Galaxy luminosities in 2df percolation-inferred galaxy (2PIGG) groups

Aaron Robotham*, Christopher Wallace, Steven Phillipps, Roberto De Propris

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

20 Citations (Scopus)

Abstract

We derive composite luminosity functions (LF) for galaxies in groups and examine the behavior of the LF as a function of group luminosity (used as an indicator of group or halo mass). We consider both the entire galaxy population and galaxies split into red and blue (quiescent and star-forming) samples, in order to examine possible mechanisms behind observed variations of galaxy properties with environment. We find evidence that M* brightens and alpha steepens with group luminosity, until a threshold value where the LF parameters stabilize at those found in rich clusters. The effect is seen in the total LF and for the blue and red galaxies separately. The behavior of the quiescent and star-forming samples is qualitatively consistent with variations resulting from interactions and mergers, where mergers build the bright end of the luminosity function at the same time as dwarf irregulars have their star formation quenched and evolve into dwarf ellipticals. These processes appear to take place preferentially in low-luminosity groups and to be complete at a group luminosity of -22.5 in B, corresponding to a halo mass of order 10(13.5) M-circle dot.

Original languageEnglish
Pages (from-to)1077-1084
Number of pages8
JournalAstrophysical Journal
Volume652
Issue number2
Publication statusPublished - 1 Dec 2006

Keywords

  • galaxies : clusters : general
  • galaxies : evolution
  • galaxies : formation
  • galaxies : luminosity function, mass function
  • DARK-MATTER HALOES
  • REDSHIFT SURVEY
  • RICH CLUSTERS
  • DWARF GALAXIES
  • STAR-FORMATION
  • ENVIRONMENTAL DEPENDENCE
  • POOR GROUPS
  • X-RAY
  • EVOLUTION
  • MASS

Cite this

Robotham, A., Wallace, C., Phillipps, S., & De Propris, R. (2006). Galaxy luminosities in 2df percolation-inferred galaxy (2PIGG) groups. Astrophysical Journal, 652(2), 1077-1084.