A phenomenological model of galaxy clusters

TL;DR

This paper introduces a simple, parameterized phenomenological model for galaxy clusters that accurately reproduces observed dark matter, gas density, and temperature profiles using only five physically meaningful parameters.

Contribution

The model provides analytical expressions for cluster profiles with only five parameters, offering a straightforward way to interpret and analyze galaxy cluster observations.

Findings

Reproduces observed profiles within 20% accuracy

Uses only five physically meaningful parameters

Applicable to X-ray observed galaxy clusters

Abstract

We present a simple model to describe the dark matter density, the gas density, and the gas temperature profiles of galaxy clusters. Analytical expressions for these quantities are given in terms of only five free parameters with a clear physical meaning: the mass M of the dark matter halo (or the characteristic temperature T_0), the characteristic scale radius a, the cooling radius in units of a (0<alpha<1), the central temperature in units of T_0 (0<t<1), and the asymptotic baryon fraction in units of the cosmic value (f~1). It is shown that our model is able to reproduce the three-dimensional density and temperature profiles inferred from X-ray observations of real clusters within a 20 per cent accuracy over most of the radial range. Some possible applications are briefly discussed.