2018/07/31 by Grigoris Maravelias, Michaela Kraus, Lydia S. Cidale +4 · 1 citation
Physics and Astronomy · #astro-ph.SR
paper · pdf · doi:10.1093/mnras/sty1747
27 pages, 13 figures, 4 tables. Published in MNRAS. Minor corrections in this version: (a) adding references in the text to Fig. 6, tables A6 and A8, and footnote 5, (b) adding/modifying the acknowledgments section
arxiv created 2018/09/04 · arxiv updated 2018/09/05
B[e] Supergiants are luminous evolved massive stars. The mass-loss during this phase creates a complex circumstellar environment with atomic, molecular, and dusty regions usually found in rings or disk-like structures. For a better comprehension of the mechanisms behind the formation of these rings, detailed knowledge about their structure and dynamics is essential. To address that, we obtained high-resolution optical and near-infrared spectra for 8 selected Galactic B[e] Supergiants, for which CO emission has been detected. Assuming Keplerian rotation for the disk, we combine the kinematics obtained from the CO bands in the near-IR with those obtained by fitting the forbidden emission [OI] λ5577, [OI] λλ6300,6363, and [CaII] λλ7291,7323 lines in the optical to probe the disk structure. We find that the emission originates from multiple ring structures around all B[e] Supergiants, with each one of them displaying a unique combination of rings regardless of whether the object is part of a binary system. The confirmed binaries display spectroscopic variations of their line intensities and profiles as well as photometric variability, whereas the ring structures around the single stars are stable.