Kinematics, substructure and luminosity-weighted dynamics of six nearby galaxy groups

P. Firth*, E. A. Evstigneeva, J. B. Jones, M. J. Drinkwater, S. Phillipps, M. D. Gregg

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

28 Citations (Scopus)

Abstract

We have redefined group membership of six southern galaxy groups in the local universe (mean cz <2000 km s(-1)) based on new redshift measurements from our recently acquired Anglo-Australian Telescope 2dF spectra. For each group, we investigate member galaxy kinematics, substructure, luminosity functions and luminosity-weighted dynamics. Our calculations confirm that the group sizes, virial masses and luminosities cover the range expected for galaxy groups, except that the luminosity of NGC 4038 is boosted by the central starburst merger pair. We find that a combination of kinematical, substructural and dynamical techniques can reliably distinguish loose, unvirialized groups from compact, dynamically relaxed groups. Applying these techniques, we find that Dorado, NGC 4038 and NGC 4697 are unvirialized, whereas NGC 681, NGC 1400 and NGC 5084 are dynamically relaxed.

Original languageEnglish
Pages (from-to)1856-1868
Number of pages13
JournalMonthly Notices of the Royal Astronomical Society
Volume372
Issue number4
DOIs
Publication statusPublished - 11 Nov 2006

Keywords

  • galaxies : distances and redshifts
  • galaxies : kinematics and dynamics
  • VIRIAL MASSES
  • SKY SURVEY
  • CLUSTERS
  • CATALOG
  • POPULATION
  • SYSTEMS
  • TESTS

Cite this