“School of Astronomy”

Back to Papers Home
Back to Papers of School of Astronomy

Paper   IPM / Astronomy / 13760
School of Astronomy
  Title:   Evolution of the galaxy luminosity function in progenitors of fossil groups
  Author(s): 
1.  G. Gozaliasl
2.  H. G. Khosroshahi
3.  A.A. Dariush
4.  A. Finoguenov
5.  D.M.Z. Jassur
6.  A. Molaeinezhad
  Status:   Published
  Journal: Astronomy & Astrophysics
  Vol.:  571
  Year:  2014
  Pages:   13 pp
  Supported by:  IPM
  Abstract:
Using the semi-analytic models based on the Millennium simulation, we trace back the evolution of the luminosity function of galaxies residing in progenitors of groups classified by the magnitude gap at redshift zero. We determine the luminosity function of galaxies within 0.25R_{200}, 0.5R_{200} , and R_{200} for galaxy groups/clusters. The bright end of the galaxy luminosity function of fossil groups shows a significant evolution with redshift, with changes in M^* by \sim 1-2 mag between z\sim0.5 and z=0 (for the central 0.5R_{200}), suggesting that the formation of the most luminous galaxy in a fossil group has had a significant impact on the M^{*} galaxies e.g. it is formed as a result of multiple mergers of the M^{*} galaxies within the last \sim5 Gyr. In contrast, the slope of the faint end, \alpha, of the luminosity function shows no considerable redshift evolution and the number of dwarf galaxies in the fossil groups exhibits no evolution, unlike in non-fossil groups where it grows by \sim25-42\% towards low redshifts. In agreement with previous studies, we also show that fossil groups accumulate most of their halo mass earlier than non-fossil groups. Selecting the fossils at a redshift of 1 and tracing them to a redshift 0, we show that 80\% of the fossil groups (10^{13} M_{\odot} h^{-1}10^{14} M_{\odot} h^{-1}) will retain their large gaps.

Download TeX format
back to top
scroll left or right