Statistical properties of the dark matter haloes of dwarf galaxies and correlations with the environment

TL;DR

This paper analyzes the structural properties of dark matter haloes in dwarf galaxies using observational data, exploring their correlations with environment to inform galaxy formation models.

Contribution

It provides observational constraints on dark matter halo parameters in dwarf galaxies and examines their relationship with environmental factors.

Findings

Constraints on halo density profile slopes and concentrations.

Evidence of correlations between halo properties and galaxy environment.

Insights into galaxy formation processes from halo-environment relationships.

Abstract

According to the now strongly supported concordance $\Lambda$CDM model, galaxies may be grossly described as a luminous component embedded in a dark matter halo. The density profile of these mass dominating haloes may be determined by N - body simulations which mimic the evolution of the tiny initial density perturbations during the process leading to the structures we observe today. Unfortunately, when the effect of baryons is taken into account, the situation gets much more complicated due to the difficulties in simulating their physics. As a consequence, a definitive prediction of how dark matter haloes should presently look like is still missing. We revisit here this issue from an observational point of view devoting our attention to dwarf galaxies. Being likely dark matter dominated, these systems are ideal candidates to investigate the present day halo density profiles and check whether dark matter related quantities correlate with the stellar ones or the environment. By fitting a large sample of well measured rotation curves, we infer constraints on both halo structural parameters (such as the logarithmic slope of the density profile and its concentration) and derived quantities (e.g., the mass fraction and the Newtonian acceleration) which could then be used to constrain galaxy formation scenarios. Moreover, we investigate whether the halo properties correlates with the environment the galaxy lives in thus offering a new tool to deepen our understanding of galaxy formation.