Probing the CGM of Low-redshift Dwarf Galaxies Using FIRE Simulations

Abstract

Observations of UV metal absorption lines have provided insight into the structure and composition of the circumgalactic medium (CGM) around galaxies. We compare these observations with the low-redshift ($z\le 0.3$) CGM around dwarf galaxies in high-resolution cosmological zoom-in runs in the FIRE-2 simulation suite. We select simulated galaxies that match the halo mass, stellar mass, and redshift of the observed samples. We produce absorption measurements using Trident for UV transitions of C IV, O VI, Mg II and Si III. The FIRE equivalent width (EW) distributions and covering fractions for the C IV ion are broadly consistent with observations inside $0.5R_{vir}$, but are under-predicted for O VI, Mg II, and Si III. The absorption strengths of the ions in the CGM are moderately correlated with the masses and star formation activity of the galaxies. The correlation strengths increase with the ionization potential of the ions. The structure and composition of the gas from the simulations exhibit three zones around dwarf galaxies characterized by distinct ion column densities: the disky ISM, the inner CGM (the wind-dominated regime), and the outer CGM (the IGM accretion-dominated regime). We find that the outer CGM in the simulations is nearly but not quite supported by thermal pressure, so it is not in hydrostatic equilibrium (HSE), resulting in halo-scale bulk inflow and outflow motions. The net gas inflow rates are comparable to the SFR of the galaxy, but the bulk inflow and outflow rates are greater by an order of magnitude, with velocities comparable to the virial velocity of the halo. These roughly virial velocities ($\sim 100km{s}^{-1}$) produce large EWs in the simulations. This supports a picture for dwarf galaxies in which the dynamics of the CGM at large scales are coupled to the small-scale star formation activity near the centre of their halos.

To appear in MNRAS

References in corpus (70)

• The NumPy array: a structure for efficient numerical computation
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• Cold streams in early massive hot haloes as the main mode of galaxy formation
• Galaxies on FIRE (Feedback In Realistic Environments): Stellar Feedback Explains Cosmologically Inefficient Star Formation
• Properties of galaxies reproduced by a hydrodynamic simulation
• 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
• GIZMO: A New Class of Accurate, Mesh-Free Hydrodynamic Simulation Methods
• FIRE-2 Simulations: Physics versus Numerics in Galaxy Formation
• Ahf: Amiga's Halo Finder
• A New Calculation of the Ionizing Background Spectrum and the Effects of HeII Reionization
• Gusty, gaseous flows of FIRE: galactic winds in cosmological simulations with explicit stellar feedback
• Reconciling dwarf galaxies with LCDM cosmology: Simulating a realistic population of satellites around a Milky Way-mass galaxy
• The COS-Halos Survey: Physical Conditions and Baryonic Mass in the Low-Redshift Circumgalactic Medium
• The Large, Oxygen-Rich Halos of Star-Forming Galaxies Are A Major Reservoir of Galactic Metals
• On the evolution of the HI column density distribution in cosmological simulations
• The 2013 Release of Cloudy
• The evolution substructure I: a new identification method
• The Cosmic Baryon Cycle and Galaxy Mass Assembly in the FIRE Simulations
• Starburst-driven galactic winds: I. Energetics and intrinsic X-ray emission
• The Metal Content of Dwarf Starburst Winds: Results from Chandra Observations of NGC 1569
• Grackle: a Chemistry and Cooling Library for Astrophysics
• Probing the IGM/Galaxy Connection V: On the Origin of Lya and OVI Absorption at z<0.2
• The Current Status of Galaxy Formation
• (Star)bursts of FIRE: observational signatures of bursty star formation in galaxies
• The COS-Dwarfs Survey: The Carbon Reservoir Around sub-L* Galaxies
• Figuring Out Gas & Galaxies in Enzo (FOGGIE). I. Resolving Simulated Circumgalactic Absorption at 2 < z < 2.5
• A Cosmic UV/X-ray Background Model Update
• The Distribution of Metallicity in the IGM at z~2.5: OVI and CIV Absorption in the Spectra of 7 QSOs
• Cosmological simulations of the circumgalactic medium with 1 kpc resolution: enhanced HI column densities
• The Bimodal Metallicity Distribution of the Cool Circumgalactic Medium at z<1
• The Impact of Enhanced Halo Resolution on the Simulated Circumgalactic Medium
• The Origins of the Circumgalactic Medium in the FIRE Simulations
• Gas kinematics, morphology, and angular momentum in the FIRE simulations
• The origin of ultra diffuse galaxies: stellar feedback and quenching
• The Impact of Star Formation Feedback on the Circumgalactic Medium
• The Birth of a Galaxy. II. The Role of Radiation Pressure
• Neutral hydrogen in galaxy halos at the peak of the cosmic star formation history
• Properties of the Circumgalactic Medium in Cosmic Ray-Dominated Galaxy Halos
• The Structure and Dynamical Evolution of the Stellar Disk of a Simulated Milky Way-Mass Galaxy
• On the possible environmental effect in distributing heavy elements beyond individual gaseous halos
• Mining Circumgalactic Baryons in the Low-Redshift Universe
• Constraints on Hydrodynamical Subgrid Models from Quasar Absorption Line Studies of the Simulated Circumgalactic Medium
• What FIREs Up Star Formation: the Emergence of the Kennicutt-Schmidt Law from Feedback
• Zooming in on accretion - II. Cold Circumgalactic Gas Simulated with a super-Lagrangian Refinement Scheme
• Metal-enriched, sub-kiloparsec gas clumps in the circumgalactic medium of a faint z = 2.5 galaxy
• IGM Emission Observations with the Cosmic Web Imager: I. The Circum-QSO Medium of QSO 1549+19, and Evidence for a Filamentary Gas Inflow
• Simulating an Isolated Dwarf Galaxy with Multi-Channel Feedback and Chemical Yields from Individual Stars
• Hydrogen and Metal Line Absorption Around Low-Redshift Galaxies in Cosmological Hydrodynamic Simulations
• The Column Density, Kinematics, and Thermal State of Metal-Bearing Gas within the Virial Radius of z~2 Star-Forming Galaxies in the Keck Baryonic Structure Survey
• A Stellar Feedback Origin for Neutral Hydrogen in High-Redshift Quasar-Mass Halos
• Cooling flow solutions for the circumgalactic medium
• A Chandra X-ray survey of nearby dwarf starburst galaxies: II. Starburst properties and outflows
• Trident: a universal tool for generating synthetic absorption spectra from astrophysical simulations
• Low-Redshift Lyman Limit Systems as Diagnostics of Cosmological Inflows and Outflows
• The formation of massive, quiescent galaxies at cosmic noon
• The extent of chemically enriched gas around star-forming dwarf galaxies
• The Fates of the Circumgalactic Medium in the FIRE Simulations
• Implications of the large OVI columns around low-redshift $L_{\ast }$ galaxies
• Deviations from hydrostatic equilibrium in the circumgalactic medium: spinning hot haloes and accelerating flows
• The maximum accretion rate of hot gas in dark matter halos
• Massive Warm/Hot Galaxy Coronae: II. Isentropic Model
• Chandra Observation of NGC4449. Analysis of the X-ray Emission from a Dwarf Starburst Galaxy
• Swirls of FIRE: Spatially Resolved Gas Velocity Dispersions and Star Formation Rates in FIRE-2 Disk Environments
• Introducing CGOLS: The Cholla Galactic OutfLow Simulation Suite
• Circumgalactic Oxygen Absorption and Feedback
• Properties of the Simulated Circumgalactic Medium
• Chandra & XMM-Newton Observations of NGC5253. Analysis of the X-ray Emission from a Dwarf Starburst Galaxy
• Chandra and XMM-Newton Observations of NGC 4214: The Hot Interstellar Medium and the Luminosity Function of Dwarf Starbursts
• Emission from the circumgalactic medium: from cosmological zoom-in simulations to multiwavelength observables

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• FIRE-3: Updated Stellar Evolution Models, Yields, & Microphysics and Fitting Functions for Applications in Galaxy Simulations
• A Comparison of Circumgalactic MgII Absorption between the TNG50 Simulation and the MEGAFLOW Survey
• MusE GAs Flow and Wind (MEGAFLOW) VI. A study of CIV and MgII absorbing gas surrounding [OII] emitting galaxies
• OVI Traces Photoionized Streams With Collisionally Ionized Boundaries in Cosmological Simulations of $z\sim 1$ Massive Galaxies
• The QuaStar Survey: Detecting Hidden Low-Velocity Gas in the Milky Way's Circumgalactic Medium
• It's a Breeze: The Circumgalactic Medium of a Dwarf Galaxy is Easy to Strip
• Evolution of CIV Absorbers. II. Where does CIV live?