Astronomy and Astrophysics – Astrophysics
Scientific paper
1995-01-09
Astronomy and Astrophysics
Astrophysics
10 pages, uuencoded compressed postscript file, including 2 figures. also available from ftp://magicbean.berkeley.edu/pub/marc
Scientific paper
10.1063/1.48359
Recent progress in the measurement of relative distances to galaxies has been quite substantial, and catalogs of 3000 galaxies with distances are soon to become available. The peculiar {\it velocity} field (deviations from Hubble flow) derivable from these catalogs, when compared to the peculiar {\it gravity} field derived from all sky redshift surveys of galaxies such as the 1.2Jy IRAS survey, leads to a unique and extremely powerful test of the density parameter $\beta \equiv \Omega^{0.6}/b_I$, where $b_I$ is the possible linear bias of the IRAS selected galaxies relative to the mass fluctuations. We review the status of these large scale flow measurements and present a new methodology to describe the two fields by means of an expansion in a set of orthogonalized functions describing a general potential flow to any chosen resolution. The parameters of the flow can be estimated by minimization of the $\chi^2$ describing the scatter of observed versus predicted linewidths from an inverse Tully-Fisher relation. By this method one can intercompare the gravity and velocity fields coefficient by coefficient, deriving a precise fit for the density parameter and an assessment of the degree of coherence between the fields. The present situation is transitory-- different analyses of the same data are not yielding consistent results. Until this embarassment is untangled, estimates of $\beta$ should be taken with a large grain of salt.
Davis Martin
Nusser Adi
No associations
LandOfFree
INDICATIONS OF DARK MATTER DERIVED FROM LARGE SCALE FLOWS 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 INDICATIONS OF DARK MATTER DERIVED FROM LARGE SCALE FLOWS, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and INDICATIONS OF DARK MATTER DERIVED FROM LARGE SCALE FLOWS will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-152690