This directory includes:

ext.f - A Fortran code which calculates extinction curves for given
input parameters

Gra_81, SiC_81, suvSil_81 - Input data files for ext.f

mrn.ps, other.ps - Example plots for various outputs generated by ext.f


To run the code one needs to input the following free parameters:

Composition - Graphite+Silicate, Graphite+Silicon Carbide (SiC)
fsil - the relative abundances of Silicate, or SiC, to Graphite
alpha - the slope of the power-law size distribution
R_min - minimum grain radius 0.001 microns
R_max - maximum grain radius 10.0 microns
fmas - dust/gas mass ratio

The program prompts you for these input parameter. There is a shortcut
for calculating the "standard" MRN dust model.

The program outputs to unit 7:
1/lambda (mic^-1), A_lambda/A_v  (the "traditional" extinction curve).

and to unit 8:
lambda (mic), tau_tot, tau_abs(Gra), tau_sca(Gra), tau_abs(Sil),
tau_sca(Sil), g=<cos theta_scat>


The program requires the three input files:

Gra_81,  SiC_81,  suvSil_81 .

These are taken from Bruce Draine's Home Page at:

http://www.astro.princeton.edu/~draine/dust/dust.diel.html

Please credit the relevant papers from the above site when using this
program.