The distribution and kinematics of interstellar O vi in the Milky Way

2016/10/04 by R. Sarma, Rathin Sarma, Amit Pathak +4
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Classical mechanics #Galaxy #Interstellar medium #Kinematics #Milky Way #Physics #Stellar kinematics #Stellar, planetary, and galactic studies #astro-ph.GA

paper · pdf · doi:10.1093/mnras/stw2557

6 figures, 3 tables, accepted for publication in MNRAS

arxiv created 2016/10/04 · openalex publication_date 2016/10/11 · openalex created_date 2016/10/14 · arxiv updated 2016/12/07 · openalex updated_date 2026/08/05

Abstract

We present the results of a survey of interstellar O vi absorption in the Milky Way (MW) towards 69 stars in the Large Magellanic Cloud obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). The integrated MW O vi column densities log N(O vi) are in the range from 13.68 to 14.73 with a mean of 14.26|_-0.09^+0.07| atoms cm−2. The O vi exponential scale height is found to be 2.28 ± 1.06 kpc. The O vi column density correlates with the Doppler parameter b. The O vi velocity dispersion ranges from 14.0 to 91.6 with an average value of 62.7 km s−1. These high values of the velocity dispersion reveal the effect of turbulence, multiple velocity components and collision on broad O vi profiles. There is a significant variation of the O vi column density on all scales studied (0| _.^∘|0025–6| _.^∘|35). The smallest scale for which O vi column density variations has been found is Δθ ∼ 9 arcsec. A comparison of the O vi velocity profiles with Fe ii indicates the presence of intermediate-velocity cloud and/or high-velocity cloud components in the O vi absorption.

Citations

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