The Distance to NGC 5128 (Centaurus A)

TL;DR

This paper reviews multiple high-precision methods for measuring the distance to NGC 5128, concluding with a well-supported estimate of 3.8 Mpc, and discusses its significance for the extragalactic distance scale.

Contribution

It provides a comprehensive evaluation of various distance measurement techniques applied to NGC 5128 and establishes a refined distance estimate supported by current data.

Findings

Estimated distance to NGC 5128 is 3.8 ± 0.1 Mpc.

Multiple methods agree within uncertainties.

NGC 5128 serves as a key testbed for distance scale calibration.

Abstract

In this paper we review the various high precision methods that are now available to determine the distance to NGC 5128. These methods include: Cepheids, TRGB (tip of the red giant branch), PNLF (planetary nebula luminosity function), SBF (surface brightness fluctuations) and Long Period Variable (LPV) Mira stars. From an evaluation of these methods and their uncertainties, we derive a best-estimate distance of 3.8 +- 0.1 Mpc to NGC 5128 and find that this mean is now well supported by the current data. We also discuss the role of NGC 5128 more generally for the extragalactic distance scale as a testbed for the most direct possible comparison among these key methods.