Computational Atomic and Molecular Physics and Computational Astrophysics
All of the information we receive about the universe comes to us in the form of photons (except for a handful of neutrinos). These photons are emitted by atoms and molecules which reside in the various astronomical environments. The character of this emission (e.g., the intensity) is related to the environmental parameters (e.g., density, temperature, radiation field, distribution of atoms, molecules, and electrons, etc.) that the emitting species finds itself. Therefore, there is a fundamental connection between astronomy and atomic and molecular physics.
In my research group, we are engaged in two main efforts: 1) the calculation of various atomic and molecular parameters, using modern computational techniques, which are relevant to astrophysics and 2) modeling of astrophysical environments using the results obtained in 1). Our interests include many types of astronomical objects and environments including the early Universe, the formation of the first stars, x-ray emission from comets and planets, extrasolar giant planets, cool stellar atmospheres, supernovae, and planetary nebulae.
Students working in my research group will receive hands-on exposure to atomic and molecular physics, computational physics and numerical methods, and theoretical molecular astrophysics. For students taking the PHYS 8990 course, I offer two original projects:
- Rotational excitation and deexcitation of HD due to He collisions. The student will calculate the cross sections and rate coefficients for this process using a public-domain computer code. Calculations will be done for quenching of J=1 to J=0 from the ultracold (10-4 K) to astrophysically-relevant temperatures (500 K). HD is observed in a variety of astronomical objects and excitation rate coefficients are used to calculate the strength of the observed rotational lines. It is also of interest to study the process at ultracold temperatures due to current laboratory efforts to produce cold molecules (less than 1 K). If time permits, the role of HD in cooling low-density gas will be explored and its relative importance compared to H2. Some experience with Unix and Fortran, or C++, would be helpful, but is not a requirement.