Median Statistics Estimate of the Distance to the Galactic Center

TL;DR

This paper analyzes 28 measurements of the distance to the Galactic center, finding non-Gaussian error distributions and proposing a median statistics estimate of 8.0 ± 0.3 kpc as the most reliable value.

Contribution

It introduces a median statistics approach to estimate the Galactic center distance, accounting for non-Gaussian error distributions in measurements.

Findings

Error distributions are wider than Gaussian, fitting an n=4 Student's t distribution.

Median estimate of R0 is 8.0 ± 0.3 kpc, likely the most reliable.

Results suggest non-Gaussian errors in astrophysical measurements.

Abstract

We show that error distributions of a compilation of 28 recent independent measurements of the distance from the Sun to the Galactic center, $R_{0}$, are wider than a standard Gaussian and best fit by an $n=4$ Student's $t$ probability density function. Given this non-Gaussianity, the results of our median statistics analysis, summarized as $R_{0}=8.0 \pm 0.3$ kpc ($2\sigma$ error), probably provides the most reliable estimate of $R_{0}$.