Nolte, J. ; Yang, B. H. ; el-Qadi, W. ; Fonseca dos Santos, S. ; Lee, T. G. ; Balakrishnan, N. ; Forrey, R. C. ; Stancil, P. C. ; Shaw, G. ; Abel, N. P. ; Porter, R. L. ; Quan, D. ; Ferland, G. J. ; Schultz, D. R. ; van Hoof, P. A. M.

published in Bulletin of the American Astronomical Society, 43, pp. 330.06 (2011)

Abstract: As most of the gas in the Universe is not in thermal equilibrium, accurate modeling and interpretation of observations requires understanding of a variety of collisional processes. Rate coefficients describing such processes can usually be measured and/or calculated, but the enormous enhancements in the spectral line resolution and sensitivity expected from ALMA, SOFIA, Herschel, and other FIR/submm telescopes place unquenchable demands on the collisional data. As a consequence, the construction of reliable collisional data sets for astrophysical/astrochemical modeling faces a number of challenges: i) Due to the voluminous quantity of required data, theory must provide the bulk of the results with experiment serving as benchmarks. ii) The accuracy of the scattering calculations are directly dependent on the reliability and availability of the quantum chemical data. iii) Database construction requires consistent and appropriate funding which is typically lacking. We review these issues in the context of our ongoing collaborative work on computations of rovibrational excitation of H_2, HD, CO, H_2O, CO_2, NH_3, and CH_4 due to H, He, and H_2 collisions and their role in the modeling of various astrophysical environments. This work was partially supported by NASA grants NNG05GD81G, NNG06GC94G, NNX07AP12G, and NNX10AD56G, and NSF grants PHY-0554794, PHY-0855470, PHY-0854838, and AST-0607733.

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