B[e] Supergiants' Circumstellar Environment: Disks or Rings?

KRAUS, M.; ARIAS, M. L.; MARAVELIAS, G.; ARET, A.; CIDALE, L.; BORGES FERNANDES, M.

Praga

Congreso; The B[e] Phenomenon: Forty Years of Studies; 2016

IAU

B[e] Supergiants are a phase in the evolution of some massive starsfor which we have observational evidence but no predictions by any stellar evolution model. The mass-loss during this phase creates a complex circumstellar environment with atomic, molecular, and dust regions usually found in rings or disk-like structures.However, the detailed structure and the formation of the circumstellar environment are not well-understood, requiring further investigation. To address that we initiated an observing campaign to obtain a homogeneous set of high-resolution spectra in both the optical and NIR (using MPG-ESO/FEROS, GEMINI/Phoenix and VLT/CRIRES, respectively). We monitor a number of Galactic B[e] Supergiants, for which we examined the [OI] and [CaII] emission lines and the bandheads of the CO and SiO molecules to probe the structure and the kinematics of their formation regions. We find that the emission from each tracer forms either in a single or in multiple equatorial rings.