Intrinsic Redshifts and the TullyFisher Distance Scale
Author: Russell, David
Source: Astrophysics and Space Science, Volume 299, Number 4, October 2005 , pp. 405-418(14)
Abstract:The TullyFisher relationship (TFR) has been shown to have a relatively small observed scatter of ±0.35 mag implying an intrinsic scatter < ±0.30 mag. However, when the TFR is calibrated from distances derived from the Hubble relation for field galaxies scatter is consistently found to be ±0.64 to ±0.84 mag. This significantly larger scatter requires that intrinsic TFR scatter is actually much larger than ±0.30 mag, that field galaxies have an intrinsic TFR scatter much larger than cluster spirals, or that field galaxies have a velocity dispersion relative to the Hubble flow in excess of 1000 km s-1. Each of these potential explanations faces difficulties and contradicted by available data and the results of previous studies. An alternative explanation is that the measured redshifts of galaxies are composed of a cosmological redshift component predicted from the value of the Hubble constant and a superimposed intrinsic redshift component previously identified in other studies. This intrinsic redshift component may exceed 5000 km s-1 in individual galaxies. In this alternative scenario a possible value for the Hubble constant is 5560 km s-1 Mpc-1.
Document Type: Research article
Publication date: 2005-10-01