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Structural analysis of the Sextans dwarf spheroidal galaxy

Roderick, Tammy; Jerjen, Helmut; Da Costa, Gary; Mackey, Dougal

Description

We present wide-field g- and i-band stellar photometry of the Sextans dwarf spheroidal galaxy and its surrounding area out to four times its half-light radius (rh = 695 pc), based on images obtained with the Dark Energy Camera at the 4-m Blanco telescope at CTIO. We find clear evidence of stellar substructure associated with the galaxy, extending to a distance of 82 arcmin (2 kpc) from its centre. We perform a statistical analysis of the overdensities and find three distinct features, as well...[Show more]

dc.contributor.authorRoderick, Tammy
dc.contributor.authorJerjen, Helmut
dc.contributor.authorDa Costa, Gary
dc.contributor.authorMackey, Dougal
dc.date.accessioned2018-11-29T22:53:46Z
dc.date.available2018-11-29T22:53:46Z
dc.identifier.issn0035-8711
dc.identifier.urihttp://hdl.handle.net/1885/152565
dc.description.abstractWe present wide-field g- and i-band stellar photometry of the Sextans dwarf spheroidal galaxy and its surrounding area out to four times its half-light radius (rh = 695 pc), based on images obtained with the Dark Energy Camera at the 4-m Blanco telescope at CTIO. We find clear evidence of stellar substructure associated with the galaxy, extending to a distance of 82 arcmin (2 kpc) from its centre. We perform a statistical analysis of the overdensities and find three distinct features, as well as an extended halo-like structure, to be significant at the 99.7 per cent confidence level or higher. Unlike the extremely elongated and extended substructures surrounding the Hercules dwarf spheroidal galaxy, the overdensities seen around Sextans are distributed evenly about its centre, and do not appear to form noticeable tidal tails. Fitting a King model to the radial distribution of Sextans stars yields a tidal radius rt = 83.2 arcmin ± 7.1 arcmin (2.08 ± 0.18 kpc), which implies the majority of detected substructure is gravitationally bound to the galaxy. This finding suggests that Sextans is not undergoing significant tidal disruption from the Milky Way, supporting the scenario in which the orbit of Sextans has a low eccentricity.
dc.format.mimetypeapplication/pdf
dc.publisherBlackwell Publishing Ltd
dc.sourceMonthly Notices of the Royal Astronomical Society
dc.titleStructural analysis of the Sextans dwarf spheroidal galaxy
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume460
dc.date.issued2016
local.identifier.absfor020100 - ASTRONOMICAL AND SPACE SCIENCES
local.identifier.ariespublicationu4571891xPUB11
local.type.statusPublished Version
local.contributor.affiliationRoderick, Tammy, College of Science, ANU
local.contributor.affiliationJerjen, Helmut, College of Science, ANU
local.contributor.affiliationDa Costa, Gary, College of Science, ANU
local.contributor.affiliationMackey, Dougal, College of Science, ANU
local.bibliographicCitation.issue1
local.identifier.doi10.1093/mnras/stw949
local.identifier.absseo970102 - Expanding Knowledge in the Physical Sciences
dc.date.updated2018-11-29T07:55:06Z
local.identifier.scopusID2-s2.0-84979075877
local.identifier.thomsonID000379835200004
dcterms.accessRightsOpen Access
CollectionsANU Research Publications

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