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Multitechnique study of the B[e] supergiant RMC 82.
- Source :
-
Monthly Notices of the Royal Astronomical Society . Feb2024, Vol. 528 Issue 1, p122-140. 19p. - Publication Year :
- 2024
-
Abstract
- B[e] supergiants (sgB[e]) are rare objects whose evolutionary stage remains uncertain. Observationally, they display strong Balmer emission lines, infrared excess, and intrinsic polarization, indicating a non-spherical circumstellar envelope. We present a study of the sgB[e] RMC 82, using new spectropolarimetric data complemented by photometry from the ultraviolet (UV) to the mid-infrared. Our two-component model comprises a slow, dense equatorial wind wherein dust grains form and a fast polar wind. We applied the hdust radiative transfer code and Bayesian statistics to infer the parameters from a grid of 3240 pre-computed models. The model accurately reproduces the spectral energy distribution and polarized spectrum, but struggles to match the H α emission. Our results suggest a large mass-loss rate of |$6.6 \times 10^{-6}\, \mathrm{{\rm M}_{\odot }\, yr^{-1}\, sr^{-1}}$|. The dense wind is confined within an opening angle of 11°. The hottest dust grains are located at 277 R * with a temperature of 870 K. The dust grains are porous, with a density of 0.051 |$\rm {g\, cm^{-3}}$|. The central star was found to be significantly hotter than previous estimates (T eff =  |$27\, 000$| K). By comparing models with different components, we find that gas reprocesses a significant amount of UV radiation, shielding the dust. However, the dust also scatters UV photons back to the inner disc, increasing its temperature and H α emission. We conclude that self-consistent models, that account for the gas–dust interplay in the envelope, are essential for studying sgB[e] and similar objects. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00358711
- Volume :
- 528
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Monthly Notices of the Royal Astronomical Society
- Publication Type :
- Academic Journal
- Accession number :
- 175011090
- Full Text :
- https://doi.org/10.1093/mnras/stad3948