Mining the SPARC Galaxy Database: Finding "Hidden Variables" in the Baryonic Tully-Fisher Relation

TL;DR

This study refines the Baryonic Tully-Fisher Relation by incorporating individual galactic properties, challenging the necessity of a universal acceleration constant and revealing a family of galaxy-specific relations.

Contribution

It introduces a parametric form of the BTFR based on galactic properties, reducing reliance on the characteristic acceleration a0 and highlighting galaxy-specific variations.

Findings

A precise mass-velocity correlation can be achieved using galactic radius, mass discrepancy, and surface density.

No need to invoke a universal acceleration constant a0 for the BTFR.

The Radial Acceleration Relation (RAR) varies among galaxies, forming a family of curves rather than a single universal relation.

Abstract

The Baryonic Tully-Fisher Relation (BTFR) links baryonic mass of rotationally supported galaxies to their flat disk velocities. A popular form of the BTFR linked to MOND is based on an empirically determined characteristic acceleration, a0 that serves as the constant of proportionality. In this work, we propose an alternative, parametric form of the BTFR employing individual galactic properties from the SPARC galaxy database. Based on this data we find that a precise mass-velocity correlation is possible taking into account galactic disk radius and two dynamical related properties; mass discrepancy and disk surface density. We find no need to invoke a characteristic acceleration constant although its ansatz can be extracted and compared to several recent analyses also arguing against the MOND interpretation of a0. This improved BTFR finding has ramifications for the Radial Acceleration Relation (RAR) as well. Rather than a universal relation that describes the dynamics of all rotationally-supported galaxies, we find the RAR consists of a statistically distributed family of curves, reflecting the unique properties attributed to individual galaxies.