X-ray clusters and gravitiational instability theories

Details X-ray clusters and gravitiational instability theories X-ray clusters and gravitiational instability theories

Feb 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994apj...422..443c&link_type=abstract

Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 422, no. 2, p. 443-458

Astronomy and Astrophysics

Astrophysics

30

Astronomical Models, Background Radiation, Cosmology, Dark Matter, Galactic Clusters, Galactic Evolution, Gravitation Theory, Mathematical Models, Microwave Emission, Missing Mass (Astrophysics), X Ray Astronomy, Anisotropy, Heao 2, Luminosity, Luminous Intensity

Scientific paper

We discuss the expected evolution of X-ray clusters of galaxies in different models for structure formation: these are cold dark matter, hybrid, and baryonic isocurvature models. We compare the theoretical predictions with the observed X-ray local luminosity function and with the counts obtained from the Extended Medium Sensitivity Survey (EMSS) of the HEAO 2 satellite. For properly comparing our predictions with the EMSS data we apply several corrections to the theoretical X-ray luminosities and fluxes. We find that the most effective correction comes from considering the finite size of the EMSS detection cell in the HEAO 2 Imaging Proportional Counter cluster images. The available X-ray data are extremely selective. The allow to reject baryonic isocurvature models, as well as hybrid models where hot dark matter provides approximately 30% of the critical density. The model which performs by far better than the others considered here is a low-density (Omega0 = 0.2, h = 0.75) vacuum-dominated cold dark matter model, with an initial scale-free density fluctuation spectrum. In all models, the brighter X-ray clusters are rare objects originating from the high peaks of the initial density field. This implies that optical galaxies are biased tracers of the mass density field, unless the cluster collapse occurs on timescales longer than those of the ideal pressureless sphere. We discuss our results in the light of the Cosmic Background Explorer Satellite - Differential Microwave Radiometer (COBE-DMR) detection of large scale anisotropy of the cosmic microwave background.

Affiliated with

Also associated with

No associations

Rating

X-ray clusters and gravitiational instability theories does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with X-ray clusters and gravitiational instability theories, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and X-ray clusters and gravitiational instability theories will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1014342