INVESTIGATING THE CIRCUMSTELLAR DISK OF THE Be SHELL STAR 48 LIBRAE

Autor(es)

Silaj, J. ; Jones, C. E. ; Carciofi, A. C. ; Escolano, C. ; Okazaki, A. T. ; Tycner, C. ; Rivinius, T. ; Klement, R. ; Bednarski, D.

• Tipo de documento: Artigo Científico
• Fonte: ASTROPHYSICAL JOURNAL; v. 826, n. 1 JUL 20 2016.
• Citações Web of Science: 4

Resumo

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)

• Processo FAPESP: 15/17967-7 - Discos de decréscimo viscoso: teoria e observações
• Beneficiário: Alex Cavaliéri Carciofi
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/51720-8 - Probing the physical characteristics of the disks surrounding Be stars
• Beneficiário: Alex Cavaliéri Carciofi
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 09/54006-4 - Um cluster de computadores para o Departamento de Astronomia do IAG-USP e para o Núcleo de Astrofísica da UNICSUL
• Beneficiário: Elisabete Maria de Gouveia Dal Pino
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários