Stancil Research Group
Our work is at the interface of atomic and molecular (AM) physics with astrophysics. Accurate and complete AM data are required to facilitate reliable interpretation and modeling of astronomical observations. With the rapid advances in space- and ground-based telescope technology, the need for accurate AM data will only become more crucial. Using state-of-the-art quantum-mechanical techniques, we compute atomic and molecular data (cross sections, rate coefficients, transition probabilities, . . .) needed for the modeling of various astronomical environments. We either work closely with other theoretical astrophysicists to utilize this data in their models or we develop our own models.
Our AM physics program includes the investigation of charge transfer due to ion-atom and ion-molecule collisions, formation of diatomic molecules by radiative association, and photodissociation of diatomic molecules. We are involved in a large project to compute a comprehensive set of total and state-selective charge transfer data for use in astrophysical modeling. This data will be made available to the scientific user community via the WWW. We are now extending our program to include formation and destruction of polyatomic molecules, molecular line lists, and rovibrational (de)excitation due to neutral particle collisions.
Our research efforts in astrophysics have been primarily focused on the early Universe. Using the most recently available AM data, some computed by our group, we have investigated the formation of atoms and molecules in the recombination era. We have just began a new project to extend this work to the formation of the very first cosmological objects, i.e., primordial stars and galaxies, with an emphasis on the role of primordial molecules. We are also interested in other astrophysical and atmospheric environments including brown dwarfs, x-ray emission for Jupiter and comets, extrasolar giant planets, supernova ejecta, stellar atmospheres, and the interstellar medium.
Distinguished Undergraduate Researchers
Undergraduate students in the Stancil Research group perform research in hot topics in AMO physics and astrophysics. These students are highly competitive and rewarded with publications and departmental awards.
We would like to congratulate four of our students who have been distinguished with departmental awards for the year of 2017.
D. R. Schultz, S. Yu Ovchinnikov, P. C. Stancil, and T. Zaman, “Elastic, charge transfer, and related transport cross sections for proton impact of atomic hydrogen for astrophysical and laboratory plasma modeling,” J. Phys. B, submitted (Nov. 13, 2015).
R. C. Forrey, J. F. Babb, P. C. Stancil, and B. M. McLaughlin, “Formation of silicon monoxide by radiative association: the impact of resonances,” J. Phys. B, submitted (Nov. 13, 2015).
E. C. McMillan, G. Shen, J. F. McCann, B. M. McLaughlin, and P. C. Stancil, “Rovibrationally-resolved photodissociation of SH+,” J. Phys. B, submitted (Nov. 8, 2015).
Gu, L., Kaastra, J., Raassen, A. J. J., Mullen, P. D., Cumbee, R. S., Lyons, D., and Stancil, P. C., 2015, A novel scenario for the possible X-ray line feature at 3.5 keV: Charge exchange with bare sulfur ions, A&A, 2015, 584, L11
G. Shen, A. Kuri, J. M. Fontenla, P. C. Stancil, and J. G. Wang, “Rovibrationally- resolved photodissociation of NH and applications to the interstellar medium and the stellar UV opacity,” Astrophys. J., submitted (Sept. 13, 2015).
Mullen, P. D., Cumbee, R. S., Lyons, D. and Stancil, P.S., Charge Exchange Induced X-Ray Emission of Fe XXV and Fe XXVI, 2015, ApJ, In Press
Cumbee, R. S., Liu, L., Lyons, D., Schultz, D. R., Stancil, P. C., Wang, J. G., and Ali, R. Ne X X-ray Emission due to Charge Exchange in M82, 2015, MNRAS, In Press
L. Song, N. Balakrishnan, K. M. Walker, P. C. Stancil, W.-F. Thi, I. Kamp, A. van der Avoird, and G. C. Groenenboom, , “Quantum Calculation of Inelastic CO Collisions with H. III. Rate Coefficients for Ro-Vibrational Transitions,” Astrophys. J. 813, 96 (2015).
K. M. Walker, B. H. Yang, P. C. Stancil, N. Balakrishnan, and R. C. Forrey, On the validity of collider-mass scaling for molecular rotational excitation, Astrophysical Journal 790, 96 (2014)
Cumbee, Renata S.; Henley, David B.; Stancil, Phillip C.; Shelton, Robin L.; Nolte, Jeff L.; Wu, Yong; Schultz, David R., Can Charge Exchange Explain Anomalous Soft X-ray Emission in the Cygnus Loop?, Astrophysical Journal Letters 787, L31 (2014).
B. Yang, P. C. Stancil, N. Balakrishnan, R. C. Forrey, J. M. Bowman, Quantum Calculation of Inelastic CO Collisions with H: I. Rotational Quenching of Low-lying Rotational Levels, Astrophysical Journal 771, 49 (2013).
K. M. Walker, L. Song, B. H. Yang, G. C. Groenenboom, A. van der Avoird, N. Balakrishnan, R. C. Forrey, and P. C. Stancil, “Quantum Calculation of Inelastic CO Collisions with H. II. Pure rotational quenching of high rotational levels,” Astrophys. J., 811, 27 (2015).