Tracing the origin of the aquarius stream. I

dc.contributor.authorWylie de Boer, Elizabeth
dc.contributor.authorFreeman, Kenneth
dc.contributor.authorWilliams, Mary
dc.contributor.authorSteinmetz, Matthias
dc.contributor.authorMunari, U
dc.contributor.authorKeller, Stefan
dc.description.abstractWe present an abundance analysis of six member stars of the recently discovered Aquarius stream, in an attempt to ascertain whether this halo stream is real and, if so, to understand its origin. The mean metallicities of the six stars have a dispersion of only 0.10 dex, indicating that they are part of a chemically coherent structure. We then investigate whether the stream represents the debris of a disrupted dwarf galaxy or a disrupted globular cluster. The [Ni/Fe]-[Na/Fe] plane provides a good diagnostic: globular cluster stars and dwarf spheroidal galaxy stars are well separated in this plane, and the Aquarius stream stars lie unambiguously in the globular cluster region. The Aquarius stream stars also lie on the distinct [Na/Fe]-[O/Fe] and [Mg/Fe]-[Al/Fe] relations delineated by Galactic globular cluster stars. Spectroscopic parameters for the six Aquarius stars show that they are tightly confined to a 12 Gyr, [Fe/H] =-1.0, α-enhanced isochrone, consistent with their identification as globular cluster debris. We present evidence that the Aquarius stream may continue through the disk and out into the northern halo. Our results indicate a globular cluster origin for the Aquarius stream and demonstrate the potential for chemical tagging to identify the origins of Galactic substructures.
dc.publisherIOP Publishing
dc.rightsAuthor/s retain copyrighten_AU
dc.sourceAstrophysical Journal, The
dc.subjectKeywords: Galaxy: abundances; Galaxy: evolution; Galaxy: stellar content
dc.titleTracing the origin of the aquarius stream. I
dc.typeJournal article
dcterms.accessRightsOpen Accessen_AU
local.contributor.affiliationWylie de Boer, Elizabeth, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationFreeman, Kenneth, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationWilliams, Mary, Astrophysikalisches Institut Potsdam
local.contributor.affiliationSteinmetz, Matthias, Astrophysical Institute Potsdam
local.contributor.affiliationMunari, U, INAF-Osservatorio Astronomico di Padova
local.contributor.affiliationKeller, Stefan, College of Physical and Mathematical Sciences, ANU
local.contributor.authoruidWylie de Boer, Elizabeth, u4040109
local.contributor.authoruidFreeman, Kenneth, u7000399
local.contributor.authoruidKeller, Stefan, u9702857
local.description.notesImported from ARIES
local.identifier.absfor020110 - Stellar Astronomy and Planetary Systems
local.identifier.absfor020100 - ASTRONOMICAL AND SPACE SCIENCES
local.type.statusPublished Version