ar X iv : a st ro - p h / 05 06 40 6 v 1 1 7 Ju n 20 05 Debris Disk Radiative Transfer Simulation Tool ( DDS )

CPC: 1.3 Radiative Transfer PACS: 94.10.Gb-Absorption and scattering of radiation 97.21.+a-Pre-main sequence objects, young stellar objects and protostars 97.82.+k-Extrasolar planetary systems Abstract A WWW interface for the simulation of spectral energy distributions of optically thin dust configurations with an embedded radiative source is presented. The density distribution, radiative source, and dust parameters can be selected either from an internal database or defined by the user. This tool is optimized for studying cir-cumstellar debris disks where large grains (a grain ≫ 1µm) are expected to determine the far-infrared through millimeter dust reemission spectral energy distribution. The tool is available at Licensing provisions: none Computers: PC with Intel(R) XEON(TM) 2.80 GHz processor Operating systems under which the program has been tested: SUSE Linux 9.1 Programming language used: Fortran 90 (for the main program; furthermore Perl, CGI and HTML) Memory required to execute with typical data: 10 8 words No. of bits in a word: 8 No. of lines in distributed program, including test data, etc.: 9264 Keywords: Nature of physical problem Simulation of scattered light and thermal reemission in arbitrary optically dust distributions with spherical, homogeneous grains where the dust parameters (optical properties, sublimation temperature, grain size) and SED of the illuminat-ing/heating radiative source can be arbitrarily defined (example application: Wolf & Hillenbrand 2003). The program is optimized for studying circumstellar debris disks where large grains (i.e., with large size parameters) are expected to determine the far-infrared through millimeter dust reemission spectral energy distribution. Method of solution Calculation of the dust temperature distribution and dust reemission and scattering spectrum in the optically thin limit. Restrictions on the complexity of the problem 1) The approach to calculate dust temperatures and dust reemission spectra is only valid in the optically thin regime. The validity of this constraint is verified for each model during the runtime of the code. 2) The relative abundances of different grains can be arbitrarily chosen, but must be constant outside the dust sublimation region., i.e., the shape of the (arbitrary) radial dust density distribution outside the dust sublimation region is the same for 2 all grain sizes and chemistries. 3) The size of upload files (such as the dust density distribution, optical data of the dust grains, stellar spectral energy distribution, etc.) is limited (see http://aida28.mpia-hd.mpg.de/∼swolf/dds/ for current file size limits). However, the resulting limitation to the complexity of possible model definitions is marginal only. Typical running time 3 sec-30 …