# Modelling the SPARC galaxies using neo-MOND scaling relationships: the determination of distance scales and masses purely from disk dynamical data

## TL;DR

This paper applies the neo-MOND model to the SPARC galaxy sample to derive galaxy distances and masses solely from rotation curves and photometry, providing a new approach to galaxy scaling relations.

## Contribution

It introduces neo-MOND as a theoretical framework that derives galaxy distances and masses directly from disk dynamical data, extending classical MOND with a more fundamental basis.

## Key findings

- Neo-MOND accurately reproduces the baryonic Tully-Fisher relation.
- It independently determines absolute galaxy distances without standard candles.
- Dynamical mass estimates from neo-MOND match photometric masses across the sample.

## Abstract

The SPARC sample consists of 175 nearby galaxies with modern surface photometry at $3.6\,\mu m$ and high quality rotation curves. The sample has been constructed to span very wide ranges in surface brightness, luminosity, rotation velocity and Hubble type, thereby forming a representative sample on galaxies in the nearby Universe. To date, the SPARC sample is the largest collection of galaxies with both high-quality rotation curves and NIR surface photometry. The neo-MOND model used here to analyse the SPARC sample recognizably conforms to the general pattern of the classical MOND algorithm, with the primary difference that, whereas the classical MOND model is purely phenomonological, the neo-MOND model is a special case of a general theory motivated by the ideas of Leibniz and Mach (not discussed here). The consequent main results can be broadly summarized as follows: (1) neo-MOND provides the basis for the derivation of a complete theory of the baryonic Tully-Fisher relation; (2) the details of the derivation provide a means of setting absolute distance scales for disc galaxies independently of standard candles and the photometric method; (3) subsequent determinations of dynamical mass (computed directly from neo-MOND fits to SPARC rotation curves) track photometric mass (estimated from SPARC surface photometry) across the whole SPARC sample in a statistically perfect way. To summarize, if the input to neo-MOND is disk dynamical data, then the output is whole-disk mass data together with absolute distance scales.