A case for H0 = 42 and Omega(0) = 1 using luminous spiral galaxies and the cosmological time scale test

Abstract

view Abstract Citations (56) References (104) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Case for H 0 = 42 and Omega 0 = 1 Using Luminous Spiral Galaxies and the Cosmological Time Scale Test Sandage, Allan Abstract There are two internally self-consistent methods of finding the Hubble velocity-distance ratios for individual galaxies. In the first, one assumes a linear velocity-distance relation, from which relative distances are found from the velocities. A system of absolute magnitudes is obtained thereby, later zero-pointed using Cepheid distances to local calibrating galaxies. In the second, one uses some parameter such as 21 cm line width, or the internal velocity dispersion, or the de Vaucouleurs {LAMBDA}-index, etc., to which is assigned a fixed absolute magnitude <M> for each value of the parameter, again zero-pointed later from the Cepheid calibrating galaxies. Neither of the two methods can be faulted by considering only the internal data of a flux-limited sample, yet one or the other gives the wrong mean Hubble constant unless external information is known, either on the form of the velocity field (i.e., whether the redshift-distance relation is linear), or on the dispersion of the luminosity function. The self-consistency can be broken by adding data from a fainter flux-limited sample, seeking a contradiction in one of the methods. The test of which method is in error, and therefore whether the high or low value of H_0_ is correct, is made here by combining redshift and magnitude data for bright ScI galaxies from the RSA with faint ScI galaxies from two catalogs in the literature to demonstrate the bias in the second method directly. It is shown that the method of assigning a fixed <M> to each ScI galaxy in the bright sample (or to any other parameter that might be adopted as a distance indicator) produces an artificially compressed distance scale, imitating a varying Hubble ratio that appears to increase outward. However, adding the bright and faint samples gives a list that approaches a volume-limited catalog for redshifts smaller than ~4000 km s^-1^, from which it is demonstrated that (1) the local velocity-distance relation is linear over this redshift range (2), the ScI luminosity function is broad with σ<M> = 0.7 mag, and (3) the value of the Hubble constant is low. Calibration of the ScI magnitude and redshift data in the v approaches 0 limit, using M31, M81, and M101 as calibrators, gives Publication: The Astrophysical Journal Pub Date: August 1988 DOI: 10.1086/166584 Bibcode: 1988ApJ...331..583S Keywords: Cosmology; Globular Clusters; Hubble Constant; Spiral Galaxies; Time Measurement; Bias; Brightness Distribution; Color-Magnitude Diagram; Distance; Monte Carlo Method; Red Shift; Astrophysics; COSMOLOGY; GALAXIES: DISTANCES full text sources ADS | data products SIMBAD (209) NED (207)