Estimation of the Mass of Dark Matter Using the Observed Mass Profiles of Late-Type Galaxies
arXiv:2102.09078 · doi:10.1088/1475-7516/2021/08/023
Abstract
The system of stability equations for galactic halos is under-determined in most of the models of dark matter (DM). Conventionally, the issue is resolved by taking the temperature as a constant, and the chemical potential and the mass density as position-dependent variables. In this paper, to close the under-determined set of equations, we remove the mass density using observations and leave the temperature and the chemical potential as position-dependent variables. We analyze observations of the mass profiles of 175 late-type galaxies in the Spitzer Photometry \& Accurate Rotation Curves (SPARC) database as well as 26 late-type dwarfs in the Little Things database, to construct the temperature profile of their DM halos by assuming that (1) DM in the halos obeys either the Fermi-Dirac or the Maxwell-Boltzmann distribution, and (2) the halos are in the virial state. We derive the dispersion velocity of DM at the center of the halos and show that its correlation with the halo's total mass is consistent with the direct observations of visible matter. Taking the latter agreement as a validation of our analysis, we derive the mass to the temperature of DM at the edge of the halos and show that it is galaxy independent and is equal to in natural units. In the thermal models of DM, such universal temperature is inherently assumed. In this paper, we derive the universal temperature from observations without imposing it by assumptions. Therefore, in the above ratio can be expressed in terms of the temperature of the cosmic microwave background (CMB) at the time of DM decoupling. This result is used to study possible cosmological scenarios. We show that observations are at odds with (1) non-thermal DM, (2) hot DM, and (3) collision-less cold DM. If DM is warm, we estimate its mass to be in the range of keV--MeV.
arXiv comment12 pages, 10 figures. Accepted for publication in JCAP
References in corpus (25)
- A Universal Density Profile from Hierarchical Clustering
- The Structure of Cold Dark Matter Halos
- Dark Matter Substructure in Galactic Halos
- Where are the missing galactic satellites?
- Too big to fail? The puzzling darkness of massive Milky Way subhaloes
- A universal angular momentum profile for galactic halos
- The Milky Way's bright satellites as an apparent failure of LCDM
- SPARC: Mass Models for 175 Disk Galaxies with Spitzer Photometry and Accurate Rotation Curves
- A Method for Measuring (Slopes of) the Mass Profiles of Dwarf Spheroidal Galaxies
- The Cores of Dwarf Galaxy Halos
- The Observed properties of Dark Matter on small spatial scales
- High-resolution mass models of dwarf galaxies from LITTLE THINGS
- A White Paper on keV Sterile Neutrino Dark Matter
- The distribution of dark matter in galaxies
- A comprehensive catalog of dark matter halo models for SPARC galaxies
- HeCS-SZ: The Hectospec Survey of Sunyaev-Zeldovich Selected Clusters
- Fermionic warm dark matter produces galaxy cores in the observed scales because of quantum mechanics
- Observational rotation curves and density profiles vs. the Thomas-Fermi galaxy structure theory
- On DDO154 and Cold Dark Matter halo profiles
- Dwarf spheroidal galaxies as degenerate gas of free fermions
- Measuring the Spin of Spiral Galaxies
- The mass distribution in Spirals
- Equation of state, universal profiles, scaling and macroscopic quantum effects in Warm Dark Matter galaxies
- The Dark Matter distribution function and Halo Thermalization from the Eddington equation in Galaxies
- On the Stability of Fermionic Non-Isothermal Dark Matter Halos