The Hα profiles of Be shell stars

Silaj, J.; Jones, C. E.; Sigut, T. A. A.; Tycner, C.

doi:10.1088/0004-637X/795/1/82

Title: The Hα profiles of Be shell stars

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Abstract

A new set of theoretical Hα emission line profiles of Be stars has been computed using the code BERAY, which solves the transfer equation along a series of rays passing through the star+disk system, representing an improved treatment over earlier work done by the authors. The new profiles were compared with the previous work, and general trends (such as line profile shapes and correlations between line equivalent widths as a function of initial density ρ{sub 0} and power law index n) were recovered. Additionally, BERAY was employed to model the spectra of eight well-known Be shell stars. Some degeneracy was found in the choice of model parameters, highlighting the need to employ alternate observables to constrain the models. However, the inclination angle of the model seemed relatively insensitive to the choices of other parameters, and we show that, with our models, only a very small range of inclination angles can adequately reproduce the observations. Five of our eight targets were found to have inclination angles of 70° or higher, and two more were found to have inclination angles of 67° and 65°. The observation of one target—4 Aquilae—could only be reproduced by models created at an inclination angle of approximatelymore » 45°.« less

Authors:

Silaj, J.; Jones, C. E.; Sigut, T. A. A. ^[1]; Tycner, C. ^[2]

Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, N6A 3K7 (Canada)
Department of Physics, Central Michigan University, Mt. Pleasant, MI 48859 (United States)

Publication Date:: Sat Nov 01 00:00:00 EDT 2014

OSTI Identifier:: 22370269

Resource Type:: Journal Article

Journal Name:: Astrophysical Journal

Additional Journal Information:: Journal Volume: 795; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X

Country of Publication:: United States

Language:: English

Subject:: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; COMPARATIVE EVALUATIONS; DENSITY; EMISSION; INCLINATION; SPECTRA; STARS

Citation Formats


                    Silaj, J., Jones, C. E., Sigut, T. A. A., and Tycner, C. The Hα profiles of Be shell stars.  United States: N. p., 2014. 
        Web.  doi:10.1088/0004-637X/795/1/82.

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                    Silaj, J., Jones, C. E., Sigut, T. A. A., & Tycner, C. The Hα profiles of Be shell stars.  United States.  https://doi.org/10.1088/0004-637X/795/1/82

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                    Silaj, J., Jones, C. E., Sigut, T. A. A., and Tycner, C. 2014.  
        "The Hα profiles of Be shell stars".  United States.  https://doi.org/10.1088/0004-637X/795/1/82.

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@article{osti_22370269,

  title        = {The Hα profiles of Be shell stars},

  author       = {Silaj, J. and Jones, C. E. and Sigut, T. A. A. and Tycner, C.},

  abstractNote = {A new set of theoretical Hα emission line profiles of Be stars has been computed using the code BERAY, which solves the transfer equation along a series of rays passing through the star+disk system, representing an improved treatment over earlier work done by the authors. The new profiles were compared with the previous work, and general trends (such as line profile shapes and correlations between line equivalent widths as a function of initial density ρ{sub 0} and power law index n) were recovered. Additionally, BERAY was employed to model the spectra of eight well-known Be shell stars. Some degeneracy was found in the choice of model parameters, highlighting the need to employ alternate observables to constrain the models. However, the inclination angle of the model seemed relatively insensitive to the choices of other parameters, and we show that, with our models, only a very small range of inclination angles can adequately reproduce the observations. Five of our eight targets were found to have inclination angles of 70° or higher, and two more were found to have inclination angles of 67° and 65°. The observation of one target—4 Aquilae—could only be reproduced by models created at an inclination angle of approximately 45°.},

  doi          = {10.1088/0004-637X/795/1/82},

  url          = {https://www.osti.gov/biblio/22370269},
  journal      = {Astrophysical Journal},

  issn         = {0004-637X},

  number       = 1,

  volume       = 795,

  place        = {United States},

  year         = {Sat Nov 01 00:00:00 EDT 2014},

  month        = {Sat Nov 01 00:00:00 EDT 2014}

}

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