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We attempt to constrain the physical properties of the inner, gaseous disk ofthe Herbig Be star BD+65 1637 using non-LTE, circumstellar disk codes andobserved spectra (3700 to 10,500 \r{A}) from the ESPaDOnS instrument on CFHT.The photoionizing radiation of the central star is assumed to be the solesource of input energy for the disk. We model optical and near-infraredemission lines that are thought to form in this region using standardtechniques that have been successful in modeling the spectra of Classical Bestars. By comparing synthetic line profiles of hydrogen, helium, iron andcalcium with the observed line profiles, we try to constrain the geometry,density structure, and kinematics of the gaseous disk. Reasonable matches havebeen found for all line profiles individually; however, no disk density modelbased on a single power-law for the equatorial density was able tosimultaneously fit all of the observed emission lines. Amongst the emissionlines, the metal lines, especially the Ca II IR triplet, seem to require higherdisk densities than the other lines. Excluding the Ca II lines, a model inwhich the equatorial disk density falls as $10^{-10} (R_{*}/R)^3 g\,cm^{-3}$seen at an inclination of 45{\deg} for a $50\,R_{*}$ disk provides reasonablematches to the overall line shapes and strengths. The Ca II lines seem torequire a shallower drop off as $10^{-10} (R_{*}/R)^2 g\,cm^{-3}$ to matchtheir strength. More complex disk density models are likely required to refinethe match to the BD+65 1637 spectrum.

Photoionization Models of the Inner Gaseous Disk of the Herbig Be Star BD+65 1637