School of Astronomy

School of Astronomy (SoA) Weekly Seminar

Central galaxies of fossil groups in the Millennium simulation

Ali Koohpaee (Khaje Nasir Univ. & IPM)

Abstract:

Fossil galaxy groups have been the focus of several observational and numerical studies. Fossil groups are characterised by a large luminosity gap between the two brightest galaxies in the group, while the control samples are selected to represent groups with low and medium luminosity gaps.The present study concentrates on the stellar properties and evolution of their dominant galaxy using \cite{bow06} semi-analytic model. We compute the stellar properties of the brightest galaxies in fossils and control groups to explore the differences in their star formation and merger history. Our findings show that the dominant galaxies in groups with large luminosity gaps, namely fossil groups, are special in their stellar properties (e.g. star formation and merger history). The above evidences point at early formation of fossil groups. Although recent observational studies of the dominant galaxies in groups characterised by the luminosity gap seem to arrive at similar conclusions, however, more detailed studies of the stellar population of these galaxies are needed.

Wednesday / 23 Sep. 2009 / 1 Mehr 1388/ 2:00 PM
IPM Larak Building, School of Astronomy

Address: Larak Garden, opposite Araj, Artesh Highway,Tehran, Iran
E-mail: astro(at)ipm.ir