Open AccessMass estimation in the outer regions of galaxy clusters
Author(s) -
Diaferio Antonaldo
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02864.x
Subject(s) - physics , astrophysics , galaxy , galaxy cluster , cluster (spacecraft) , redshift , brightest cluster galaxy , cluster sampling , projection (relational algebra) , sky , cluster analysis , galaxy formation and evolution , statistical physics , algorithm , statistics , population , demography , mathematics , sociology , computer science , programming language
We present a technique for estimating the mass in the outskirts of galaxy clusters where the usual assumption of dynamical equilibrium is not valid. The method assumes that clusters form through hierarchical clustering and requires only galaxy redshifts and positions on the sky. We apply the method to dissipationless cosmological N ‐body simulations where galaxies form and evolve according to semi‐analytic modelling. The method recovers the actual cluster mass profile within a factor of 2 to several megaparsecs from the cluster centre. This error originates from projection effects, sparse sampling, and contamination by foreground and background galaxies. In the absence of velocity biases, this method can provide an estimate of the mass‐to‐light ratio on scales ∼1–10 h −1 Mpc where this quantity is still poorly known.