Dark matter profile in clusters of galaxies

Neto, L. P. de Souza; Gastão, B

doi:10.1590/s0103-97332005000700042

Cited by 3 publications

(3 citation statements)

References 20 publications

(25 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As follows from (Neto 2005;Vikhlinin et al 2006;Einasto 2011), the density of gas comprising atomic and molecular hydrogen can be described using the Navarro-Frenk-White profile:…”

Section: Methodsmentioning

confidence: 99%

Moment of Inertia of Gas as a Source of Added Gravitational Field in Galaxies

Portnov¹

2022

Journal of Astronomy and Space Sciences

View full text Add to dashboard Cite

In this paper we propose a new perspective for explaining galaxy rotation curves. We conjecture that there is a gravitational moment of inertia which, together with gravitational mass, contributes to the gravitational potential. We substantiate a formula for the potential created by the moment of inertia. We validate our model by computing orbital rotation velocities for several galaxies and showing that computed rotation velocities correspond to the observed ones. Our proposed approach is capable of accounting for constant gas velocities outside of a galactic disc without relying on the dark matter hypothesis. Furthermore, it addresses several problems faced by the application of the dark matter hypothesis, e.g., the absence of inward collapse of dark matter into a galaxy, the spherical distribution of dark matter around galaxies, and absence of traces of the effect of dark matter in two ultra-diffuse galaxies, NGC 1052-DF2, and NGC 1052-DF4.

show abstract

“…As follows from (Neto 2005;Vikhlinin et al 2006;Einasto 2011), the density of gas comprising atomic and molecular hydrogen can be described using the Navarro-Frenk-White profile:…”

Section: Methodsmentioning

confidence: 99%

Moment of Inertia of Gas as a Source of Added Gravitational Field in Galaxies

Portnov¹

2022

Journal of Astronomy and Space Sciences

View full text Add to dashboard Cite

show abstract

“…The baryonic -stellar and gaseous-matter contained in galaxies and in the form of intracluster Xray emitting hot gas (intracluster medium, ICM, e.g., Böhringer & Werner 2010) is estimated (White 1992;Lima-Neto et al 2005) to account for only 15% of the total mass of a galaxy system, while the remaining 85% is provided by the dark matter (DM). Nevertheless, as a first approximation, one can consider a group/cluster as a collisionless ensemble of galaxies moving in the mean gravitational field generated by its total mass (e.g., Schneider 2015).…”

mentioning

confidence: 99%

“…Of course, the parameters associated with the global dynamics of the system also change in the process, and may be useful for the estimation of state functions such as entropy. No assumption is made here about the distribution of DM and ICM within the cluster ( Lokas & Mamon 2003;Lima-Neto et al 2005), but only about their important contribution to the total gravitational potential that determines the dynamics of the galaxy ensemble.…”

mentioning

confidence: 99%

Testing an Entropy Estimator Related to the Dynamical State of Galaxy Clusters

Zúñiga,

Caretta,

González

et al. 2024

RMxAA

View full text Add to dashboard Cite

We propose the entropy estimator HZ, calculated from global dynamical parameters, in an attempt to capture the degree of evolution of galaxy systems. We assume that the observed (spatial and velocity) distributions of member galaxies in these systems evolve over time towards states of higher dynamical relaxation (higher entropy), becoming more random and homogeneous in virial equilibrium. Thus, the HZ-entropy should correspond to the gravitacional assembly state of the systems. This was probed in a sample of 70 well sampled clusters in the Local Universe whose gravitational assembly state, classified from optical and X-ray analysis of substructures, shows clear statistical correlation with HZ. This estimator was also tested on a sample of clusters (halos) from the IllustrisTNG simulations, obtaining results in agreement with the observational ones.

show abstract

High-energy neutrino production in clusters of galaxies

Hussain

Batista

Pino

et al. 2021

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Clusters of galaxies can potentially produce cosmic rays (CRs) up to very-high energies via large-scale shocks and turbulent acceleration. Due to their unique magnetic-field configuration, CRs with energy ≤1017 eV can be trapped within these structures over cosmological time scales, and generate secondary particles, including neutrinos and gamma rays, through interactions with the background gas and photons. In this work we compute the contribution from clusters of galaxies to the diffuse neutrino background. We employ three-dimensional cosmological magnetohydrodynamical simulations of structure formation to model the turbulent intergalactic medium. We use the distribution of clusters within this cosmological volume to extract the properties of this population, including mass, magnetic field, temperature, and density. We propagate CRs in this environment using multi-dimensional Monte Carlo simulations across different redshifts (from z ∼ 5 to z = 0), considering all relevant photohadronic, photonuclear, and hadronuclear interaction processes. We find that, for CRs injected with a spectral index α = 1.5 − 2.7 and cutoff energy Emax = 1016 − 5 × 1017 eV, clusters contribute to a sizeable fraction to the diffuse flux observed by the IceCube Neutrino Observatory, but most of the contribution comes from clusters with M ≳ 1014 M⊙ and redshift z ≲ 0.3. If we include the cosmological evolution of the CR sources, this flux can be even higher.

show abstract

Dark matter profile in clusters of galaxies

Cited by 3 publications

References 20 publications

Moment of Inertia of Gas as a Source of Added Gravitational Field in Galaxies

Moment of Inertia of Gas as a Source of Added Gravitational Field in Galaxies

Testing an Entropy Estimator Related to the Dynamical State of Galaxy Clusters

High-energy neutrino production in clusters of galaxies

Contact Info

Product

Resources

About