Highly ionized plasma in the Large Magellanic Cloud: evidence for outflows and a possible galactic wind

2007/02/16 by Nicolas Lehner, N. Lehner, J. Christopher Howk +1 · 58 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Galactic halo #Galaxy #Halo #Hubble space telescope #Intergalactic travel #Ion #Ionization #Large Magellanic Cloud #Milky Way #Physics #Redshift #Space Telescope Imaging Spectrograph #Stars #Stellar, planetary, and galactic studies #astro-ph

paper · pdf · doi:10.1111/j.1365-2966.2007.11631.x

published in Monthly Notices of the Royal Astronomical Society 377(2), 687-704 (Oxford University Press) · Accepted for publication in the MNRAS

arxiv created 2007/02/16 · openalex publication_date 2007/03/28 · arxiv updated 2010/05/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

Based on an analysis of the interstellar highly ionized species C iv, Si iv, N v and O vi observed in the Far Ultraviolet Spectroscopic Explorer (FUSE) and Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) E140M spectra of four hot stars in the Large Magellanic Cloud (LMC), we find evidence for a hot LMC halo fed by energetic outflows from the LMC disc and even possibly an LMC galactic wind. Signatures for such outflows are the intermediate- and high-velocity components (vLSR≳ 100 km s−1) relative to the LMC disc observed in the high- and low-ion absorption profiles. The stellar environments produce strong, narrow (T≲ 2 × 104 K) components of C iv and Si iv associated with the LMC disc; in particular they are likely signatures of H ii regions and expanding shells. Broad components are observed in the profiles of C iv, Si iv and O vi with their widths implying hot, collisionally ionized gas at temperatures of a few times 105 K. There is a striking similarity in the O vi/C iv ratios for the broad LMC and high-velocity components, suggesting much of the material at vLSR≳ 100 km s−1 is associated with the LMC. The velocity of the high-velocity component is large enough to escape altogether the LMC, polluting the intergalactic space between the LMC and the Milky Way. The observed high-ion ratios of the broad LMC and high-velocity components are consistent with those produced in conductive interfaces; such models are also favoured by the apparent kinematically coupling between the high and the weakly ionized species.

Citations

• The Space Telescope Imaging Spectrograph Design
• CLOUDY 90: Numerical Simulation of Plasmas and Their Spectra

Cited by

• Demystifying Strange O VI Line Widths with Hydrodynamic Simulations
• New Interpretation for the Orientation of the LMC's Gaseous Arms B and E using ULLYSES
• On the Nature of Velocity Fields in High‐zGalaxies
• PROPERTIES AND ORIGIN OF THE HIGH-VELOCITY GAS TOWARD THE LARGE MAGELLANIC CLOUD
• The High‐Velocity Gas toward Messier 5: Tracing Feedback Flows in the Inner Galaxy
• High-ion absorption in seven GRB host galaxies at z = 2–4
• NUMERICAL STUDY OF TURBULENT MIXING LAYERS WITH NON-EQUILIBRIUM IONIZATION CALCULATIONS
• AHUBBLE SPACE TELESCOPESTUDY OF LYMAN LIMIT SYSTEMS: CENSUS AND EVOLUTION
• C IV absorption in damped and sub-damped Lyman-α systems
• The distribution and kinematics of interstellar O vi in the Milky Way
• THE EXTENSION OF THE TRANSITION TEMPERATURE PLASMA INTO THE LOWER GALACTIC HALO
• THE CONNECTION BETWEEN A LYMAN LIMIT SYSTEM, A VERY STRONG O VI ABSORBER, AND GALAXIES ATz∼ 0.203

Related

• PROPERTIES AND ORIGIN OF THE HIGH-VELOCITY GAS TOWARD THE LARGE MAGELLANIC CLOUD
• Interstellar O VI in the Large Magellanic Cloud
• The Truncated Circumgalactic Medium of the Large Magellanic Cloud
• The Gaseous Blowout of the 30 Doradus Starburst Region in the LMC
• Observations of a Magellanic Corona