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dc.contributor.authorCollins, Michelle L. M.
dc.contributor.authorTollerud, Erik J.
dc.contributor.authorSand, David J.
dc.contributor.authorBonaca, Ana
dc.contributor.authorWillman, Beth
dc.contributor.authorStrader, Jay
dc.date.accessioned2017-06-05T20:43:18Z
dc.date.available2017-06-05T20:43:18Z
dc.date.issued2017-01-12
dc.identifier.citationDynamical evidence for a strong tidal interaction between the Milky Way and its satellite, Leo V 2017:stx067 Monthly Notices of the Royal Astronomical Societyen
dc.identifier.issn0035-8711
dc.identifier.issn1365-2966
dc.identifier.doi10.1093/mnras/stx067
dc.identifier.urihttp://hdl.handle.net/10150/623924
dc.description.abstractWe present a chemodynamical analysis of the Leo V dwarf galaxy, based on the Keck II DEIMOS spectra of eight member stars. We find a systemic velocity for the system of nu(r) = 170.9(+2.1) (-1.9) km s(-1) and barely resolve a velocity dispersion for the system, with sigma nu(r) = 2.3(+3.2) (-1.6) km s(-1), consistent with previous studies of Leo V. The poorly resolved dispersion means we are unable to adequately constrain the dark-matter content of Leo V. We find an average metallicity for the dwarf of [ Fe/ H] =-2.48 +/- 0.21 and measure a significant spread in the iron abundance of its member stars, with -3.1 <= [ Fe/ H] <=-1.9 dex, which clearly identifies Leo V as a dwarf galaxy that has been able to self-enrich its stellar population through extended star formation. Owing to the tentative photometric evidence for the tidal substructure around Leo V, we also investigate whether there is any evidence for tidal stripping or shocking of the system within its dynamics. We measure a significant velocity gradient across the system, of dv d chi = -4.1(+2.8) (-2.6) km s(-1) arcmin(-1) ( or d nu/d chi=-71.9(vertical bar 50.8) (-45.6) km s(-1) kpc(-1)), which points almost directly towards the Galactic Centre. We argue that Leo V is likely a dwarf on the brink of dissolution, having just barely survived a past encounter with the centre of the Milky Way.
dc.description.sponsorshipEuropean Research Council [ERCStG-335936]; NASA through Hubble Fellowship [51337]; Space Telescope Science Institute [NAS 5-26555, 51316.01]; NSF [AST-1412504, AST-1517649, PHY-1066293, AST-1514763, AST-1151462]; Packard Fellowshipen
dc.language.isoenen
dc.publisherOXFORD UNIV PRESSen
dc.relation.urlhttps://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stx067en
dc.rights© 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.en
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjectgalaxies: dwarfen
dc.subjectgalaxies: evolutionen
dc.subjectgalaxies: individualen
dc.subjectgalaxies: kinematics and dynamicsen
dc.subjectLocal Groupen
dc.titleDynamical evidence for a strong tidal interaction between the Milky Way and its satellite, Leo Ven
dc.typeArticleen
dc.contributor.departmentUniv Arizona, Steward Observen
dc.contributor.departmentUniv Arizona, LSSTen
dc.identifier.journalMonthly Notices of the Royal Astronomical Societyen
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
refterms.dateFOA2018-09-11T19:53:47Z
html.description.abstractWe present a chemodynamical analysis of the Leo V dwarf galaxy, based on the Keck II DEIMOS spectra of eight member stars. We find a systemic velocity for the system of nu(r) = 170.9(+2.1) (-1.9) km s(-1) and barely resolve a velocity dispersion for the system, with sigma nu(r) = 2.3(+3.2) (-1.6) km s(-1), consistent with previous studies of Leo V. The poorly resolved dispersion means we are unable to adequately constrain the dark-matter content of Leo V. We find an average metallicity for the dwarf of [ Fe/ H] =-2.48 +/- 0.21 and measure a significant spread in the iron abundance of its member stars, with -3.1 <= [ Fe/ H] <=-1.9 dex, which clearly identifies Leo V as a dwarf galaxy that has been able to self-enrich its stellar population through extended star formation. Owing to the tentative photometric evidence for the tidal substructure around Leo V, we also investigate whether there is any evidence for tidal stripping or shocking of the system within its dynamics. We measure a significant velocity gradient across the system, of dv d chi = -4.1(+2.8) (-2.6) km s(-1) arcmin(-1) ( or d nu/d chi=-71.9(vertical bar 50.8) (-45.6) km s(-1) kpc(-1)), which points almost directly towards the Galactic Centre. We argue that Leo V is likely a dwarf on the brink of dissolution, having just barely survived a past encounter with the centre of the Milky Way.


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