An Interpolation Method for the Solution of NonLTE Line Transfer Problems
Abstract
Summary: Iterative procedures solving nonLTE line transfer problems through the integral equation approach require the calculation of monochromatic lambda operators. We outline a simple interpolation method that avoids the repeated evaluation of exponential integrals. Based on polynomial approximation of the source function, gaussian integration weights 0cm and divisions tm have to be calculated only once from the integral representation for a set of rpoints. While saving more than 3/4 of computing time, first solutions of multilevel line transfer problems indicate that the accuracy is comparable to other methods. Key words: nonLTE  line transfer  interpolation method (t) E,(t) dt = M mZ=i 0cmf(tm)
 Publication:

Astronomy and Astrophysics
 Pub Date:
 September 1973
 Bibcode:
 1973A&A....27..291G