Derivation of Distances with the Tully-Fisher Relation: The Antlia Cluster

TL;DR

This paper discusses using the Tully-Fisher relation to measure distances to galaxies in the Antlia Cluster, emphasizing selection criteria to avoid biases and improve accuracy in distance estimation.

Contribution

It introduces specific selection criteria for galaxies in clusters to accurately derive distances using the Tully-Fisher relation, minimizing biases and systematic errors.

Findings

Cluster distance derived from multiple galaxies reduces error by sqrt(N)

Selection criteria prevent Malmquist bias in distance measurements

Method improves accuracy of Tully-Fisher based distances

Abstract

The Tully-Fisher relation is a correlation between the luminosity and the HI 21cm line width in spiral galaxies (LLW relation). It is used to derive galaxy distances in the interval 7 to 100 Mpc. Closer, the Cepheids, TRGB and Surface Brightness Fluctuation methods give a better accuracy. Further, the SNIa are luminous objects still available for distance measurement purposes, though with a dramatically lower density grid of measurements on the sky. Galaxies in clusters are all at the same distance from the observer. Thus the distance of the cluster derived from a large number of galaxies (N) has an error reduced according to the square root of N. However, not all galaxies in a cluster are suitable for the LLW measurement. The selection criteria we use are explained hereafter; the important point being to avoid Malmquist bias and to not introduce any systematics in the distance measurement.