Distance measurements to early-type galaxies by improving the fundamental plane

TL;DR

This study leverages SDSS DR15 data to derive the largest sample of fundamental plane distances for early-type galaxies, introducing improvements that significantly reduce measurement uncertainties and address systematic biases.

Contribution

The paper presents novel methods to enhance fundamental plane distance estimates by removing biases and expanding the model, resulting in more accurate galaxy distance measurements.

Findings

Reduced distance measurement uncertainty by about 50%.

Developed methods to correct systematic biases in the fundamental plane.

Provided a comprehensive galaxy group catalogue up to redshift 0.5.

Abstract

Using SDSS DR15 to its full extent, we derived fundamental plane distances to over 317 000 early-type galaxies up to a redshift of 0.4. In addition to providing the largest sample of fundamental plane distances ever calculated, as well as a well calibrated group catalogue covering the entire SDSS spectroscopic footprint as far a redshift of 0.5, we present several improvements reaching beyond the traditional definition of the fundamental plane. In one approach, we adjusted the distances by removing systematic biases and selection effects in redshift-magnitude space, thereby greatly improving the quality of measurements. Alternatively, by expanding the traditional fundamental plane by additional terms, we managed to remove systematic biases caused by the selection of our SDSS spectroscopic galaxy sample as well as notably reducing its scatter. We discuss the advantages and caveats of these various methods and calibrations in detail. We found that improving the fundamental plane distance estimates beyond the established methods requires a delicate balancing act between various systematic biases and gains, but managed to reduce the uncertainty of our distance measurements by about a factor of two compared to the traditional fundamental plane.