Current models for the creation of structure in the early Universe indicate that during the epoch of first star formation, the hydrogen and deuterated hydrogen molecules are the dominant coolants for collapsing primordial gas clouds at temperatures between ten thousand and one hundred Kelvin. The recent detection of reionization, and thus star formation, at high redshift, underscores the pivotal role played by the creation and destruction of these molecules at early times. However, significant uncertainties, even to orders of magnitude, exist in the published atomic data for the particularly important charge exchange and rearrangement reactions. These uncertainties translate into major inaccuracies in the predicted relative abundances of both molecules at this key epoch. This study comprises a series of laboratory investigations to measure the rate coefficients for the relevant reactions in the relevant temperature range for cosmological object formation. New atomic data from a cylindrical radio-frequency ion trap will guide theoretical calculations, and will be introduced into models of pregalactic structure and first star formation to investigate the astrophysical implications.
This study will significantly enhance the undergraduate learning experience at the Appalachian State University, whose student body includes a high proportion from under-represented groups. The new apparatus and projects using it will greatly benefit the on-campus physics research opportunities for a diverse group of undergraduate majors and masters level students. This research will also enhance recently established collaborations amongst a number of universities and government laboratories.
