Do the Redshifts of Gravitational Lens Galaxies Rule Out a Large Cosmological Constant?
Abstract
The distribution of lens galaxy redshifts in known gravitational lens systems is an extremely powerful means of discriminating between some cosmologies. Standard cosmologies are 510 times more probable than flat large cosmological constant cosmologies with λ_0_ >~ 0.9 based on the existing small sample. A few additional gravitational lens systems produced by isolated galaxies with known source and lens redshifts would settle the question, because the probability of the redshift distribution in an Einsteinde Sitter universe agreeing with the flat λ_0_ >~ 0.9 models drops faster than proportional to (0.5)^N^, where N is the number of systems. The uncertainties in the mass distribution of galaxies are larger than the differences between standard FRW {OMEGA}_0_ = 0 to {OMEGA}_0_ = 1 models. If we confine ourselves to Einsteinde Sitter cosmologies, we can predict redshifts for several of the lenses in which they are not currently known. If we model the lens galaxies as ellipticals, then the predicted redshifts of the lens galaxy for the gravitational lenses PG 1115+080 and 1413+117 are z_L_= 0.37+/0.18 (0.48 +/ 0.22) and Z_L_ = 0.68 +/ 0.33, (0.92+/0.40) where the errors correspond to one standard deviation in the redshift probability distribution, and the two sets of ranges correspond to σ_m_ = σ or σ_m_ = (3/2)^1/2^{sigma}, where σ_m_ is the velocity dispersion characteristic of the mass distribution, and σ is the measured velocity dispersion.
 Publication:

The Astrophysical Journal
 Pub Date:
 January 1992
 DOI:
 10.1086/170845
 Bibcode:
 1992ApJ...384....1K
 Keywords:

 Cosmology;
 Galaxies;
 Gravitational Lenses;
 Red Shift;
 Astronomical Models;
 Einstein Equations;
 Astrophysics;
 COSMOLOGY: GRAVITATIONAL LENSING;
 COSMOLOGY: OBSERVATIONS;
 GALAXIES: DISTANCES AND REDSHIFTS