Median Statistics Estimate of the Distance to M87

Abstract

de Grijs and Bono compiled 211 independent measurements of the distance to galaxy M87 in the Virgo cluster from 15 different tracers and reported the arithmetic mean of a subset of this compilation as the best estimate of the distance. We compute three different central estimates -- the arithmetic mean, weighted mean, and the median -- and corresponding statistical uncertainty for the full data set as well as two sub-compilations. We find that for all three central estimates the error distributions show that the data sets are significantly non-Gaussian. As a result, we conclude that that the median is the most reliable of the three central estimates, as median statistics does not assume Gaussianity. We use median statistics to determine the systematic error on the distance by analyzing the scatter in the 15 tracer subgroup distances. From the 211 distance measurements, we recommend a summary M87 distance modulus of $31.08_{-0.05}^{+0.04}$ (statistical) ${}_{-0.06}^{+0.04}$ (systematic) mag, or combining the two errors in quadrature $31.08_{-0.08}^{+0.06}$ mag, rounded to $16.4_{-0.6}^{+0.5}$ Mpc, all at $68.27\%$ significance.

7 Pages, 2 Tables, Accepted in PASP (PASP-101639.R1)

References in corpus (10)

• Clustering of Local Group distances: publication bias or correlated measurements? I. The Large Magellanic Cloud
• Clustering of Local Group distances: publication bias or correlated measurements? IV. The Galactic Center
• Not Normal: the uncertainties of scientific measurements
• Median Statistics Estimate of the Distance to the Galactic Center
• A New Estimate of the Best Value for the Solar Galactocentric Distance
• Median statistics estimates of Hubble and Newton's Constant
• Clustering of Local Group distances: publication bias or correlated measurements? V. Galactic rotation constants
• MFV approach to robust estimate of neutron lifetime
• Clustering of Local Group distances: publication bias or correlated measurements? VI. Extending to Virgo cluster distances
• A meta-analysis of distance measurements to M87

Cited by in corpus (1)

• Distance to M87 as the Mode of the Modulus Distribution