Determination of ΩΛ and H0 from photometric data of radiogalaxies

From photometric observations of elliptical galaxies, among which are both radio galaxies and radio-quiet objects, an investigation was carried out of the relationship ‘redshift – age of the stellar system’ (∆z/∆t). By means of this relationship cosmological parameters H(z) and ΩΛ are estimated. Ages of stellar systems are determined within the framework of evolution models of synthetic spectra PEGASE and GISSEL. This approach can be considered as time study of objects of the early Universe independent of other cosmological models. Construction of a pooled sample is described, containing 220 objects from different populations of elliptical galaxies, for which an analysis of the upper limit of the age of formation of a stellar system was performed. These data were used to estimate the boundaries of determination of the cosmological parameters H0 and Λ–term: H0 = 72± 10 and ΩΛ = 0.8± 0.1 in the model GISSEL and H0 = 53± 10, and ΩΛ = 0.8± 0.1 in the model PEGASE.