Weighing Cosmological Models with SNe Ia and GRB Redshift Data (original) (raw)
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Weighing Cosmological Models with SNe Ia and Gamma Ray Burst Redshift Data
Universe, 2019
Many models have been proposed to explain the intergalactic redshift using different observational data and different criteria for the goodness-of-fit of a model to the data. The purpose of this paper is to examine several suggested models using the same supernovae Ia data and gamma-ray burst (GRB) data with the same goodness-of-fit criterion and weigh them against the standard Lambda cold dark matter model (ΛCDM). We have used the redshift—distance modulus (z − μ) data for 580 supernovae Ia with 0.015 ≤ z ≤ 1.414 to determine the parameters for each model and then use these model parameter to see how each model fits the sole SNe Ia data at z = 1.914 and the GRB data up to z = 8.1. For the goodness-of-fit criterion, we have used the chi-square probability determined from the weighted least square sum through non-linear regression fit to the data relative to the values predicted by each model. We find that the standard ΛCDM model gives the highest chi-square probability in all cases ...
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The ESO Slice Project (ESP) is a galaxy redshift survey we have recently completed as an ESO Key-Project over about 23 square degrees, in a region near the South Galactic Pole. The survey is nearly complete to the limiting magnitude b J = 19.4 and consists of 3342 galaxies with reliable redshift determination.
Astronomy phenomenological analysis of redshift-distance power laws
Astrophysics and Space Science, 2000
The traditional astronomical literature accepts the linear redshift-distance law on the basis of its internal consistency with accepted models of the history of the universe more than on nontrivial clearly objective tests of the linear law for directly observed quantities. The reluctance to depend on such tests rested historically on the assumed large variation in the intrinsic luminosity of extragalactic objects and a distrust of curve-fitting and statistics. But such tests are eminently feasible on the basis of modern objectively specified samples and up-to-date statistical methodology. This paper compares red-shift distance relations of the form z = kr p , for real values of p. Data from the visible, infrared, radio, and X-ray bands are examined. The deviation of predicted and observed apparent magnitudes, (a), and the difference between observed and predicated slope of the magnitude-log(z) plots, (b), are used to compare values of p. In summary, the p = 1 values (corresponding to standard linear law) are more deviant than any other value of p, 1 < p <= 4 for test (a) and more deviant than any value of p, 1 < p <= 3 for test (b) except for marginal features in the smallest (radio) sample and in the lowest redshift sample. Bright subsamples and a morphologically homogeneous subsample of elliptic galaxies are also tested with similar results. In contrast, the predications for p = 2 are reasonably accurate and close to optimal among all values of p explored. The p = 2 case is predicted by the chronometric cosmology and in agreement with the independent analysis of Troitskii.
New derivation of redshift distance without using power expansions
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Here we use the flat Friedmann-Lemaitre-Robertson-Walker metric describing a spatially homogeneous and isotropic universe to derive the cosmological redshift distance in a way which differs from that which can be found in the astrophysical literature. We use the co-moving coordinate r_e (the subscript e indicates emission) for the place of a galaxy which is emitting photons and r_a (the subscript a indicates absorption) for the place of an observer within a different galaxy on which the photonswhich were traveling thru the universe-are absorbed. Therefore the real physical distance - the way of light - is calculated by D = a(t_0) r_a - a(t_e) r_e. Here means a(t_0) the today's (t_0) scale parameter and a(t_e) the scale parameter at the time of emission (t_e) of the photons. Nobody can doubt this real travel way of light: The photons are emitted on the co-moving coordinate place r_e and are than traveling to the co-moving coordinate place r_a. During this traveling the time is moving from t_e to t_0 (t_e ≤ t_0) and therefore the scale parameter is changing in the meantime from a(t_e) to a(t_0). Using this right way of light we calculate some relevant classical cosmological equations (effects) and compare these theoretical results with some measurements of astrophysics. As one result we get e.g. the today's Hubble parameter H_0a ≈ 62.34 km/(s Mpc). This value is smaller than the Hubble parameter H_0,Planck ≈ 67.66 km/(s Mpc) resulting from Planck 2018 data [12] which is discussed in the literature.
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Classical and Quantum Gravity, 2013
The beginning of the cosmological phase bearing the direct kinematic imprints of supernovae dimming may significantly vary within different models of late-time cosmology, even if such models are able to fit present SNe data at a comparable level of statistical accuracy. This effect-useful in principle to discriminate among different physical interpretations of the luminosity-redshift relation-is illustrated here with a pedagogical example based on the LTB geometry. * Such a configuration is in principle different from that of a typical "Swiss cheese" scenario, where the void regions are more or less regularly distributed and well disconnected (see e.g. [25]).
THE 2MASS REDSHIFT SURVEY—DESCRIPTION AND DATA RELEASE
The Astrophysical Journal Supplement Series, 2012
We present the results of the 2MASS Redshift Survey (2MRS), a ten-year project to map the full three-dimensional distribution of galaxies in the nearby Universe. The 2 Micron All-Sky Survey (2MASS) was completed in 2003 and its final data products, including an extended source catalog (XSC), are available on-line. The 2MASS XSC contains nearly a million galaxies with K s ≤ 13.5 mag and is essentially complete and mostly unaffected by interstellar extinction and stellar confusion down to a galactic latitude of |b| = 5 • for bright galaxies. Near-infrared wavelengths are sensitive to the old stellar populations that dominate galaxy masses, making 2MASS an excellent starting point to study the distribution of matter in the nearby Universe.
The Zurich Extragalactic Bayesian Redshift Analyzer and its first application: COSMOS
Monthly Notices of the Royal Astronomical Society, 2006
We present ZEBRA, the Zurich Extragalactic Bayesian Redshift Analyzer. The current version of ZEBRA combines and extends several of the classical approaches to produce accurate photometric redshifts down to faint magnitudes. In particular, ZEBRA uses the template-fitting approach to produce Maximum Likelihood and Bayesian redshift estimates based on: (1.) An automatic iterative technique to correct the original set of galaxy templates to best represent the SEDs of real galaxies at different redshifts; (2.) A training set of spectroscopic redshifts for a small fraction of the photometric sample to improve the robustness of the photometric redshift estimates; and (3.) An iterative technique for Bayesian redshift estimates, which extracts the full two-dimensional redshift and template probability function for each galaxy. We demonstrate the performance of ZEBRA by applying it to a sample of 866 I AB 22.5 COSMOS galaxies with available u * , B, V , g ′ , r ′ , i ′ , z ′ and K s photometry and zCOSMOS spectroscopic redshifts in the range 0 < z < 1.3. Adopting a 5-σ-clipping that excludes 10 galaxies, both the Maximum Likelihood and Bayesian ZEBRA estimates for this sample have an accuracy σ ∆z/(1+z) smaller than 0.03. Similar accuracies are recovered using mock galaxies. ZEBRA is made available to the public at: http://www.exp-astro.phys.ethz.ch/ZEBRA.
In this part of the two-part series of essays, we first derive some equations for further physical redshift distances. We then analyze a catalog with 132,975 quasars, for which both the apparent magnitude m and the redshift z are given, in order to find the today's value of the parameter β_0 of the theory presented. We then use this value to determine the today's value of the radius R_0a of the Friedmann sphere using a magnitude redshift diagram of 19 SNIa. With the help of the known values of R_0a and β_0 , statements about astrophysical data from the black hole in the galaxy M87 can be made. In addition, the today's Hubble parameter H_0 results from both parameters. Furthermore, we calculate the values of the further physical redshift distances for the black hole in M87 and all 19 SNIa. The resulting parameter values are: β_0 ≈ 0.731, R_0a ≈ 2,712.48 Mpc and H_0 ≈ 65.638 km / (s • Mpc). The today's mass density of the Friedmann sphere is ρ_0 ≈ 4.843 x 10-27 g / cm 3. For the mass of the Friedmann sphere we find M_FK ≈ 1.206 x 10+56 g. Annotation: Knowledge of the first part [1] of the series of articles is a prerequisite for understanding this article.
A simple direct empirical observation of systematic bias of the redshift as a distance indicator
Recent puzzling observations such as the \(H_o\) tension, large-scale anisotropies, and massive disk galaxies at high redshifts have been challenging the standard cosmological model. While one possible explanation is that the standard model is incomplete, other theories are based on the contention that the redshift model as a distance indicator might be biased. While these theories can explain the recent observations, they are challenged by the absence of a direct empirical reproducible observation that the redshift model can indeed be inconsistent. Here I describe a simple experiment that shows that the spectra of galaxies depend on their rotational velocity relative to the rotational velocity of the Milky Way. Moreover, it shows that the redshift of galaxies that rotate in the same direction relative to the Milky Way is significantly different from the redshift of galaxies that rotate in the opposite direction relative to the Milky Way (P\(<0.006\)). Three different datasets ar...