2010/08/05 by C. S. Buemi, G. Umana, C. Trigilio +3 · 1 citation
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.1088/0004-637x/721/2/1404
published as ApJ 721 (2010) 1404-1411 · 26 pages, 8 figures. Accepted for publication in The Astrophysical Journal
arxiv created 2010/08/05 · openalex publication_date 2010/09/09 · arxiv updated 2010/09/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
High spatial and sensitivity images of the Luminous Blue Variable IRAS 18576+0341 were obtained using the mid-infrared imager VISIR at the Very Large Telescope and the Very Large Array interferometer. The resulting mid-infrared continuum maps show a similar clumpy and approximately circular symmetric nebula, which contrasts sharply with the asymmetry that characterizes the ionized component of the envelope, as evidenced from the radio and [Ne ii ] line images obtained with comparable spatial resolution. In particular, there is excellent overall agreement between the 12.8 μm map and the radio images, consistent with free–free emission from circumstellar ionized material surrounding a central stellar wind. The color temperature and optical depth maps obtained from mid-infrared images show only slight fluctuations, suggesting quite uniform dust characteristics over the dust shell. We explore various possibilities to understand the cause of the different morphology of the dusty and gaseous component of the circumstellar envelope which are compatible with the observations.