Optimal Galaxy Distance Estimators
Abstract
The statistical properties of galaxy distance estimators corresponding to the TullyFisher and D_n_σ relations are studied, and a rigorous framework for identifying and removing the effects of Malmquist bias due to observational selection is developed. The prescription of Schechter for defining unbiased distance estimators is verified and extended to more generaland more realistic  cases. Finally, the derivation of "optimal" unbiased estimators of minimum dispersion, by utilizing information from additional suitably correlated observables, is discussed and the results applied to a calibrating sample from the Fornax cluster, as used in the Mathewson spiral galaxy redshift survey. In this illustrative example the optimal distance estimator derived from apparent magnitude, isophotal diameter, and line width has an intrinsic scatter which is ~22% smaller than that of the conventional TullyFisher relation.
 Publication:

The Astrophysical Journal
 Pub Date:
 November 1994
 DOI:
 10.1086/174832
 arXiv:
 arXiv:astroph/9310029
 Bibcode:
 1994ApJ...435..515H
 Keywords:

 Distance;
 Galaxies;
 Mathematical Models;
 Spatial Distribution;
 Three Body Problem;
 Red Shift;
 Statistical Analysis;
 Three Dimensional Motion;
 Time Dependence;
 Astrophysics;
 COSMOLOGY: DISTANCE SCALE;
 COSMOLOGY: LARGESCALE STRUCTURE OF UNIVERSE;
 GALAXIES: DISTANCES AND REDSHIFTS;
 METHODS: STATISTICAL;
 Astrophysics
 EPrint:
 Plain Latex, 19 pages, SussexAST93/92