A lower limit on Omega(m)-Omega(Lambda) using gravitational lensing in theHubble Deep Field

Citation
Ar. Cooray et al., A lower limit on Omega(m)-Omega(Lambda) using gravitational lensing in theHubble Deep Field, ASTROPHYS J, 511(2), 1999, pp. 562-568
Citations number
27
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
511
Issue
2
Year of publication
1999
Part
1
Pages
562 - 568
Database
ISI
SICI code
0004-637X(19990201)511:2<562:ALLOOU>2.0.ZU;2-J
Abstract
We calculate the expected number of multiply imaged galaxies in the Hubble Deep Field (HDF), using photometric redshift information for galaxies with m(I) < 27 that were detected in all four HDF passbands. A comparison of the se expectations with the observed number of strongly lensed galaxies places a lower limit on the current value of Omega(m) - Omega(Lambda), where Omeg a(m) is the cosmological mass density of the universe and Omega(Lambda) is the normalized cosmological constant. Based on current estimates of the HDF luminosity function and associated uncertainties in individual parameters, our 95% confidence lower limit on Omega(m) - Omega(Lambda) is between -0.4 4, if there are no strongly lensed galaxies in the HDF, and -0.73, if there are two strongly lensed galaxies in the HDF. For a flat universe (Omega(m) + Omega(Lambda) = 1), Omega(Lambda) < 0.58-0.79 (95% confidence limit). If the only lensed galaxy in the HDF is the one presently viable candidate, t hen in a flat universe (Omega(m) + Omega(Lambda) = 1), Omega(Lambda) < 0.79 (95% confidence limit). These lower limits are compatible with estimates b ased on high-redshift supernovae and with previous limits based on gravitat ional lensing.