Properties of O VI Absorption in the Local Interstellar Medium

Abstract

We report on the properties of LISM O VI absorption observed with 20 km/s resolution FUSE observations of 39 white dwarfs (WDs) ranging in distance from 37 to 230 pc with a median distance of 109 pc. LISM O VI is detected with >2sigma significance along 24 of 39 lines of sight. The column densities range from log N(O VI) = 12.38 to 13.60 with a median value of 13.10. The line of sight volume density, n(O VI) = N(O VI)/d exhibits a large dispersion ranging from (0.68 to 13.0)x10(-8) cm(-3) with an average value 3.6x10(-8) cm(-3) twice larger than found for more distant sight lines in the Galactic disk. The narrowest profiles are consistent with thermal Doppler broadening of O VI near its temperature of peak abundance, 2.8x10(5) K. Comparison of the average velocities of O VI and C II absorption reveals 10 cases where the O VI absorption is closely aligned with the C II absorption as expected if the O VI is formed in a condensing interface between the cool and warm absorption and a hot exterior gas. The comparison also reveals 13 cases where O VI absorption is displaced to positive velocity by 7 to 29 km/s from the average velocity of C II. The positive velocity O VI appears to be tracing the evaporative flow of O VI from a young interface between warm gas and a hot exterior medium. However, it is possible the positive velocity O VI is instead tracing cooling hot Local Bubble (LB) gas. The properties of the O VI absorption in the LISM are broadly consistent with the expectations of the theory of conductive interfaces caught in the old condensing phase and possibly in the young evaporative phase of their evolution.

arXiv comment64 pages and 12 figures. Accepted by the Astrophysical Journal Supplement, January 2006, v162

References in corpus (35)

• Overview of the Far Ultraviolet Spectroscopic Explorer Mission
• Highly-Ionized High-Velocity Gas in the Vicinity of the Galaxy
• On-Orbit Performance of the Far Ultraviolet Spectroscopic Explorer (FUSE) Satellite
• Intervening O VI Quasar Absorption Systems at Low Redshift: A Significant Baryon Reservoir
• Chandra Discovery of a Tree in the X-ray Forest towards PKS 2155-304: the Local Filament?
• Distribution and Kinematics of O VI in the Galactic Halo
• Multi-phase High-Velocity Clouds toward HE 0226-4110 and PG 0953+414
• The origin of the Local Bubble
• An OVI Baryon Census of the Low-z Warm-Hot Intergalactic Medium
• Highly Ionized Gas Surrounding High Velocity Cloud Complex C
• On the Physical Origin of OVI Absorption-Line Systems
• Physical Properties and Baryonic Content of Low-Redshift Intergalactic Ly-alpha and O VI Absorption Systems: The PG1116+215 Sight Line
• FUSE Survey of the Local Interstellar Medium within 200 Parsec
• The Structure of the Local Interstellar Medium. II. Observations of D I, C II, N I, O I, Al II, and Si II toward Stars within 100 parsecs
• X-ray Absorption Line Spectroscopy of the Galactic Hot Interstellar Medium
• FUSE and STIS Observations of the Warm-Hot Intergalactic Medium towards PG1259+593
• Chandra Detection of Local OVII He-alpha Absorption Along the Sight Line Toward 3C 273
• A Survey of OVI Absorption in the Local Interstellar Medium
• FUSE Observations of the Galactic and Intergalactic Medium Towards H1821+643
• O VII and O VIII absorption by hot gas in the vicinity of the Galaxy
• The Global Content, Distribution, and Kinematics of Interstellar O VI in the Large Magellanic Cloud
• Highly-Ionized Gas in the Galactic Halo: A FUSE Survey of O VI Absorption toward 22 Halo Stars
• OVI, NV, and CIV in the Galactic Halo: I. Velocity-Dependent Ionization Models
• Abundances of Deuterium, Nitrogen, and Oxygen toward HZ 43A: Results from the FUSE Mission
• Observations of O VI Emission from the Diffuse Interstellar Medium
• Deep-Ocean Crusts as Telescopes: Using Live Radioisotopes to Probe Supernova Nucleosynthesis
• FUSE Observations of the Magellanic Bridge Gas toward Two Early-Type Stars: Molecules, Physical Conditions, and Relative Abundance
• Deuterium Toward WD1634-573: Results from the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission
• Circumstellar features in hot DA white dwarfs
• Detection of highly ionized O and Ne absorption lines in the X-ray spectrum of 4U1820-303 in the globular cluster, NGC 6624
• OVI Emission in the Halos of Edge-on Spiral Galaxies
• FUSE Observations of Interstellar and Intergalactic Absorption Toward the X-ray Bright BL Lac Object Mrk 421
• O/H in the Local Bubble
• ORFEUS-II Far-Ultraviolet Observations of 3C273: 1. Interstellar and Intergalactic Absorption Lines
• FUSE Observations of the Cygnus Loop: OVI Emission from a Nonradiative Shock

Cited by in corpus (54)

• A Unified Representation of Gas-Phase Element Depletions in the Interstellar Medium
• A High-Resolution Survey of Low-Redshift QSO Absorption Lines: Statistics and Physical Conditions of O VI Absorbers
• New 3-D gas density maps of NaI and CaII interstellar absorption within 300pc
• The search for the origin of the Local Bubble redivivus
• The Far Ultraviolet Spectroscopic Explorer Survey of OVI Absorption in the Disk of the Milky Way
• 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
• The History and Future of the Local and Loop I Bubbles
• Evolution of supernovae-driven superbubbles with conduction and cooling
• The Extension of the Transition Temperature Plasma into the Lower Galactic Halo
• The Trouble with the Local Bubble
• QSO Absorption Systems Detected in Ne VIII: High-Metallicity Clouds with a Large Effective Cross Section
• Characterizing Transition Temperature Gas in the Galactic Corona
• The High Velocity Gas toward Messier 5: Tracing Feedback Flows in the Inner Galaxy
• Highly ionised plasma in the Large Magellanic Cloud: Evidence for outflows and a possible galactic wind
• O VI Absorbers Tracing Hot Gas Associated with a Pair of Galaxies at z = 0.167
• A Multiphase Absorber Containing O VI and Broad H I Directly Tracing 10^6 K Plasma at Low-Redshift Toward HE 0153-4520
• Spatial distribution of interstellar dust in the Sun vicinity, comparison with neutral sodium-bearing gas
• Metal-Ion Absorption in Conductively Evaporating Clouds
• High resolution X-ray spectroscopy of the multiphase interstellar medium toward Cyg X-2
• Numerical studies on the link between radioisotopic signatures on Earth and the formation of the Local Bubble. I. 60Fe transport to the solar system by turbulent mixing of ejecta from nearby supernovae into a locally homogeneous ISM
• Fundamental Properties of the Highly Ionized Plasmas in the Milky Way
• Cos observations of metal line and broad lyman alpha absorption in the multi-phase o vi and ne viii system toward he 02226-4110
• An Extended FUSE Survey of Diffuse O VI Emission in the Interstellar Medium
• O vi in the local interstellar medium
• Detection of Ne VIII in an Intervening Multi-Phase Absorption System Towards 3C 263
• Revealing the Milky Way's Hidden Circumgalactic Medium with the Cosmic Origins Spectrograph Quasar Database for Galactic Absorption Lines
• The Galactic Halo's O VI Resonance Line Intensity
• High ions towards white dwarfs: circumstellar line shifts and stellar temperature
• Evaluating the Morphology of the Local Interstellar Medium: Using New Data to Distinguish Between Multiple Discrete Clouds and a Continuous Medium
• Highly Ionized Plasma in the Halo of a Luminous Spiral Galaxy Near z=0.225
• Simulations of Mixed Morphology Supernova Remnants With Anisotropic Thermal Conduction
• Simulating Anisotropic Thermal Conduction in Supernova Remnants, Implications for the Interstellar Medium
• The Surprisingly Constant Strength of O VI Absorbers over Cosmic Time
• Probing feedback in protogalaxies: Multiphase gas in a DLA at z~2.4
• The origin of circumstellar features in the spectra of hot DA white dwarfs
• Pressure and Ionization Balances in the Circum-Heliospheric Interstellar Medium and the Local Bubble
• The Far Ultraviolet Spectroscopic Explorer Survey of OVI Emission in the Milky Way
• Simulating Gas Inflow at the Disk-Halo Interface
• Hunting for Metals Using XQ-100 Legacy Survey Composite Spectra
• Detection of highly ionized CIV gas within the Local Cavity
• Survey of O VI absorption in the Large Magellanic Cloud
• Physical Conditions of Five O VI Absorption Systems Towards PG $1522+101$
• Anisotropic Thermal Conduction in Supernova Remnants: Relevance to Hot Gas Filling Factors in the Magnetized ISM
• Detection of Low Metallicity Warm Plasma in a Galaxy Overdensity Environment at z ~ 0.2
• Revising the Local Bubble Model due to Solar Wind Charge Exchange X-ray Emission
• The OVI mystery: mismatch between X-ray and UV column densities
• Report from Sessions 1 and 3, including the Local Bubble Debate
• On the discrepancy between the X-ray and UV absorption measurements of OVI in the local ISM
• The nearby interstellar medium towards alpha Leo -- UV observations and modeling of a warm cloud within hot gas
• OVI Emission From the Supernovae-regulated Interstellar Medium: Simulation Vs Observation
• The distribution and kinematics of interstellar O~{\small VI} in the Milky Way}
• Hot Gas in the Galactic Thick Disk and Halo Near the Draco Cloud
• O~{\small VI} absorption in the Milky Way along the Large Magellanic Cloud lines of sight