In Search of an Interface between Warm and Hot Gas within the Local Bubble
arXiv:2009.00677 · doi:10.3847/1538-4357/abb1ac
Abstract
We have examined UV spectra recorded by the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope for three stars, HD32309, 41 Ari, and ~Tel, that are located well inside the boundary of the Local Hot Bubble in our search for absorption features of Si IV, C IV, and N V that could reveal the presence of an interface between the local warm ( K) neutral medium and a more distant hot ( K) interstellar medium. In all cases, we failed to detect such ions. Our most meaningful upper limit is that for log N(C IV)< 11.86 toward HD32309, which is below the expectation for a sight line that penetrates either a conductive/evaporative interface or a turbulent mixing layer. We offer conjectures on the reasons for these negative results in terms of either a suppression of a conductive layer caused by the shielding of the local cloud by other clouds, which may make it more difficult for us to sense discrete absorption features from gases at intermediate temperatures, or by the presence of a tangential magnetic field at most locations on the surface of the local cloud.
arXiv comment14 pages, 1 figure, accepted for publication in the Astrophysical Journal
References in corpus (42)
- A Unified Representation of Gas-Phase Element Depletions in the Interstellar Medium
- The Structure of the Local Interstellar Medium V: Electron Densities
- 3D maps of the local ISM from inversion of individual color excess measurements
- Stellar Lyman-alpha Emission Lines in the Hubble Space Telescope Archive: Intrinsic Line Fluxes and Absorption from the Heliosphere and Astrospheres
- The origin of the Local Bubble
- Multiphase Gas and the Fractal Nature of Radiative Turbulent Mixing Layers
- New 3-D gas density maps of NaI and CaII interstellar absorption within 300pc
- The Far Ultraviolet Spectroscopic Explorer Survey of OVI Absorption in the Disk of the Milky Way
- The Ionization of Nearby Interstellar Gas
- The Structure of the Local Interstellar Medium. III. Temperature and Turbulence
- 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
- Evidence for Nearby Supernova Explosions
- Signatures of a two million year old supernova in the spectra of cosmic ray protons, antiprotons and positrons
- Simulations of radiative turbulent mixing layers
- The origin of the young stellar population in the solar neighborhood - a link to the formation of the Local Bubble?
- The origin of the 'local' 1/4 keV X-ray flux in both charge exchange and a hot bubble
- The Structure of the Local Hot Bubble
- Numerical Study of Turbulent Mixing Layers with Non-Equilibrium Ionization Calculations
- Inner edges of compact debris disks around metal-rich white dwarfs
- Characterizing Transition Temperature Gas in the Galactic Corona
- Evidence for an external origin of heavy elements in hot DA white dwarfs
- Local clouds: ionization, temperatures, electron densities and interfaces, from GHRS and IMAPS spectra of epsilon Canis Majoris
- Heavy element abundance patterns in hot DA white dwarfs
- Simulations of High-Velocity Clouds. I. Hydrodynamics and High-Velocity High Ions
- Charting the Interstellar Magnetic Field causing the Interstellar Boundary Explorer (IBEX) Ribbon of Energetic Neutral Atoms
- 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
- The interstellar cloud surrounding the Sun: a new perspective
- Circumstellar features in hot DA white dwarfs
- Fundamental Properties of the Highly Ionized Plasmas in the Milky Way
- Numerical Simulations of Supernova Remnant Evolution in a Cloudy Interstellar Medium
- OVI, NV and CIV in the Galactic Halo: II. Velocity-Resolved Observations with Hubble and FUSE
- O vi in the local interstellar medium
- High ions towards white dwarfs: circumstellar line shifts and stellar temperature
- Atomic data for S II - Toward Better Diagnostics of Chemical Evolution in High-redshift Galaxies
- Origins of the Highly Ionized Gas along the Line of Sight towards HD 116852
- On the Origin of the High-Ionization Intermediate-Velocity Gas Toward HD 14434
- High-Resolution Spectroscopy of G191-B2B in the Extreme Ultraviolet
- A High Spectral Resolution Study of the Soft X-ray Background with the X-ray Quantum Calorimeter
- Detection of highly ionized CIV gas within the Local Cavity
- Solar Wind Charge Exchange contribution to the ROSAT All Sky Survey Maps
- Simulations of High-Velocity Clouds. II. Ablation from High-Velocity Clouds as a Source of Low-Velocity High Ions