Deviations from hydrostatic equilibrium in the circumgalactic medium: spinning hot haloes and accelerating flows

Abstract

Hydrostatic equilibrium (HSE), where the thermal pressure gradient balances the force of gravity, is tested across a range of simulated EAGLE haloes from Milky Way L* haloes (M_200~10^12 Msol) to cluster scales. Clusters (M_200>=10^14 Msol) reproduce previous results with thermal pressure responsible for ~90% of the support against gravity, but this fraction drops for group-sized haloes (M_200~10^13 Msol) and is even lower (40-70%) for L* haloes between 0.1-0.3 R_200. Energy from feedback grows relative to the binding energy of a halo toward lower mass resulting in greater deviations from HSE. Tangential motions comprise the largest deviation from HSE in L* haloes indicating that the hot circumgalactic medium (CGM) has significant sub- centrifugal rotation and angular momentum spin parameters 2-3x higher than the dark matter spin parameters. Thermal feedback can buoyantly rise to the outer CGM of M_200<10^12 Msol haloes, both moving baryons beyond R_200 and feeding uncorrelated tangential motions. The resulting hot halo density and rotation profiles show promising agreement with X-ray observations of the inner Milky Way halo, and we discuss future observational prospects to detect spinning hot haloes around other galaxies. Acceleration and radial streaming motions also comprise significant deviations from HSE, especially net outward accelerations seen in L* and group haloes indicating active feedback. Black hole feedback acts in a preventative manner during the later growth of group haloes, applying significant accelerations via shocks that do not feed tangential motions. We argue that HSE is a poor assumption for the CGM, especially in the inner regions, and rotating baryonic hot haloes are a critical consideration for analytic models of the CGM.

Accepted to MNRAS (15 pages, 6 figures) Revisions include more simulation clarifications, clearer nomenclature, and some equation corrections

References in corpus (27)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• The EAGLE simulations of galaxy formation: calibration of subgrid physics and model variations
• The Circumgalactic Medium
• The effect of photo-ionization on the cooling rates of enriched, astrophysical plasmas
• Chemical enrichment in cosmological, smoothed particle hydrodynamics simulations
• The COS-Halos Survey: Physical Conditions and Baryonic Mass in the Low-Redshift Circumgalactic Medium
• Inviscid SPH
• Four phases of angular-momentum buildup in high-z galaxies: from cosmic-web streams through an extended ring to disc and bulge
• The dark nemesis of galaxy formation: why hot haloes trigger black hole growth and bring star formation to an end
• The COS-Halos Survey: Metallicities in the Low-Redshift Circumgalactic Medium
• Characterizing the Circumgalactic Medium of Nearby Galaxies with HST/COS and HST/STIS Absorption-Line Spectroscopy
• The COS-Dwarfs Survey: The Carbon Reservoir Around sub-L* Galaxies
• Constraining the Milky Way's Hot Gas Halo with OVII and OVII Emission Lines
• The COS-Halos Survey: Origins of the Highly Ionized Circumgalactic Medium of Star-Forming Galaxies
• The abundance, distribution, and physical nature of highly ionized oxygen OVI, OVII, and OVIII in IllustrisTNG
• On the possible environmental effect in distributing heavy elements beyond individual gaseous halos
• Unifying X-ray Scaling Relations from Galaxies to Clusters
• X-ray coronae in simulations of disc galaxy formation
• The baryon fraction of LambdaCDM haloes
• Why stellar feedback promotes disc formation in simulated galaxies
• The origin of the diverse morphologies and kinematics of Milky Way-mass galaxies in the FIRE-2 simulations
• The Properties of the Circumgalactic Medium in Red and Blue Galaxies: Results from the COS-GASS+COS-Halos Surveys
• How to get cool in the heat: comparing analytic models of hot, cold, and cooling gas in haloes and galaxies with EAGLE
• Circumgalactic Oxygen Absorption and Feedback
• The angular momentum of cosmological coronae and the inside-out growth of spiral galaxies
• Adiabatic scaling relations of galaxy clusters

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