Spectrum formation in supernovae - Numerical techniques Export

@article{citeulike:2794854, abstract = {The study combines several novel techniques for spectrum simulation in the Eddington computer program which solves the comoving frame equation of transfer coupled with the statistical and radiative equilibrium equations. One of these is a generalization of the accelerated lambda iteration (ALI) scheme to include an approximate frequency-derivative operator. This greatly enhances the convergence rate of ALI in optically thick, high-velocity shear flows. Another is a partial linearization technique which is capable of efficiently solving a very large number of rate equations on a moderately sized computer. An expansion opacity and emissivity approximation is derived which makes it possible to determine the effect on the transfer and statistical equilibrium of a very large number of lines not explicitly represented in the frequency grid and additionally to treat line-blanketing from species not explicitly included in the rate equations. The utility of these techniques is illustrated with models of two supernovae.}, author = {Eastman, R. G. and Pinto, P. A.}, citeulike-article-id = {2794854}, citeulike-linkout-0 = {http://dx.doi.org/10.1086/172957}, citeulike-linkout-1 = {http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1993ApJ...412..731E}, doi = {10.1086/172957}, journal = {Astrophys. J.}, keywords = {analysis, astrophysics, computational, equations, equilibrium, functions, line, radiative, spectra, statistical, stellar, supernovae, transfer}, month = {August}, pages = {731--751}, posted-at = {2008-05-13 13:21:08}, priority = {2}, title = {Spectrum formation in supernovae - Numerical techniques}, url = {http://dx.doi.org/10.1086/172957}, volume = {412}, year = {1993} }

TY - JOUR ID - citeulike:2794854 L3 - citeulike-article-id:2794854 N2 - The study combines several novel techniques for spectrum simulation in the Eddington computer program which solves the comoving frame equation of transfer coupled with the statistical and radiative equilibrium equations. One of these is a generalization of the accelerated lambda iteration (ALI) scheme to include an approximate frequency-derivative operator. This greatly enhances the convergence rate of ALI in optically thick, high-velocity shear flows. Another is a partial linearization technique which is capable of efficiently solving a very large number of rate equations on a moderately sized computer. An expansion opacity and emissivity approximation is derived which makes it possible to determine the effect on the transfer and statistical equilibrium of a very large number of lines not explicitly represented in the frequency grid and additionally to treat line-blanketing from species not explicitly included in the rate equations. The utility of these techniques is illustrated with models of two supernovae. JF - Astrophys. J. EP - 751 TI - Spectrum formation in supernovae - Numerical techniques VL - 412 SP - 731 KW - analysis KW - astrophysics KW - computational KW - equations KW - equilibrium KW - functions KW - line KW - radiative KW - spectra KW - statistical KW - stellar KW - supernovae KW - transfer AU - Eastman, RG AU - Pinto, PA PY - 1993/August// UR - http://dx.doi.org/10.1086/172957 ER -