Cosmic Ray Mediated Thermal Fronts in the Warm-Hot Circumgalactic Medium

Fuente: arXiv
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Main Authors: Zhu, Hanjue, Zweibel, Ellen G., Gnedin, Nickolay Y.
Format: Preprint
Published: 2024
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author Zhu, Hanjue
Zweibel, Ellen G.
Gnedin, Nickolay Y.
author_facet Zhu, Hanjue
Zweibel, Ellen G.
Gnedin, Nickolay Y.
contents We investigate the 1D plane-parallel front connecting the warm ($10^4$ K) and hot ($10^6$ K) phases of the circumgalactic medium (CGM), focusing on the influence of cosmic rays (CRs) in shaping these transition layers. We find that cosmic rays dictate the thermal balance while other fluxes (thermal conduction, radiative cooling, and gas flow) adjust to compensate. We compute column density ratios for selected transition temperature ions and compare them with observational data. While most of our models fail to reproduce the observations, a few are successful, although we make no claims for their uniqueness. Some of the discrepancies may indicate challenges in capturing the profiles in cooler, photoionized regions, as has been suggested for by previous efforts to model thermal transition layers.
format Preprint
id arxiv_https___arxiv_org_abs_2410_17252
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Cosmic Ray Mediated Thermal Fronts in the Warm-Hot Circumgalactic Medium
Zhu, Hanjue
Zweibel, Ellen G.
Gnedin, Nickolay Y.
High Energy Astrophysical Phenomena
Astrophysics of Galaxies
We investigate the 1D plane-parallel front connecting the warm ($10^4$ K) and hot ($10^6$ K) phases of the circumgalactic medium (CGM), focusing on the influence of cosmic rays (CRs) in shaping these transition layers. We find that cosmic rays dictate the thermal balance while other fluxes (thermal conduction, radiative cooling, and gas flow) adjust to compensate. We compute column density ratios for selected transition temperature ions and compare them with observational data. While most of our models fail to reproduce the observations, a few are successful, although we make no claims for their uniqueness. Some of the discrepancies may indicate challenges in capturing the profiles in cooler, photoionized regions, as has been suggested for by previous efforts to model thermal transition layers.
title Cosmic Ray Mediated Thermal Fronts in the Warm-Hot Circumgalactic Medium
topic High Energy Astrophysical Phenomena
Astrophysics of Galaxies
url https://arxiv.org/abs/2410.17252