DCL: HBCU: Computational Atomic Laboratory Astrophysics for Stellar and Nebular Spectral Diagnostics

Clark Atlanta University, Atlanta GA

Investigators

Abstract

Atomic spectra---the unique energy signatures of atoms---carry important information about the physical conditions of the astronomical environments in which the atoms are found. The main goal of this research project is to perform accurate calculations of key properties of atoms that are found in stars and gas clouds in space. Accurate values of these properties will allow astronomers to reliably analyze atomic spectra from these distant astronomical objects and infer the conditions present there. The project will train a graduate student and a postdoctoral researcher in methods of advanced computational research, and it will increase the participation of underrepresented minority students in research. This research project will study "iron-peak" elements to better exploit them as diagnostic probes of the atmospheres of late-type stars and gaseous nebulae. The researchers will calculate accurate photoionization cross-sections, radiative and collisional rates, and electron excitation rates for the singly charged ions Fe II, Cr II, Ti II, and Sc II using innovative computational methods and numerical codes. Accurate data generated in the study will allow reliable spectral analysis of stellar and nebular regions because uncertainties in atomic data are thought to be a major source of discrepancy between the measured and calculated abundances of singly changed ions of the iron-peak elements. The new data will be incorporated into the widely used modeling code CLOUDY, and they will be made available to the astronomical community via atomic databases such as CHIANTI. The project will train a graduate student and a postdoctoral researcher in computational laboratory astrophysics techniques, and it will provide opportunities to train underrepresented minority students in advanced computational research.