The COS/UVES Absorption Survey of the Magellanic Stream. III: Ionization, Total Mass, and Inflow Rate onto the Milky Way

Abstract

Dynamic interactions between the two Magellanic Clouds have flung large quantities of gas into the halo of the Milky Way, creating the Magellanic Stream, the Magellanic Bridge, and the Leading Arm (collectively referred to as the Magellanic System). In this third paper of a series studying the Magellanic gas in absorption, we analyze the gas ionization level using a sample of 69 Hubble Space Telescope/Cosmic Origins Spectrograph sightlines that pass through or within 30 degrees of the 21 cm-emitting regions. We find that 81% (56/69) of the sightlines show UV absorption at Magellanic velocities, indicating that the total cross section of the Magellanic System is ~11 000 square degrees, or around a quarter of the entire sky. Using observations of the Si III/Si II ratio together with Cloudy photoionization modeling, we calculate that the total mass (atomic plus ionized) of the Magellanic System is ~2.0 billion solar masses, with the ionized gas contributing over twice as much mass as the atomic gas. This is larger than the current-day interstellar H I mass of both Magellanic Clouds combined, indicating that they have lost most of their initial gas mass. If the gas in the Magellanic System survives to reach the Galactic disk over its inflow time of ~0.5-1.5 Gyr, it will represent an average inflow rate of ~3.7-6.7 solar masses per year, potentially raising the Galactic star formation rate. However, multiple signs of an evaporative interaction with the hot Galactic corona indicate that the Stream may not survive its journey to the disk fully intact, and will instead add material to (and cool) the corona.

arXiv commentAccepted for publication in ApJ, 32 pages, 7 figures, 3 tables, Figure 1 shown at low resolution to reduce file size

References in corpus (120)

• The chemical composition of the Sun
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• How Do Galaxies Get Their Gas?
• Radiative transfer in a clumpy universe: IV. New synthesis models of the cosmic UV/X-ray background
• Galaxies in a simulated $\Lambda$CDM Universe I: cold mode and hot cores
• Abundance Gradients and the Formation of the Milky Way
• Gaseous Galaxy Halos
• The Cosmic Origins Spectrograph
• Highly-Ionized High-Velocity Gas in the Vicinity of the Galaxy
• Third-Epoch Magellanic Cloud Proper Motions I: HST/WFC3 data and Orbit Implications
• Multi-Phase Galaxy Formation: High Velocity Clouds and the Missing Baryon Problem
• HI in Local Group Dwarf Galaxies and Stripping by the Galactic Halo
• The Star Formation History of the Small Magellanic Cloud
• The Wisconsin H-Alpha Mapper Northern Sky Survey
• GASS: The Parkes Galactic All-Sky Survey. I. Survey Description, Goals, and Initial Data Release
• Time-Dependent Ionization in Radiatively Cooling Gas
• The Role of Dwarf Galaxy Interactions in Shaping the Magellanic System and Implications for Magellanic Irregulars
• Toward a Unification of Star Formation Rate Determinations in the Milky Way and Other Galaxies
• Distances and Metallicities of High- and Intermediate-Velocity Clouds
• N-body Simulations of the Small Magellanic Cloud and the Magellanic Stream
• The Search for the Missing Baryons at Low Redshift
• Absorption line systems in simulated galaxies fed by cold streams
• The present-day star formation rate of the Milky-Way determined from Spitzer detected young stellar objects
• The Magellanic Stream, High-Velocity Clouds and the Sculptor Group
• A huge reservoir of ionized gas around the Milky Way: Accounting for the Missing Mass?
• The Origin of the Magellanic Stream and Its Leading Arm
• The disruption of nearby galaxies by the Milky Way
• Simulations of the Magellanic Stream in a First Infall Scenario
• A New Look at the Large-Scale HI Structure of the LMC
• The Parkes HI Survey of the Magellanic System
• Chemical Evolution of the Magellanic Clouds: analytical models
• The Structure of the Milky Way's Hot Gas Halo
• The Bimodal Metallicity Distribution of the Cool Circumgalactic Medium at z<1
• The circumgalactic medium of massive galaxies at z~3: a test for stellar feedback, galactic outflows, and cold streams
• HI kinematics and dynamics of Messier 31
• The Origin of the Magellanic Stream
• The Tidal Origin of the Magellanic Stream and the Possibility of a Stellar Counterpart
• GASS: The Parkes Galactic All-Sky Survey. II. Stray-Radiation Correction and Second Data Release
• On the Continuing Formation of the Andromeda Galaxy: Detection of HI Clouds in the M31 Halo
• Moving mesh cosmology: numerical techniques and global statistics
• The Westerbork Hydrogen Accretion in Local Galaxies (HALOGAS) Survey I. Survey Description and Pilot Observations
• The Escape of Ionizing Photons from the Galaxy
• H_alpha Emission from High-Velocity Clouds and their Distances
• Multi-phase High-Velocity Clouds toward HE 0226-4110 and PG 0953+414
• The 200 Degree-Long Magellanic Stream System
• The gravitational and hydrodynamical interaction between the LMC and the Galaxy
• Properties of gas in and around galaxy haloes
• The Direct Detection of Cool, Metal-Enriched Gas Accretion onto Galaxies at z ~ 0.5
• The Age of the Solar Neighbourhood
• A Reservoir of Ionized Gas in the Galactic Halo to Sustain Star Formation in the Milky Way
• Complex C: A Low-Metallicity High-Velocity Cloud Plunging into the Milky Way
• Non-Equilibirum ionisation and cooling of metal-enriched gas in the presence of a photo-ionisation background
• The Fate of High-Velocity Clouds: Warm or Cold Cosmic Rain?
• N-body simulations of the Magellanic Stream
• An Accurate Distance to High-Velocity Cloud Complex C
• Atomic Hydrogen Gas in Dark-Matter Minihalos and the Compact High Velocity Clouds
• Highly Ionized Gas Surrounding High Velocity Cloud Complex C
• Small-Scale Structure in the SDSS and LCDM: Isolated L* Galaxies with Bright Satellites
• Detection of H-alpha emission from the Magellanic Stream: evidence for an extended gaseous Galactic halo
• The Source of Ionization along the Magellanic Stream
• A Large Reservoir of Ionized Gas in the Galactic Halo: Ionized Silicon in High-Velocity and Intermediate-Velocity Clouds
• On the Hot Gas Content of the Milky Way Halo
• The Metallicity and Dust Content of HVC 287.5+22.5+240: Evidence for a Magellanic Clouds Origin
• Evidence for Cold Accretion: Primitive Gas Flowing onto a Galaxy at z~0.274
• High-velocity clouds as streams of ionized and neutral gas in the halo of the Milky Way
• A Survey of O VI, C III, and H I in Highly Ionized High-Velocity Clouds
• Metal Abundances in the Magellanic Stream
• Exploring the Origin and Fate of the Magellanic Stream with Ultraviolet and Optical Absorption
• The Gas Consumption History to z ~ 4
• Highly Ionized High Velocity Clouds: Intergalactic Gas in the Local Group or Distant Gas in the Galactic Halo?
• FUSE Observations of Atomic Abundances and Molecular Hydrogen in the Leading Arm of the Magellanic Stream
• Gas Condensation in the Galactic Halo
• Discovery of a Population of HI Clouds in the Galactic Halo
• Fossil imprint of a powerful flare at the Galactic Centre along the Magellanic Stream
• Molecular Hydrogen in High-Velocity Clouds
• The COS/UVES Absorption Survey of the Magellanic Stream: II. Evidence for a complex enrichment history of the Stream from the Fairall 9 sightline
• The COS/UVES Absorption Survey of the Magellanic Stream: I. One-Tenth Solar Abundances along the Body of the Stream
• Highly Ionized High-Velocity Clouds: Hot Intergalactic Medium or Galactic Halo?
• EVLA Observations of Galactic Supernova Remnants: Wide-field Continuum and Spectral-index Imaging
• Observing the End of Cold Flow Accretion using Halo Absorption Systems
• Highly Ionized High-Velocity Clouds toward PKS 2155-304 and Markarian 509
• Discrete clouds of neutral gas between the galaxies M31 and M33
• The small-scale structure of the Magellanic Stream
• Gas Accretion is Dominated by Warm Ionized Gas in Milky Way-Mass Galaxies at z ~ 0
• A Groundbased Imaging Study of Galaxies Causing DLA, subDLA, and LLS Absorption in Quasar Spectra
• Ongoing Galactic Accretion: Simulations and Observations of Condensed Gas in Hot Halos
• The High Velocity Gas toward Messier 5: Tracing Feedback Flows in the Inner Galaxy
• A Near-Solar Metallicity, Nitrogen-Deficient Lyman Limit Absorber Associated with two S0 Galaxies
• The many streams of the Magellanic Stream
• Hubble Space Telescope Survey of Interstellar High-Velocity Si III
• The Magellanic Stream and the density of coronal gas in the Galactic halo
• Highly ionised plasma in the Large Magellanic Cloud: Evidence for outflows and a possible galactic wind
• The neutral gas extent of galaxies as derived from weak intervening CaII absorbers
• Highly Ionized Gas in the Galactic Halo and the High Velocity Clouds Toward PG 1116+215
• Ionized absorbers as evidence for supernova-driven cooling of the lower Galactic corona
• An Interaction of a Magellanic Leading Arm High Velocity Cloud with the Milky Way Disk
• Metallicity and Physical Conditions in the Magellanic Bridge
• A population of weak metal-line absorbers surrounding the Milky Way
• The Origin and Distribution of Cold Gas in the Halo of a Milky Way-Mass Galaxy
• Cold gas accretion by high-velocity clouds and their connection to QSO absorption-line systems
• Hubble-COS Observations of Galactic High-Velocity Clouds: Four AGN Sight Lines through Complex C
• Properties and Origin of the High-Velocity Gas Toward the Large Magellanic Cloud
• Warm Ionized Gas Revealed in the Magellanic Bridge Tidal Remnant: Constraining the Baryon Content and the Escaping Ionizing Photons around Dwarf Galaxies
• On the origin of the warm-hot absorbers in the Milky Way's halo
• The High-Ion Content and Kinematics of Low-Redshift Lyman Limit Systems
• A Limit on the Metallicity of Compact High Velocity Clouds
• Magnetized Gas in the Smith High Velocity Cloud
• Origin(s) of the Highly Ionized High-Velocity Clouds Based on Their Distances
• Green Bank Telescope observations of low column density HI around NGC 2997 and NGC 6946
• Compact HI clouds at high forbidden velocities in the inner Galaxy
• The scattered debris of the Magellanic Stream
• The Milky Way halo as a QSO absorption-line system. New results from an HST/STIS absorption-line catalogue of Galactic high-velocity clouds
• Measurement of Noisy Absorption Lines using the Apparent Optical Depth Technique
• The Evolution of Gas Clouds Falling in the Magnetized Galactic Halo: High Velocity Clouds (HVCs) Originated in the Galactic Fountain
• Infrared Laboratory Oscillator Strengths of Fe I in the H-Band
• The 21cm "Outer Arm" and the Outer-Galaxy High-Velocity Clouds: Connected by Kinematics, Metallicity, and Distance
• Geometrodynamical Distances to the Galaxy's Hydrogen Streams
• The Magellanic Bridge as a DLA System: Physical Properties of Cold Gas toward PKS0312-770
• A warm mode of gas accretion on forming galaxies
• Probing the Structure and Kinematics of the transition Layer between the Magellanic Stream and the Halo in HI

Cited by in corpus (130)

• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• The Circumgalactic Medium
• Probing Galactic Halos with Fast Radio Bursts
• Star formation sustained by gas accretion
• The Magellanic Stream: Circumnavigating the Galaxy
• And yet it moves: The dangers of artificially fixing the Milky Way center of mass in the presence of a massive Large Magellanic Cloud
• The Mass and Momentum Outflow Rates of Photoionized Galactic Outflows
• The survival of gas clouds in the Circumgalactic Medium of Milky Way-like galaxies
• A fast radio burst in the direction of the Carina dwarf spheroidal galaxy
• Scaling Relations Between Warm Galactic Outflows and Their Host Galaxies
• Gaia early DR3 systemic motions of Local Group dwarf galaxies and orbital properties with a massive Large Magellanic Cloud
• Ram Pressure Stripping of the Large Magellanic Cloud's Disk as a Probe of the Milky Way's Circumgalactic Medium
• The Gas Content and Stripping of Local Group Dwarf Galaxies
• Metal-enriched galactic outflows shape the mass-metallicity relationship
• Galactic outflow rates in the EAGLE simulations
• TiNy Titans: The Role of Dwarf-Dwarf Interactions in the Evolution of Low Mass Galaxies
• Quasars Probing Galaxies: I. Signatures of Gas Accretion at Redshift Approximately 0.2
• Evidence for a Massive, Extended Circumgalactic Medium Around the Andromeda Galaxy
• An HST/COS legacy survey of high-velocity ultraviolet absorption in the Milky Way's circumgalactic medium and the Local Group
• Probing the Fermi Bubbles in Ultraviolet Absorption: A Spectroscopic Signature of the Milky Way's Biconical Nuclear Outflow
• Gas Accretion via Condensation and Fountains
• The Magellanic Stream System: I. Ram-pressure tails and the relics of the collision between the Magellanic Clouds
• Gaia EDR3 proper motions of Milky Way dwarfs I: 3D Motions and Orbits
• Nuclear Outflow of the Milky Way: Studying the Kinematics and Spatial Extent of the Northern Fermi Bubble
• Local Volume TiNy Titans: Gaseous Dwarf-Dwarf Interactions in the Local Universe
• Shining A Light On Galactic Outflows: Photo-Ionized Outflows
• Do galaxies that leak ionizing photons have extreme outflows?
• Project AMIGA: The Circumgalactic Medium of Andromeda
• The effect of the LMC on the Milky Way system
• Revealing the tidal scars of the Small Magellanic Cloud
• The large-scale ionization cones in the Galaxy
• On the Metallicity and Origin of the Smith High-Velocity Cloud
• The Magellanic Stream at 20 kpc: A New Orbital History for the Magellanic Clouds
• The Magellanic Corona and the formation of the Magellanic Stream
• The Frequency of Dwarf Galaxy Multiples at Low Redshift in SDSS vs. Cosmological Expectations
• Direct Insights into Observational Absorption Line Analysis Methods of the Circumgalactic Medium Using Cosmological Simulations
• Toward a Complete Understanding of the Magellanic Stream Formation
• Models of Tidally Induced Gas Filaments in the Magellanic Stream
• On the origin of excess cool gas in quasar host halos
• The Mass Inflow and Outflow Rates of the Milky Way
• Galactic inflow and wind recycling rates in the EAGLE simulations
• How Gas Accretion Feeds Galactic Disks
• The Structure of the Circumgalactic Medium of Galaxies: Cool Accretion Inflow Around NGC 1097
• Magnetic fields in the Galactic halo restrict fountain-driven recycling and accretion
• The Circumgalactic Medium of the Milky Way is Half Hidden
• HST/COS Observations of Ionized Gas Accretion at the Disk-halo Interface of M33
• The Dispersion of Fast Radio Bursts from a Structured Intergalactic Medium at Redshifts z < 1.5
• Intermediate- and high-velocity clouds in the Milky Way I: covering factors and vertical heights
• A Genetic Approach to the History of the Magellanic Clouds
• Observations of a Magellanic Corona
• The Magellanic Stream: break up and accretion onto the hot Galactic corona
• The Nature of Ionized Gas in the Milky Way Galactic Fountain
• Orbital evidences for dark-matter-free Milky Way dwarf spheroidal galaxies
• Revealing the Milky Way's Hidden Circumgalactic Medium with the Cosmic Origins Spectrograph Quasar Database for Galactic Absorption Lines
• WALLABY Early Science - II. The NGC 7232 galaxy group
• Cosmic Ray Driven Outflows from the Large Magellanic Cloud: Contributions to the LMC Filament
• The Magellanic System: the puzzle of the leading gas stream
• Gas Accretion onto the Milky Way
• Discovery of the Magellanic Stellar Stream Out to 100 Kiloparsecs
• Chemical Abundances in the Leading Arm of the Magellanic Stream
• Figuring Out Gas & Galaxies in Enzo (FOGGIE). III. The Mocky Way: Investigating Biases in Observing the Milky Way's Circumgalactic Medium
• Revealing the physical properties of gas accreting to haloes in the EAGLE simulations
• On the neutral gas content of nine new Milky Way satellite galaxy candidates
• Sensitive 21cm Observations of Neutral Hydrogen in the Local Group near M31
• Probing the Southern Fermi Bubble in Ultraviolet Absorption using Distant AGNs
• Local ultra faint dwarves as a product of Galactic processing during a Magellanic group infall
• Shrinking Galaxy Disks with Fountain-Driven Accretion from the Halo
• Collisions between Dark Matter Confined High Velocity Clouds and Magnetized Galactic Disks: The Smith Cloud
• Revealing the Ionization Properties of the Magellanic Stream using Optical Emission
• Galactic Gas Flows from Halo to Disk: Tomography and Kinematics at the Milky Way's Disk-Halo Interface
• Down-the-barrel and transverse observations of the Large Magellanic Cloud: evidence for a symmetrical galactic wind on the near and far sides of the galaxy
• On the nature of a shell of young stars in the outskirts of the Small Magellanic Cloud
• Project AMIGA: A Minimal Covering Factor for Optically Thick Circumgalactic Gas Around the Andromeda Galaxy
• Impact of the Galactic Disk and Large Magellanic Cloud on the Trajectories of Hypervelocity Stars Ejected from the Galactic Center
• Kinematics of the Magellanic Stream and Implications for its Ionization
• Si iv Column Densities Predicted from Non-Equilibrium Ionization Simulations of Turbulent Mixing Layers and High-Velocity Clouds
• An Introduction to Gas Accretion onto Galaxies
• GASKAP Pilot Survey Science II: ASKAP Zoom Observations of Galactic 21-cm Absorption
• The Fate of Supernova-Heated Gas in Star-Forming Regions of the LMC: Lessons for Galaxy Formation?
• New constraints on the nature and origin of the Leading Arm of the Magellanic Stream
• Tracing the Milky Way's Vestigial Nuclear Jet
• The warm Gaseous Disk and the Anisotropic Circumgalactic Medium of the Milky Way
• The Warm Gas in the MW: A Kinematical Model
• Cold and Hot gas distribution around the Milky-Way-M31 system in the HESTIA simulations
• The QuaStar Survey: Detecting Hidden Low-Velocity Gas in the Milky Way's Circumgalactic Medium
• Characterizing the Circumgalactic Medium of the Lowest-Mass Galaxies: A Case Study of IC 1613
• High-velocity gas towards the LMC resides in the Milky Way halo
• It's a Breeze: The Circumgalactic Medium of a Dwarf Galaxy is Easy to Strip
• Radiative Turbulent Mixing Layers and the Survival of Magellanic Debris
• Discovery of High-Velocity H$\alpha$ Emission in the Direction of the Fermi Bubble
• Properties of the Magellanic Corona
• The Diffuse Ionized Gas Halo of the Small Magellanic Cloud
• Tentative Detection of the Circumgalactic Medium of the Isolated Low-Mass Dwarf Galaxy WLM
• The CGM-GRB Study. I. Uncovering The CircumGalactic Medium around GRB hosts at redshifts 2-6
• Spatially Resolved Gas Flows Around the Milky Way
• On the distribution of the Cold Neutral Medium in galaxy discs
• Caught in the Act: A Metal-Rich High-Velocity Cloud in the Inner Galaxy
• Diverse metallicities of Fermi bubble clouds indicate dual origins in the disk and halo
• Circumgalactic gas at its extreme: tidal gas streams around the Whale galaxy NGC 4631 explored with HST/COS
• Physical Conditions of Five O VI Absorption Systems Towards PG $1522+101$
• H$\alpha$ Distances to the Leading Arm of the Magellanic Stream
• Lessons from the Magellanic System and its modeling
• Large and small-scale structure of the Intermediate and High Velocity Clouds towards the LMC and SMC
• First Detection of HCO${}^{+}$ Absorption in the Magellanic System
• A Compact High Velocity Cloud near the Magellanic Stream: Metallicity and Small-Scale Structure
• Charge exchange emission and cold clumps in multi-phase galactic outflows
• On the Origin of High-velocity Clouds in the Galaxy
• A population of high-velocity absorption-line systems residing in the Local Group
• Investigating the Baryon Cycle in Interacting Dwarfs with the Very Large Array and Pan-STARRS
• The Diffuse Ionized Gas of the Large Magellanic Cloud
• Following the tidal trail: a history of modeling the Magellanic Stream
• Discovery of the Goat Horn complex: a $\sim 1000$ deg${}^2$ diffuse X-ray source connected to radio loop XII
• The Origins of Young Stars in the Direction of the Leading Arm of the Magellanic Stream: Abundances, Kinematics, and Orbits
• The Evolution of Magellanic-like Galaxy Pairs and The Production of Magellanic Stream Analogues in Simulations with Tides, Ram Pressure, and Stellar Feedback
• The Warm Gas in the MW: the Kinematical Model of C IV and its Connection with Si IV
• The Long Tails of the Pegasus-Pisces Arch Intermediate Velocity Cloud
• Kinematics of the Local Group gas and galaxies in the Hestia simulations
• Neutral Gas Accretion onto Nearby Galaxies
• Stellar initial mass function variation in massive early-type galaxies: the potential role of the deuterium abundance
• A path towards constraining the evolution of the interstellar medium and outflows in the Milky Way using APOGEE
• The influence of atomic alignment on absorption and emission spectroscopy
• Hydrodynamics of Clustered Clouds: Drafting, Survival, Condensation, and Ablation
• AGN in the ULIRG HE 0435-5304
• The Discovery and Origin of A Very-High Velocity Cloud Toward M33
• Cosmic Rays and Non-thermal Emission Induced by Accretion of Cool Gas onto the Galactic Disk
• The distribution and kinematics of interstellar O~{\small VI} in the Milky Way}
• The WSRT HALOGAS Survey
• Simulating High-Velocity Clouds in the Observational Plane: An Initial Study with the Smith Cloud
• Quasars behind the disk of M31 galaxy
• Modeling the Accretion of High-Velocity Clouds from a Rotating Halo