The distribution of matter around luminous galaxies

Conference · Sat Jun 01 04:00:00 EDT 1996

OSTI ID:251365

Bromley, B C; Laflamme, R; Warren, M S; Zurek, W H

The authors discuss the dynamical implications of a measure proposed by Jim Peebles which is the cosmic mass density of material within some fixed distance of a luminous galaxy. If all the matter in the Universe were strongly correlated with galaxies, then this measure rises rapidly to the standard cosmic mass density as expressed in the parameter{Omega}. With numerical simulations they show that in both standard and low-mass CDM models only half of the mass of the Universe lies within a megaparsec or so of a galaxy of luminosity of roughly L{sub *} or brighter. The implications of this clustering property are considerable for conventional mass measures which treat galaxies as point particles. They explore two such measures, based on the Least Action Method and the Cosmic Virial Theorem. In the former case, the method is not likely to work on scales of a typical intergalaxy spacing; however, it may perform nicely in estimating the mass of an isolated set of galaxy groups or poor clusters. In the case of the Cosmic Virial Theorem, they find that having a large fraction of the mass in the Universe located at some distance from galaxies brings in potentially severe problems of bias which can introduce large uncertainties in the estimation of {Omega}.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 251365
• Report Number(s): LA-UR--96-1761; CONF-960192--2; ON: DE96011292
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COSMOLOGICAL MODELS
GALAXIES
GALAXY CLUSTERS
MASS DISTRIBUTION
NONLUMINOUS MATTER
UNIVERSE