Global disk model for galaxies NGC 1365, NGC 6946, NGC 7793, UGC 6446

TL;DR

This paper introduces a simple global disc model to estimate mass profiles of spiral galaxies using rotation curves and gas data, providing results consistent with observations and offering an alternative to dark matter halo assumptions.

Contribution

The study presents a global disc model for galaxies that reliably estimates mass profiles without assuming non-baryonic dark matter halos, improving upon previous methods.

Findings

Mass-to-light ratio profiles derived from the model.

Consistent surface mass densities with observed data.

Application to multiple galaxies including NGC 1365 and UGC 6446.

Abstract

Spiral galaxies are studied using a simple global disc model as a means for approximate determination of mass profiles. Based on rotation curves and the amount of gas (HI+He), we find global surface mass densities consistent with measurements and compare them with B-band surface brightness profiles. As a result we obtain mass-to-light ratio profiles. We give some arguments for why our approach is reliable and sometimes better than those assuming ad hoc the presence of a massive non-baryonic dark matter halo. Using this model, we study galaxies NGC 7793, 1365, 6946 and UGC 6446. Based on a rotation curve from The HI Nearby Galaxy Survey (THINGS) we also study galaxy NGC 4536 and compare the results with those we published elsewhere for the same galaxy.