Probing atmospheres and circumstellar environments of Be stars and evolved low mas...
| Full text | |
| Author(s): |
Silaj, J.
;
Jones, C. E.
;
Carciofi, A. C.
;
Escolano, C.
;
Okazaki, A. T.
;
Tycner, C.
;
Rivinius, T.
;
Klement, R.
;
Bednarski, D.
Total Authors: 9
|
| Document type: | Journal article |
| Source: | ASTROPHYSICAL JOURNAL; v. 826, n. 1 JUL 20 2016. |
| Web of Science Citations: | 4 |
| Abstract | |
A global disk oscillation implemented in the viscous decretion disk (VDD) model has been used to reproduce most of the observed properties of the well known Be star zeta Tau. 48 Librae shares several similarities with zeta Tau-they are both early-type Be stars, display shell characteristics in their spectra, and exhibit cyclic V/R variations-but has some marked differences as well, such as a much denser and more extended disk, a much longer V/R cycle, and the absence of the so-called triple-peak features. We aim to reproduce the photometric, polarimetric, and spectroscopic observables of 48 Librae with a self-consistent model, and to test the global oscillation scenario for this target. Our calculations are carried out with the three-dimensional NLTE radiative transfer code HDUST. We employ a rotationally deformed, gravity-darkened central star surrounded by a disk whose unperturbed state is given by the VDD model. A two-dimensional global oscillation code is then used to calculate the disk perturbation and superimpose it on the unperturbed disk. A very good, self-consistent fit to the time-averaged properties of the disk is obtained with the VDD. The calculated perturbation has a period P = 12 years, which agrees with the observed period, and the behavior of the V/R cycle is well reproduced by the perturbed model. The perturbed model improves the fit to the photometric data and reproduces some features of the observed spectroscopic data. Some suggestions to improve the synthesized spectroscopy in a future work are given. (AU) | |
| FAPESP's process: | 15/17967-7 - Viscous decretion disks: theory and observations |
| Grantee: | Alex Cavaliéri Carciofi |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 11/51720-8 - Probing the physical characteristics of the disks surrounding Be stars |
| Grantee: | Alex Cavaliéri Carciofi |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 09/54006-4 - A computer cluster for the Astronomy Department of the University of São Paulo Institute of Astronomy, Geophysics and Atmospheric Sciences and for the Cruzeiro do Sul University Astrophysics Center |
| Grantee: | Elisabete Maria de Gouveia Dal Pino |
| Support Opportunities: | Multi-user Equipment Program |