Meeting the Challenge of Webb - Spectroscopic Simulations of Star-Forming Regions and Active Galactic Nuclei

Meeting the Challenge of Webb - Spectroscopic Simulations of Star-Forming Regions, Active Galactic Nuclei, and the Intra-Cluster Medium Gary J. Ferland, UK Physics The IR window probes otherwise-hidden regions of extragalactic star-formation and AGN activity. The Webb Space Telescope will offer a unique perspective on this activity, with its high sensitivity and superb resolution. Central questions include following the role of feedback in the formation and evolution of galaxies, interactions with the surrounding intracluster medium, and their effects on the metagalactic background. The central theme in this proposal is the development of the theoretical tools needed to realize the diagnostic potential of the 0.6 to 5 m and 5 - 28 m spectroscopic windows offered by Webb, with correspondingly longer wavelengths at higher redshift. The particular regimes to be addressed include the physics of dust emission in gas rich environments, ionic and molecular emission in an evolving environment with a mix of star formation and AGN activity, all in an environment that is optically thick to portions of the radiation field. The gas and dust are far from equilibrium, so their spectra depends on detailed atomic, molecular, and solid state physics. This is a complication, but is also why quantitative spectroscopy reveals so much about the emitting environment. This project supports the development and application of the spectral synthesis code Cloudy. Cloudy is designed to solve these plasma, chemistry, radiation transport, and dynamics problems simultaneously and self consistently, building from a foundation of ab initio atomic and molecular cross sections and rate coefficients. It does a rigorous calculation of the atomic properties at the microscopic level. Simplistic fits to physical processes are not used. By treating the microphysics without compromise, the macrophysics, including the observed spectrum, will be correct. This makes the code suitable for application to a wide range of astronomical problems, ranging from the intracluster medium in cool-core clusters, to the innermost regions of an AGN, including the accretion disk and molecular torus. Cloudy is openly available with its documentation being cited by roughly 200 papers per year. This open access and widespread applicability ensures that the results produced by this project will see broad application. These improvements will facilitate community use of Cloudy in such diverse phenomena as starburst galaxies, gamma ray bursts, and the intergalactic medium. This project complements the Webb timeline, which currently has launch in late 2018.