Interpreting Observations of Absorption Lines in the Circumgalactic Medium with a Turbulent Medium

Abstract

Single-phase photoionization equilibrium (PIE) models are often used to infer the underlying physical properties of galaxy halos probed in absorption with ions at different ionization potentials. To incorporate the effects of turbulence, we use the MAIHEM code to model an isotropic turbulent medium exposed to a redshift zero metagalactic UV background, while tracking the ionizations, recombinations, and species-by-species radiative cooling for a wide range of ions. By comparing observations and simulations over a wide range of turbulent velocities, densities, and metallicity with a Markov chain Monte Carlo technique, we find that MAIHEM models provide an equally good fit to the observed low-ionization species compared to PIE models, while reproducing at the same time high-ionization species such as \ion{Si}{4} and \ion{O}{6}. By including multiple phases, MAIHEM models favor a higher metallicity ($Z/Z_{\odot }\approx 40\%$) for the circumgalactic medium compared to PIE models. Furthermore, all of the solutions require some amount of turbulence (${\sigma }_{3D}⩾26\mathrm{km}{\mathrm{s}}^{-1}$). Correlations between turbulence, metallicity, column density, and impact parameter are discussed alongside mechanisms that drive turbulence within the halo.

arXiv comment19 pages, 13 figures, accepted in ApJ

References in corpus (47)

• emcee: The MCMC Hammer
• A Multi-Code Analysis Toolkit for Astrophysical Simulation Data
• Radiative transfer in a clumpy universe: IV. New synthesis models of the cosmic UV/X-ray background
• The Circumgalactic Medium
• Gas-regulation of galaxies: the evolution of the cosmic sSFR, the metallicity-mass-SFR relation and the stellar content of haloes
• The COS-Halos Survey: Physical Conditions and Baryonic Mass in the Low-Redshift Circumgalactic Medium
• Highly-Ionized High-Velocity Gas in the Vicinity of the Galaxy
• A cosmic web filament revealed in Lyman-alpha emission around a luminous high-redshift quasar
• The COS-Halos Survey: Rationale, Design, and A Census of Circumgalactic Neutral Hydrogen
• The COS-Halos Survey: An Empirical Description of the Metal-Line Absorption in the Low-Redshift Circumgalactic Medium
• Probing the IGM/Galaxy Connection V: On the Origin of Lya and OVI Absorption at z<0.2
• An Empirical Characterization of Extended Cool Gas Around Galaxies Using MgII Absorption Features
• A huge reservoir of ionized gas around the Milky Way: Accounting for the Missing Mass?
• The COS-Halos Survey: Metallicities in the Low-Redshift Circumgalactic Medium
• A High-Resolution Survey of Low-Redshift QSO Absorption Lines: Statistics and Physical Conditions of O VI Absorbers
• Constraining the Milky Way's Hot Gas Halo with OVII and OVII Emission Lines
• The Bimodal Metallicity Distribution of the Cool Circumgalactic Medium at z<1
• The COS-Halos Survey: Origins of the Highly Ionized Circumgalactic Medium of Star-Forming Galaxies
• Metal flows of the circumgalactic medium, and the metal budget in galactic halos
• A Solution Accurate, Efficient and Stable Unsplit Staggered Mesh Scheme for Three Dimensional Magnetohydrodynamics
• The Hidden Mass and Large Spatial Extent of a Poststarburst Galaxy Outflow
• Not Dead Yet: Cool Circumgalactic Gas in the Halos of Early Type Galaxies
• Metal-enriched, sub-kiloparsec gas clumps in the circumgalactic medium of a faint z = 2.5 galaxy
• The Properties of Low Redshift Intergalactic O VI Absorbers Determined from High S/N Observations of 14 QSOs with the Cosmic Origins Spectrograph
• Galactic and Circumgalactic OVI and its Impact on the Cosmological Metal and Baryon Budgets at 2<z<3.5
• Extended Hot Halos Around Isolated Galaxies Observed in the ROSAT All-Sky Survey
• A Universal Density Structure for Circum-Galactic Gas
• The physical properties of z>2 Lyman limit systems: new constraints for feedback and accretion models
• A Role for Turbulence in Circumgalactic Precipitation
• Gas Condensation in the Galactic Halo
• Implications of the large OVI columns around low-redshift $L_{\ast }$ galaxies
• The origin of the high-velocity cloud complex C
• The Cosmic Evolution of the Metallicity Distribution of Ionized Gas Traced by Lyman Limit Systems
• Precipitation-Regulated Star Formation in Galaxies
• Characterizing Transition Temperature Gas in the Galactic Corona
• Mixing in Supersonic Turbulence
• Ongoing Galactic Accretion: Simulations and Observations of Condensed Gas in Hot Halos
• The Keck+Magellan Survey for Lyman Limit Absorption III: Sample Definition and Column Density Measurements
• Fast Winds Drive Slow Shells: A Model for the Circumgalactic Medium as Galactic Wind-Driven Bubbles
• Metal-Absorption Column Densities in Fast Radiative Shocks
• The Relationship Between Galaxy ISM and Circumgalactic Gas Metallicities
• Atomic Chemistry In Turbulent Astrophysical Media I: Effect of Atomic Cooling
• The Effect of Turbulence on Nebular Emission Line Ratios
• Observing the circumgalactic medium of simulated galaxies through synthetic absorption spectra
• Atomic Chemistry in Turbulent Astrophysical Media II: Effect of the Redshift Zero Metagalactic Background
• Modeling Photoionized Turbulent Material in the Circumgalactic Medium
• Column Density Profiles of Cold Clouds Driven by Galactic Outflows

Cited by in corpus (6)

• MUSE Analysis of Gas around Galaxies (MAGG) -- III: The gas and galaxy environment of z = 3-4.5 quasars
• The COS Absorption Survey of Baryon Harbors: Unveiling the Physical Conditions of Circumgalactic Gas through Multiphase Bayesian Ionization Modeling
• Mixing matters
• Sub-damped Lyman alpha systems in the XQ-100 survey II -- Chemical evolution at 2.4<z<4.3
• Modeling Photoionized Turbulent Material in the Circumgalactic Medium II: Effect of Turbulence within a Stratified Medium
• Modeling Photoionized Turbulent Material in the Circumgalactic Medium III: Effects of Co-rotation and Magnetic Fields