Towards Precision Cosmology With Improved PNLF Distances Using VLT-MUSE I. Methodology and Tests

TL;DR

This paper introduces a novel DELF technique using MUSE data to improve the accuracy and sensitivity of PNLF distance measurements, enabling precise galaxy distances beyond traditional methods and aiding cosmological parameter estimation.

Contribution

It develops and validates a differential emission-line filter method with adaptive optics for enhanced PNLF distance measurements using MUSE data.

Findings

DELF outperforms classical methods in high surface brightness regions.

Capable of measuring <0.05 mag photometry out to 40 Mpc.

Enables PNLF distances beyond Cepheids and red giant branch methods.

Abstract

The [O III ] 5007 Planetary Nebula Luminosity Function (PNLF) is an established distance indicator that has been used for more than 30 years to measure the distances of galaxies out to ~15 Mpc. With the advent of the Multi-Unit Spectroscopic Explorer on the Very Large Telescope (MUSE) as an efficient wide-field integral field spectrograph, the PNLF method is due for a renaissance, as the spatial and spectral information contained in the instrument's datacubes provides many advantages over classical narrow-band imaging. Here we use archival MUSE data to explore the potential of a novel differential emission-line filter (DELF) technique to produce spectrophotometry that is more accurate and more sensitive than other methods. We show that DELF analyses are superior to classical techniques in high surface brightness regions of galaxies and we validate the method both through simulations and via the analysis of data from two early-type galaxies (NGC 1380 and NGC 474) and one late-type spiral (NGC 628). We demonstrate that with adaptive optics support or under excellent seeing conditions, the technique is capable of producing precision (< 0.05 mag) [O III ] photometry out to distances of 40 Mpc while providing discrimination between planetary nebulae and other emission-line objects such as H II regions, supernova remnants, and background galaxies. These capabilities enable us to use MUSE to measure precise PNLF distances beyond the reach of Cepheids and the tip of the red giant branch method, and become an additional tool for constraining the local value of the Hubble constant.