GHASP: an H$\alpha$ kinematical survey of spiral galaxies - XI. Distribution of luminous and dark matter in spiral and irregular nearby galaxies using WISE photometry

TL;DR

This study analyzes the distribution of luminous and dark matter in 121 nearby galaxies of all types using combined optical kinematic data and WISE infrared photometry, revealing that core dark matter profiles fit better than cuspy ones and that dark matter distribution depends on galaxy morphology.

Contribution

It provides a comprehensive analysis of dark and luminous matter distribution across all galaxy types using combined kinematic and infrared data, with insights into the influence of morphology.

Findings

Most galaxy rotation curves are better fitted with core profiles.

Dark matter distribution depends on galaxy morphology and bulge presence.

Maximum disc models suggest discs are often maximal.

Abstract

We present the mass distribution of a sample of 121 nearby galaxies with high quality optical velocity fields and available infra-red $\it{WISE}$ 3.4 $\mu$m data. Contrary to previous studies, this sample covers all morphological types and is not biased toward late-type galaxies. These galaxies are part of the Fabry-Perot kinematical $\it{GHASP}$ survey of spirals and irregular nearby galaxies. Combining the kinematical data to the $\it{WISE}$ surface brightness data probing the emission from the old stellar population, we derive mass models allowing us to compare the luminous to the dark matter halo mass distribution in the optical regions of those galaxies. Dark matter (DM) models are constructed using the isothermal core profile and the Navarro-Frenk-White cuspy profile. We allow the M/L of the baryonic disc to vary or we keep it fixed, constrained by stellar evolutionary models (WISE W$_1$-W$_2$ color) and we carry out best fit (BFM) and pseudo-isothermal maximum disc (MDM) models. We found that the MDM provides M/L values four times higher than the BFM, suggesting that disc components, on average, tend to be maximal. The main results are: (i) the rotation curves of most galaxies are better fitted with core rather than cuspy profiles; (ii) the relation between the parameters of the DM and of the luminous matter components mostly depends on morphological types. More precisely, the distribution of the DM inside galaxies depends on whether or not the galaxy has a bulge.