/licenses/all-rights-reserved en rioxxterms.licenseref.startdate 2018-03-28 en dc.identifier.eissn 1432-0746 rioxxterms.type Journal Article/Review en pubs.funder-project-id STFC (ST/K000756/1) pubs.funder-project-id STFC (ST/L006553/1) pubs.funder-project-id STFC (ST/N000641/1) pubs.funder-project-id STFC (PP/D006546/1) pubs.funder-project-id STFC (ST/I000542/1) pubs.funder-project-id STFC (ST/J005045/1) pubs.funder-project-id PPARC (PP/C000757/1) pubs.funder-project-id STFC (ST/P000975/1) pubs.funder-project-id STFC (ST/S000089/1) cam.issuedOnline 2018-08-10 en cam.orpheus.success Thu Jan 30 10:54:28 GMT 2020 - The item has an open VoR version. * rioxxterms.freetoread.startdate 2100-01-01
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