Luminosity Function of Arakelian Galaxies and Their Environmental Dependences

Abstract

This article proposes a method for constructing the luminosity function of galaxies, which gives a result that is consistent with other methods, is as accurate as other methods, and is simple. Using this method, we constructed the luminosity function of Arakelian galaxies with different morphological types in different environments, included in the CfA2 catalog. The proposed method of identifying groups of galaxies is physically grounded and simple. It was found that both the bright and weak parts of the normalized luminosity function of Arakelian galaxies are higher than the bright and weak parts of the similar function of the total sample CfA2. A similar phenomenon is observed separately for members of groups, as well as for single galaxies. This also applies to small groups with 2 or 3 galaxies, and more populated groups. Spiral galaxies obey these laws. For elliptical galaxies, the picture is not very clear (due to the small number of well-known elliptical Arakelian galaxies). The spatial density of the number of ArG in the M≤-17 range is 0.00068 ± 0.00005 Mpc^-3, which corresponds to 2.7% of the entire sample in this range (for CfA2 (M≤-17) = 0.0254 ± 0.0002 Mpc^-3).

Failure of the hypothesis of accelerated expansion of the universe

“…Such large standard deviations in the absolute magnitude distributions of type Ia supernovae allow us to conclude that when estimating the values of cosmological parameters, it is wrong to take as a basis the absolute magnitude determined by few stars. In Mahtessian et al (2020) showed that in this case the obtained cosmological parameters lead to a violation of the initial assumption that the absolute magnitudes of type Ia supernovae do not change with distance. This violation disappears when the absolute magnitude of supernovae is estimated while estimating the cosmological parameters.…”

“…Assuming that the absolute magnitude of supernovae is constant with distance, we get that the share of dark energy in a flat universe does not exceed 50%. In Mahtessian et al (2020) also obtained another important result that the cosmological model with a zero cosmological parameter describes the universe no worse than the Friedmann-Robertson-Walker model.…”

“…More details about these results can be found in Mahtessian et al (2020) and Mahtessian et al (2022).…”

Testing the evolution of the absolute magnitude of type Ia supernovae and cosmological parameters

“…This diagram and the Hubble c diagram complement each other and give consistent results. A comparison of two models (the Friedman's model of a flat universe and the model of the Universe with a zero cosmological constant) based on different subsamples of supernova stars from the Union (Kowalski et al, 2008) and Union2 (Amanullah et al, 2010) compilations using our absolute magnitude test was carried out in detail by Mahtessian et al (2020).…”

“…In the flat Universe of Friedman, the widespread opinion about the prevalence of hidden energy over mass is rejected. The maximum possible fraction of hidden energy is 0.5 (Mahtessian et al, 2020).…”