Extragalactic Planetary Nebulae (xPNe). Determining Distances out to 100 Mpc and the Renaissance of the PN Luminosity Function Method

TL;DR

This paper advocates for using extragalactic planetary nebulae and the PNLF method as an efficient, precise distance indicator to help resolve the H0 tension in cosmology, extending measurements out to 100 Mpc.

Contribution

It demonstrates that the PNLF method can be effectively used with new spectroscopic facilities to measure galaxy distances up to 100 Mpc, providing an independent estimate of H0.

Findings

PNLF can reach distances comparable to Cepheids with less telescope time

Wide-field spectroscopic facilities enable PNLF measurements out to 100 Mpc

PNLF offers an independent H0 estimate unaffected by supernova calibration

Abstract

The discrepancy of the Hubble parameter H0 as measured from the cosmic microwave background versus that found from traditional distance ladder measurements has produced considerable discussion about the need for another force in cosmology. However the significance of the discrepancy depends on understanding the systematic associated with crowding, metallicity effects, and extinction of the stellar tracers. Thus additional precision distance indicators in the local universe are desperately needed for investigating the H0 tension. The analysis of MUSE archival data makes the case that the Planetary Nebula Luminosity Function (PNLF) has become such an indicator, as the method can reach distances comparable to HST distances of Cepheid at a fraction of a cost, in terms of telescope time and ground-based. With new wide-field spectroscopic facilities it becomes possible to measure distances to early-type galaxies (ETGs) using the PNLF out to 100 Mpc distance, achieving a precise estimate for the H0 value which is independent of the Type Ia supernova calibration, with only single-epoch measurements.