Velocity dispersion, mass and the luminosity function of the fossil cluster rx j1416.4+2315.

• Grant number: 07/00180-8
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: February 01, 2007
• End date: April 30, 2007
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Laerte Sodré Junior
• Grantee: Laerte Sodré Junior
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

We study the properties of the fossil cluster RX J1416.4+2315 through g'- and i'-band imaging and spectroscopy of 25 member galaxies. The system is at a mean redshift of 0.137 and has a velocity dispersion of 584 km/s. Superposed onto one quadrant of the cluster field is a group of five galaxies at a mean redshift of 0.131, which, if included as part of the cluster, increases the velocity dispersion to 846 km/s. The central object of RX J1416.4+2315 is a normal elliptical galaxy with no cD envelope. The luminosity function of the system, estimated by the number counts and statistical background correction in the range -22.6