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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Multitechnique testing of the viscous decretion disk model I. The stable and tenuous disk of the late-type Be star beta CMi

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Autor(es):
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Klement, R. [1] ; Carciofi, A. C. [2] ; Rivinius, Th. [3] ; Panoglou, D. [2] ; Vieira, R. G. [2] ; Bjorkman, J. E. [4] ; Stefl, S. ; Tycner, C. [5] ; Faes, D. M. [2] ; Korcakova, D. [1] ; Mueller, A. [3] ; Zavala, R. T. [6] ; Cure, M. [7]
Número total de Autores: 13
Afiliação do(s) autor(es):
[1] Charles Univ Prague, Astron Inst Charles, CR-18000 Prague 8 - Czech Republic
[2] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508900 Sao Paulo, SP - Brazil
[3] European Org Astron Res Southern Hemisphere, Santiago 19 - Chile
[4] Univ Toledo, Dept Phys & Astron, Ritter Observ, Toledo, OH 43606 - USA
[5] Cent Michigan Univ, Dept Phys, Mt Pleasant, MI 48859 - USA
[6] US Naval Observ, Flagstaff, AZ 86001 - USA
[7] Univ Valparaiso, Fac Ciencias, Inst Fis & Astron, Valparaiso 5030 - Chile
Número total de Afiliações: 7
Tipo de documento: Artigo Científico
Fonte: Astronomy & Astrophysics; v. 584, DEC 2015.
Citações Web of Science: 13
Resumo

Context. The viscous decretion disk (VDD) model is able to explain most of the currently observable properties of the circumstellar disks of Be stars. However, more stringent tests, focusing on reproducing multitechnique observations of individual targets via physical modeling, are needed to study the predictions of the VDD model under specific circumstances. In the case of nearby, bright Be star beta CMi, these circumstances are a very stable low-density disk and a late-type (B8Ve) central star. Aims. The aim is to test the VDD model thoroughly, exploiting the full diagnostic potential of individual types of observations, in particular, to constrain the poorly known structure of the outer disk if possible, and to test truncation effects caused by a possible binary companion using radio observations. Methods. We use the Monte Carlo radiative transfer code HDUST to produce model observables, which we compare with a very large set of multitechnique and multiwavelength observations that include ultraviolet and optical spectra, photometry covering the interval between optical and radio wavelengths, optical polarimetry, and optical and near-IR (spectro) interferometry. Results. A parametric VDD model with radial density exponent of n = 3.5, which is the canonical value for isothermal flaring disks, is found to explain observables typically formed in the inner disk, while observables originating in the more extended parts favor a shallower, n = 3.0, density falloff. Theoretical consequences of this finding are discussed and the outcomes are compared with the predictions of a fully self-consistent VDD model. Modeling of radio observations allowed for the first determination of the physical extent of a Be disk (35(-5)(+10) stellar radii), which might be caused by a binary companion. Finally, polarization data allowed for an indirect measurement of the rotation rate of the star, which was found to be W greater than or similar to 0.98, i.e., very close to critical. (AU)

Processo FAPESP: 13/16801-2 - Modelagem da formação e evolução de discos estelares gasosos de acreção e decreção
Beneficiário:Despina Panoglou
Linha de fomento: Bolsas no Brasil - Pós-Doutorado
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
Linha de fomento: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
Processo FAPESP: 12/20364-4 - Além da sobrevivência da poeira: as regiões internas de discos protoplanetários
Beneficiário:Rodrigo Georgetti Vieira
Linha de fomento: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 10/19060-5 - Uma visão interferométrica de discos de estrelas quentes
Beneficiário:Daniel Moser Faes
Linha de fomento: Bolsas no Brasil - Doutorado