Comparison of Models for the Warm-Hot Circumgalactic Medium around Milky Way-like Galaxies

Fuente: arXiv
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Auteurs principaux: Singh, Priyanka, Lau, Erwin T., Faerman, Yakov, Stern, Jonathan, Nagai, Daisuke
Format: Preprint
Publié: 2024
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author Singh, Priyanka
Lau, Erwin T.
Faerman, Yakov
Stern, Jonathan
Nagai, Daisuke
author_facet Singh, Priyanka
Lau, Erwin T.
Faerman, Yakov
Stern, Jonathan
Nagai, Daisuke
contents A systematic comparison of the models of the circumgalactic medium (CGM) and their observables is crucial to understanding the predictive power of the models and constraining physical processes that affect the thermodynamics of CGM. This paper compares four analytic CGM models: precipitation, isentropic, cooling flow, and baryon pasting models for the hot, volume-filling CGM phase, all assuming hydrostatic or quasi-hydrostatic equilibrium. We show that for fiducial parameters of the CGM of a Milky-Way (MW) like galaxy ($\rm M_{vir} \sim 10^{12}~M_{\odot}$ at $z\sim 0$), the thermodynamic profiles -- entropy, density, temperature, and pressure -- show most significant differences between different models at small ($r\lesssim 30$ kpc) and large scales ($r\gtrsim 100$ kpc) while converging at intermediate scales. The slope of the entropy profile, which is one of the most important differentiators between models, is $\approx 0.8$ for the precipitation and cooling flow models, while it is $\approx0.6$ and 0 for the baryon pasting and isentropic models, respectively. We make predictions for various observational quantities for an MW mass halo for the different models, including the projected Sunyaev-Zeldovich (SZ) effect, soft X-ray emission (0.5--2 keV), dispersion measure, and column densities of oxygen ions (OVI, OVII, and OVIII) observable in absorption.
format Preprint
id arxiv_https___arxiv_org_abs_2407_06555
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Comparison of Models for the Warm-Hot Circumgalactic Medium around Milky Way-like Galaxies
Singh, Priyanka
Lau, Erwin T.
Faerman, Yakov
Stern, Jonathan
Nagai, Daisuke
Astrophysics of Galaxies
A systematic comparison of the models of the circumgalactic medium (CGM) and their observables is crucial to understanding the predictive power of the models and constraining physical processes that affect the thermodynamics of CGM. This paper compares four analytic CGM models: precipitation, isentropic, cooling flow, and baryon pasting models for the hot, volume-filling CGM phase, all assuming hydrostatic or quasi-hydrostatic equilibrium. We show that for fiducial parameters of the CGM of a Milky-Way (MW) like galaxy ($\rm M_{vir} \sim 10^{12}~M_{\odot}$ at $z\sim 0$), the thermodynamic profiles -- entropy, density, temperature, and pressure -- show most significant differences between different models at small ($r\lesssim 30$ kpc) and large scales ($r\gtrsim 100$ kpc) while converging at intermediate scales. The slope of the entropy profile, which is one of the most important differentiators between models, is $\approx 0.8$ for the precipitation and cooling flow models, while it is $\approx0.6$ and 0 for the baryon pasting and isentropic models, respectively. We make predictions for various observational quantities for an MW mass halo for the different models, including the projected Sunyaev-Zeldovich (SZ) effect, soft X-ray emission (0.5--2 keV), dispersion measure, and column densities of oxygen ions (OVI, OVII, and OVIII) observable in absorption.
title Comparison of Models for the Warm-Hot Circumgalactic Medium around Milky Way-like Galaxies
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2407.06555