Baryonic distributions in galaxy dark matter haloes – II. Final results

Abstract

Re-creating the observed diversity in the organization of baryonic mass within dark matter haloes represents a key challenge for galaxy formation models. To address the growth of galaxy discs in dark matter haloes, we have constrained the distribution of baryonic and non-baryonic matter in a statistically representative sample of 44 nearby galaxies defined from the Extended Disk Galaxy Exploration Science (EDGES) Survey. The gravitational potentials of each galaxy are traced using rotation curves derived from new and archival radio synthesis observations of neutral hydrogen (H I). The measured rotation curves are decomposed into baryonic and dark matter halo components using 3.6 µm images for the stellar content, the H I observations for the atomic gas component, and, when available, CO data from the literature for the molecular gas component. The H I kinematics are supplemented with optical integral field spectroscopic (IFS) observations to measure the central ionized gas kinematics in 26 galaxies, including 13 galaxies that are presented for the first time in this paper. Distributions of baryonic-to-total mass ratios are determined from the rotation curve decompositions under different assumptions about the contribution of the stellar component and are compared to global and radial properties of the dominant stellar populations extracted from optical and near-infrared photometry. Galaxies are grouped into clusters of similar baryonic-to-total mass distributions to examine whether they also exhibit similar star and gas properties. The radial distribution of baryonic-to-total mass in a galaxy does not appear to correlate with any characteristics of its star formation history.

GHASP: an H α kinematical survey of spiral galaxies – XI. Distribution of luminous and dark matter in spiral and irregular nearby galaxies using WISE photometry

“…These values are consistent with Lelli et al (2016) who found M/L minimum and maximum values of ∼ 0.2 and ∼0.7 M /L respectively. The median value of the fixed M/L (0.5 M /L ) is similar to the fixed M/L assumed by Lelli et al (2016) and Richards et al (2018), who used 3.6 µm photometric data. The M/L value obtained using the MDM model is ∼4 times higher than the value of the BFM.…”

Ejection of supermassive black holes and implications for merger rates in fuzzy dark matter haloes

“…The decomposition of disk galaxies into bulge, disk and halo components is complex, and can lead to radically different results depending on assumptions, particularly regarding the mass-to-light ratios (e.g., Sofue 2016;Richards et al 2018). It is however unlikely that a three-dimensional baryonic component dominates most disk galaxies at scales larger than ∼ kpc.…”

The GMRT archive atomic gas survey -- I. Survey definition, methodology, and initial results from the pilot sample

“…Further Patsis et al (2009) used the findings of Boonyasait et al (2005) and studied the stellar and gas dynamics for this galaxy. Richards et al (2018b) in their study of the baryonic distributions in galaxy dark matter halo, observed NGC4068 through VLA-C configuration with velocity resolution 0.825 kms −1 . Wilcots et al (1996) and Thuan et al (2004) observed NGC4861 using VLA-D and VLA-C configuration with channel resolution 5.2 kms −1 and 2.6 kms −1 respectively and sensitivity ∼ 1 mJy/beam for both cases.…”

“…Furthermore, the HI cubes with its 3D kinematic modeling done with the recently developed tools to fit the tilted ring model (Rogstad et al 1974) by Józsa et al (2007) and Di Teodoro & Fraternali (2015) gives us the detailed kinematics and dynamics of the galaxies. The rotation curve, when combined with optical or infrared observation, provides the mass model of the galaxies, i.e., the radial distribution of different components (star, gas and the dark matter) of galaxies and the scope to test different dark matter halo profiles (see Richards et al 2018a;Kurapati et al 2018bKurapati et al , 2020. The interferometric cubes are also helpful to find the 3D distribution of the atomic gas and its volumetric properties.…”