The structure of star clusters in the outer halo of M31

Download
  1. Get@NRC: The structure of star clusters in the outer halo of M31 (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1111/j.1365-2966.2012.20590.x
AuthorSearch for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for:
TypeArticle
Journal titleMonthly Notices of the Royal Astronomical Society
ISSN0035-8711
Volume422
Issue1
Pages162184; # of pages: 23
AbstractWe present a structural analysis of halo star clusters in M31 based on deep Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) imaging. The clusters in our sample span a range in galactocentric projected distance from 13 to 100kpc and thus reside in rather remote environments. Ten of the clusters are classical globulars, whilst four are from the Huxor et al. population of extended, old clusters. For most clusters, contamination by M31 halo stars is slight, and so the profiles can be mapped reliably to large radial distances from their centres. We find that the extended clusters are well fit by analytic King profiles with ∼20 parsec core radii and ∼100 parsec photometric tidal radii, or by Sérsic profiles of index ∼1 (i.e. approximately exponential). Most of the classical globulars also have large photometric tidal radii in the range 50-100 parsec; however, the King profile is a less good fit in some cases, particularly at small radii. We find 60 percent of the classical globular clusters exhibit cuspy cores which are reasonably well described by Sérsic profiles of index ∼2-6. Our analysis also reinforces the finding that luminous classical globulars, with half-light radii <10 parsec, are present out to radii of at least 100kpc in M31, which is in contrast to the situation in the Milky Way where such clusters (other than the unusual object NGC 2419) are absent beyond 40kpc.
Publication date
LanguageEnglish
AffiliationNational Research Council Canada (NRC-CNRC); National Science Infrastructure
Peer reviewedYes
NPARC number21270266
Export citationExport as RIS
Report a correctionReport a correction
Record identifiera1ba685f-71d4-4e5a-8e39-f7f86d32f70b
Record created2014-01-17
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)