Composite grains: Application to circumstellar dust

Authors

  • D. B. Vaidya ICCSIR,Ahmedabad India
  • R. Gupta

DOI:

https://doi.org/10.1478/C1V89S1P088

Abstract

Using the discrete dipole approximation (DDA) we calculate the absorption efficiency of the composite grain, made up of a host silicate spheroid and inclusions of graphite, in the spectral region 5.0-25.0 μm. We study the absorption as a function of the
volume fraction of the inclusions. In particular, we study the variation in the 10.0 μm and 18.0 μm emission features with the volume fraction of the inclusions. Using the extinction efficiencies, of the composite grains we calculate the infrared fluxes at several dust temperatures and compare the model curves with the observed infrared emission curves (IRAS-LRS), obtained for circumstellar dust shells around oxygen rich M-type stars.

Author Biography

  • D. B. Vaidya, ICCSIR,Ahmedabad India
    ICCSIR , Academic Advisor
Mount Aetna from Taormina by Thomas Cole (1843)

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Published

2011-09-15

Issue

Vol 89, SUPPLEMENT NO 1 (2011): ELS XIII Conference

Section

Past Conference Papers

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