2-Dust Code Home

2-Dust Code Public Distribution Page
Toshiya Ueta (NASA Ames Research Center/SOFIA project) &  Margaret Meixner (Space Telescope Science Institute)

  • What is 2-Dust?
  • Latest Distribution Pack
  • Related Publications
  • 2-Dust on Linux
  • The Logo
  • Acknowledgements
    What is 2-Dust ("two-dust") ?


    2-Dust is a general-purpose dust radiative transfer code for an axisymmetric system written in Fortran 90. Its development is motivated by the recent increasing availability of high-resolution images of circumstellar dust shells at various wavelengths, especially in the mid-IR ranges (N and Q bands).

    This code solves the equation of radiative transfer following the principle of long characteristic in a 2-D polar grid, while considering a 3-D radiation field at each grid point. A solution is sought through an iterative scheme in which self-consistency of the solution is achieved by requiring a global luminosity constancy throughout the shell.

    The main focus of the code is to obtain insights on
    (1) the global energetics of dust grains in the shell
    (2) the 2-D projected morphologies of the shell that are strongly dependent on the mixed effects of the axisymmetric dust distribution and inclination angle.

    Meanwhile, we allowed sufficient flexibility so that the code can be used to model a variety of axisymmetric astronomical dust systems. For example, users can use his/her own density distribution function as a fortran function (see an example from Ueta & Meixner 2003). Also, the dust opacities are calculated through Mie theory from the user-given size distribution and optical constants (as "n & k" values) of the dust grains.


    This code is publicly available and free to use as long as the code paper, "2-Dust: A Dust Radiative Transfer Code for an Axisymmetric System" by Ueta, T., & Meixner, M. (2003, Astrophysical Journal, 586, 1338), is cited as a reference in work using the code. If you would like to keep informed on future updates, please contact Ueta (toshiya_ueta@fastmail.us) to be included in the mailing list.

    If you need assistance with using the code, you can contact Ueta (toshiya_ueta@fastmail.us) or Meixner (meixner@stsci.edu) to discuss possible collaborative projects.

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    Latest Distribution Pack

    The Code:
    This tar file contains all components of the code (subroutines) and a very simple Makefile.
    Revision History
    Test Model Packs:
    This tar file contains the final model of an O-rich post-AGB star, IRAS 17436+5003 (HD 161796) presented in Meixner, Ueta, Bobrowsky, &  Speck 2002, ApJ, 571, 936. This is provided for you to play with the code without having to figure out the input parameters. But, the input parameters follow rather old version of the code.

    This tar file contains a model of a C-rich post-AGB star, IRAS 07134+1005 (HD 56126) presented in Meixner, Zalucha, Ueta, Fong, &  Justtanont 2004, ApJ, 614 371. The input parameters follow the latest format.

    Users' Manual:
    The latest Users' Manual for 2-Dust.
    Code Paper

    For detailed explanation of the code, please read
    "2-Dust: A Dust Radiative Transfer Code for an Axisymmetric System" by Ueta, T., &  Meixner, M. (2003, ApJ, 586, 1338).

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    Related Publications
    Code Paper

    "2-Dust: a Radiative Transfer Code for an Axisymmetric System"
    Ueta, T., &  Meixner, M.
    2003, ApJ, 586, 1338 (ApJ online)
    Results with the Code / Hints for Practical Use

    "The Molecular and Dust Envelope of HD 56126""
    Meixner, M., Zalucha, A., Ueta, T., Fong, D., &  Justtanont, K.
    2004, ApJ, 614, 371 (ADS link)

    "The Dust Ring of LBV Candidate HD 168625: Infrared Observations and Model Calculations"
    O'Hara, T. B., Meixner, M., Speck, A. K., Ueta, T., &  Bobrowsky, M.
    2003, ApJ, 598, 1255 (ADS link)

    "Two Subclasses of Proto-Planetary Nebulae: Model Calculations"
    Meixner, M., Ueta, T., Bobrowsky, M., &  Speck, A. K.
    2002, ApJ, 571, 936 (ADS link)

    "Subarcsecond Mid-IR Structure of the Dust Shell around IRAS 22272+5435"
    Ueta, T., Meixner, M., Hinz, P. M., Hoffmann, W. F., Brandner, W., Dayal, A., Deutsch, L. K., Fazio, G. G., &  Hora, J. L.
    2001, ApJ, 557, 831 (ADS link)

    "Discovery of an Extended Dust Emission around IRAS 18576+0341 (AFGL 2298): a New Luminous Blue Variable Candidate?"
    Ueta, T., Meixner, M., Dayal, A., Deutsch, L. K., Fazio, G. G., Hora, J. L., &  Hoffmann, W. F.
    2001, ApJ, 548, 1020 (ADS link)

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    2-Dust on Linux

    There is a Fortran compiler for Linux from Intel (free for non-commercial use). For those interested, click here.

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    The Logo

    LaTeX definitions of the logo
    (1) The "official" version: 2-Dust
    $\raisebox{0.3ex}{\mbox{{\sc 2-D}}}\kern-0.55em%
    \raisebox{-0.3ex}{\mbox{{\sc Dust}}}$}

    USAGE: {\twodust}

    (2) The "one-line" version: 2-Dust
    {\bf 2-D}{\sc ust}}

    USAGE: {\twodustalt}

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    The 2-Dust code developement was supported by NSF Career Award grant AST 97-33697.

    Back to Toshiya Ueta's Research page.

    Comments to toshiya_ueta@fastmail.us