The discrete-dipole approximation and its application to interstellar graphite grains

Statistics – Computation

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

501

Computational Astrophysics, Cosmic Dust, Discrete Functions, Graphite, Interstellar Space, Absorption Cross Sections, Grain Size, Polarization (Waves), Radiative Transfer, Scattering Cross Sections

Scientific paper

The discrete dipole approximation (DDA), a flexible method for computing scattering of radiation by particles of arbitrary shape, is extended to incorporate the effects of radiative reaction and to allow for possible anisotropy of the dielectric tensor of the material. Formulas are given for the evaluation of extinction, absorption, scattering, and polarization cross sections. A simple numerical algorithm based on the method of conjugate gradients is found to provide an efficient and robust method for obtaining accurate solutions to the scattering problem. The method works well for absorptive, as well as dielectric, grain materials. Two validity criteria for the DDA are presented. The DDA is then used to compute extinction cross sections for spherical graphite grains and to calculate extinction cross sections for nonspherical graphite grains with three different geometries. It is concluded that the interstellar 2175 A extinction feature could be produced by small graphite grains which should have aspect ratios not far from unity.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The discrete-dipole approximation and its application to interstellar graphite grains does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The discrete-dipole approximation and its application to interstellar graphite grains, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The discrete-dipole approximation and its application to interstellar graphite grains will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1598191

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.