On the X-ray emission from massive star clusters and their evolving superbubbles II. Detailed analytics and observational effects

TL;DR

This paper develops detailed analytical models of X-ray emission from super star clusters and their superbubbles, incorporating effects like radiative cooling and metallicity, and compares these models with observational data.

Contribution

It introduces comprehensive analytical models for X-ray emission from superwinds and superbubbles, extending previous work with new effects and observational comparisons.

Findings

Models successfully reproduce observed X-ray luminosities.

Metallicity significantly influences X-ray emission properties.

Analytical surface brightness and temperature profiles match observational data.

Abstract

In this work, we present a comprehensive X-ray picture of the interaction between a super star cluster and the ISM. In order to do that, we compare and combine the X-ray emission from the superwind driven by the cluster with the emission from the wind-blown bubble. Detailed analytical models for the hydrodynamics and X-ray luminosity of fast polytropic superwinds are presented. The superwind X-ray luminosity models are an extension of the results obtained in Paper I of this series. Here, the superwind polytropic character allows to parameterize a wide variety of effects, for instance, radiative cooling. Additionally, X-ray properties that are valid for all bubble models taking thermal evaporation into account are derived. The final X-ray picture is obtained by calculating analytically the expected surface brightness and weighted temperature of each component. All of our X-ray models have an explicit dependence on metallicity and admit general emissivities as functions of the hydrodynamical variables. We consider a realistic X-ray emissivity that separates the contributions from hydrogen and metals. The paper ends with a comparison of the models with observational data.