The masses of local group dwarf spheroidal galaxies : the death of the universal mass profile

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DOIResolve DOI: http://doi.org/10.1088/0004-637X/783/1/7
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TypeArticle
Journal titleThe Astrophysical Journal
ISSN0004-637X
Volume783
Issue1
Article number7
Pages114; # of pages: 14
Subjectdark matter; galaxies: dwarf; galaxies: fundamental parameter; galaxies: kinematics and dynamics; Local Group
AbstractWe investigate the claim that all dwarf spheroidal galaxies (dSphs) reside within halos that share a common, universal mass profile as has been derived for dSphs of the galaxy. By folding in kinematic information for 25 Andromeda dSphs, more than doubling the previous sample size, we find that a singular mass profile cannot be found to fit all of the observations well. Further, the best-fit dark matter density profile measured solely for the Milky Way dSphs is marginally discrepant with that of the Andromeda dSphs (at just beyond the 1σ level), where a profile with lower maximum circular velocity, and hence mass, is preferred. The agreement is significantly better when three extreme Andromeda outliers, And XIX, XXI, and XXV, all of which have large half-light radii (≳ 600 pc) and low-velocity dispersions (σ v <5 km s-1), are omitted from the sample. We argue that the unusual properties of these outliers are likely caused by tidal interactions with the host galaxy.
Publication date
LanguageEnglish
AffiliationNational Research Council Canada (NRC-CNRC); National Science Infrastructure
Peer reviewedYes
NPARC number21273042
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Record identifier63bf0022-72e4-49b4-9ef7-8ccdcf8044d6
Record created2014-12-09
Record modified2016-07-18
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