A six-parameter space to describe galaxy diversification - Archive ouverte HAL Access content directly
Journal Articles Astronomy and Astrophysics - A&A Year : 2012

A six-parameter space to describe galaxy diversification


Galaxy diversification proceeds by transforming events like accretion, interaction or mergers. These explain the formation and evolution of galaxies that can now be described with many observables. Multivariate analyses are the obvious tools to tackle the datasets and understand the differences between different kinds of objects. However, depending on the method used, redundancies, incompatibilities or subjective choices of the parameters can void the usefulness of such analyses. The behaviour of the available parameters should be analysed before an objective reduction of dimensionality and subsequent clustering analyses can be undertaken, especially in an evolutionary context. We study a sample of 424 early-type galaxies described by 25 parameters, ten of which are Lick indices, to identify the most structuring parameters and determine an evolutionary classification of these objects. Four independent statistical methods are used to investigate the discriminant properties of the observables and the partitioning of the 424 galaxies: Principal Component Analysis, K-means cluster analysis, Minimum Contradiction Analysis and Cladistics. (abridged)
Fichier principal
Vignette du fichier
multivargal.pdf (2.08 Mo) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

hal-00708735 , version 1 (15-06-2012)
hal-00708735 , version 2 (04-07-2012)



Didier Fraix-Burnet, Tanuka Chattopadhyay, Asis Kumar Chattopadhyay, Emmanuel Davoust, Marc Thuillard. A six-parameter space to describe galaxy diversification. Astronomy and Astrophysics - A&A, 2012, 545, pp.A80. ⟨10.1051/0004-6361/201218769⟩. ⟨hal-00708735v2⟩
360 View
238 Download



Gmail Facebook Twitter LinkedIn More