BAYESIAN INFERENCE OF SOLAR AND STELLAR MAGNETIC FIELDS IN THE WEAK-FIELD APPROXIMATION

doi:10.1088/0004-637X/731/1/27

Title: BAYESIAN INFERENCE OF SOLAR AND STELLAR MAGNETIC FIELDS IN THE WEAK-FIELD APPROXIMATION

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Abstract

The weak-field approximation is one of the simplest models that allows us to relate the observed polarization induced by the Zeeman effect with the magnetic field vector present on the plasma of interest. It is usually applied for diagnosing magnetic fields in the solar and stellar atmospheres. A fully Bayesian approach to the inference of magnetic properties in unresolved structures is presented. The analytical expression for the marginal posterior distribution is obtained, from which we can obtain statistically relevant information about the model parameters. The role of a priori information is discussed and a hierarchical procedure is presented that gives robust results that are almost insensitive to the precise election of the prior. The strength of the formalism is demonstrated through an application to IMaX data. Bayesian methods can optimally exploit data from filter polarimeters given the scarcity of spectral information as compared with spectro-polarimeters. The effect of noise and how it degrades our ability to extract information from the Stokes profiles is analyzed in detail.

Authors:

Asensio Ramos, A., E-mail: aasensio@iac.es ^[1]; Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife ^[2]

Instituto de Astrofisica de Canarias, 38205, La Laguna, Tenerife (Spain)
(Spain)

Publication Date:: Sun Apr 10 00:00:00 EDT 2011

OSTI Identifier:: 21574784

Resource Type:: Journal Article

Journal Name:: Astrophysical Journal

Additional Journal Information:: Journal Volume: 731; Journal Issue: 1; Other Information: DOI: 10.1088/0004-637X/731/1/27; Journal ID: ISSN 0004-637X

Country of Publication:: United States

Language:: English

Subject:: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; DATA ANALYSIS; MAGNETIC FIELDS; PHOTOSPHERE; SOLAR ATMOSPHERE; ATMOSPHERES; CALCULATION METHODS; STELLAR ATMOSPHERES

Citation Formats


                    Asensio Ramos, A., E-mail: aasensio@iac.es, and Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife. BAYESIAN INFERENCE OF SOLAR AND STELLAR MAGNETIC FIELDS IN THE WEAK-FIELD APPROXIMATION.  United States: N. p., 2011. 
        Web.  doi:10.1088/0004-637X/731/1/27.

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                    Asensio Ramos, A., E-mail: aasensio@iac.es, & Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife. BAYESIAN INFERENCE OF SOLAR AND STELLAR MAGNETIC FIELDS IN THE WEAK-FIELD APPROXIMATION.  United States.  https://doi.org/10.1088/0004-637X/731/1/27

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                    Asensio Ramos, A., E-mail: aasensio@iac.es, and Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife. 2011.  
        "BAYESIAN INFERENCE OF SOLAR AND STELLAR MAGNETIC FIELDS IN THE WEAK-FIELD APPROXIMATION".  United States.  https://doi.org/10.1088/0004-637X/731/1/27.

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@article{osti_21574784,

  title        = {BAYESIAN INFERENCE OF SOLAR AND STELLAR MAGNETIC FIELDS IN THE WEAK-FIELD APPROXIMATION},

  author       = {Asensio Ramos, A., E-mail: aasensio@iac.es and Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife},

  abstractNote = {The weak-field approximation is one of the simplest models that allows us to relate the observed polarization induced by the Zeeman effect with the magnetic field vector present on the plasma of interest. It is usually applied for diagnosing magnetic fields in the solar and stellar atmospheres. A fully Bayesian approach to the inference of magnetic properties in unresolved structures is presented. The analytical expression for the marginal posterior distribution is obtained, from which we can obtain statistically relevant information about the model parameters. The role of a priori information is discussed and a hierarchical procedure is presented that gives robust results that are almost insensitive to the precise election of the prior. The strength of the formalism is demonstrated through an application to IMaX data. Bayesian methods can optimally exploit data from filter polarimeters given the scarcity of spectral information as compared with spectro-polarimeters. The effect of noise and how it degrades our ability to extract information from the Stokes profiles is analyzed in detail.},

  doi          = {10.1088/0004-637X/731/1/27},

  url          = {https://www.osti.gov/biblio/21574784},
  journal      = {Astrophysical Journal},

  issn         = {0004-637X},

  number       = 1,

  volume       = 731,

  place        = {United States},

  year         = {Sun Apr 10 00:00:00 EDT 2011},

  month        = {Sun Apr 10 00:00:00 EDT 2011}

}

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https://doi.org/10.1088/0004-637X/731/1/27

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