NGC 5128 globular clusters

DOI

An objective classification of the globular clusters (GCs) of NGC 5128 has been carried out by using a model-based approach of cluster analysis. The set of observable parameters includes structural parameters, spectroscopically determined Lick indices and radial velocities from the literature. The optimum set of parameters for this type of analysis is selected through a modified technique of principal component analysis, which differs from the classical one in the sense that it takes into consideration the effects of outliers present in the data. Then a mixture model based approach has been used to classify the GCs into groups. The efficiency of the techniques used is tested through the comparison of the misclassification probabilities with those obtained using the K-means clustering technique. On the basis of the above classification scheme three coherent groups of GCs have been found. We propose that the clusters of one group originated in the original cluster formation event that coincided with the formation of the elliptical galaxy, and that the clusters of the two other groups are of external origin, from tidally stripped dwarf galaxies on random orbits around NGC 5128 for one group, and from an accreted spiral galaxy for the other.

Cone search capability for table J/ApJ/705/1533/glcl (Parameters of the globular clusters of NGC 5128 used in Principal Component Analysis (PCA) and Cluster Analysis (CA) and derived parameters)

Identifier
DOI http://doi.org/10.26093/cds/vizier.17051533
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/705/1533
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/705/1533
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/705/1533
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/705/1533
Provenance
Creator Chattopadhyay A.K.; Chattopadhyay T.; Davoust E.; Mondal S.; Sharina M.
Publisher CDS
Publication Year 2012
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Galactic and extragalactic Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy