Using The Baryonic Tully-Fisher Relation to Measure $H_o$

TL;DR

This paper uses the baryonic Tully-Fisher relation as a new method to measure the Hubble constant, achieving a local value of approximately 75 km/s/Mpc with reduced uncertainties.

Contribution

It calibrates the baryonic Tully-Fisher relation with precise local galaxy distances and applies it to determine the Hubble constant independently of previous methods.

Findings

Measured H_o = 75.1 km/s/Mpc with ~3.2% total uncertainty.

Reduced scatter in bTFR due to improved imaging and models.

Demonstrated bTFR as a reliable distance indicator for cosmology.

Abstract

We explore the use of the baryonic Tully-Fisher relation (bTFR) as a new distance indicator. Advances in near-IR imaging and stellar population models, plus precise rotation curves, have reduced the scatter in the bTFR such that distance is the dominant source of uncertainty. Using 50 galaxies with accurate distances from Cepheids or tip magnitude of the red giant branch, we calibrate the bTFR on a scale independent of $H_o$. We then apply this calibrated bTFR to 95 independent galaxies from the SPARC sample, using CosmicFlows-3 velocities, to deduce the local value of $H_o$. We find $H_o$ = 75.1 +/- 2.3 (stat) +/- 1.5 (sys) km s$^{-1}$ Mpc$^{-1}$.