Towards Precision Cosmology With Improved PNLF Distances Using VLT-MUSE II. A Test Sample from Archival Data

TL;DR

This study utilizes VLT-MUSE archival data to measure extragalactic distances via the planetary nebula luminosity function, deriving a Hubble Constant consistent with other methods, and discusses observational improvements for future precision cosmology.

Contribution

It demonstrates the feasibility of using archival VLT-MUSE data for PNLF distance measurements and provides insights into observational requirements for accurate H0 determination.

Findings

Robust PNLF distances obtained for 16 galaxies.

Derived Hubble Constant of 74.2 km/s/Mpc with uncertainties.

Identified observational needs to improve PNLF-based H0 measurements.

Abstract

Thanks to the MUSE integral field spectrograph on the VLT, extragalactic distance measurements with the [O III] 5007 A planetary nebula luminosity function (PNLF) are now possible out to approx. 40 Mpc. Here we analyze the VLT/MUSE data for 20 galaxies from the ESO public archive to identify the systems' planetary nebulae (PNe) and determine their PNLF distances. Three of the galaxies do not contain enough PNe for a robust measure of the PNLF, and the results for one other system are compromised by the galaxy's internal extinction. However, we obtain robust PNLF distances for the remaining 16 galaxies, two of which are isolated and beyond 30 Mpc in a relatively unperturbed Hubble flow. From these data, we derive a Hubble Constant of 74.2 +/- 7.2 (stat) +/-3.7 (sys) km/s/Mpc, a value that is very similar to that found from other quality indicators (e.g., Cepheids, the tip of the red giant branch, and surface brightness fluctuations). At present, the uncertainty is dominated by the small number of suitable galaxies in the ESO archival and their less than ideal observing conditions and calibrations. Based on our experience with these systems, we identify the observational requirements necessary for the PNLF to yield a competitive value for H0 that is independent of the SN Ia distance scale, and help resolve the current tension in the Hubble constant.