Geoffrey ClaytonGeoffrey Clayton

Ball Family Distinguished Professor

Ph.D., 1983 - University of Toronto

Louisiana State University
Department of Physics & Astronomy
233-A Nicholson Hall, Tower Dr.
Baton Rouge, LA 70803-4001
Personal Home Page

Research Interests

Astronomy - Astrophysics

My research involves the study of dust in various astrophysical environments: circumstellar, interstellar and extragalactic. I am studying how dust grain properties change from quiescent cloud to star-forming cloud to circumstellar environments.With my collaborators, I am modeling dust on microscopic and macroscopic scales to determine the role of dust in the energy budget of these various environments. We use extinction, polarization, abundance and spectroscopic observations from the UV to the IR for the same sightlines obtained from Hubble and Spitzer Space Telescopes as well as other space- and ground-based telescopes. The goal is to produce a unified model of dust which will satisfy observational constraints from all wavelengths (UV to IR) in these different environments using the DDA and MEM codes. To this end we are investigating Radiative Transfer in circumstellar, star formation and extragalactic environments. The capabilities of our Monte Carlo codes include, scattering, radiative equilibrium solutions, emission from PAHs, and scattering from aligned grains. These codes produce spectra, images, and polarization (images and spectra) for comparison with observations.

Current and Select Publications

  • Clayton, G. C., Gordon, K.D., Bianchi, L. C., Massa, D. L., Fitzpatrick, E.L., Bohlin, R.C., and Wolff, M. J., "New Ultraviolet Extinction Curves for Investellar Dust in M31*," Ap. J. 815, 1 (2015).
  • Welch, D.L., Clayton, G.C., Campbell, A., Barlow, M.J., Sugerman, B.E.K., Meixner, M., and Bank, S.H.R., "An Extremely Bright Echo Associated with Sn 2002hh," in press (November 1) (2007).
  • Clayton, G.C., Geballe, T.R., Herwig, F., Fryer, C., and Asplund, "Very large Excesses of 18O in Hydrogen-deficient Carbon and R Coronae Borealis Stars: Evidence for White Dwarf Mergers," Ap. J. 662, 1220 (2007).
  • Clayton, G.C., Kerber, F., Pirzkal, N., De Marco, O., Crowther, P.A., and Fedrow, J.M., "V605 Aql: The Older Twin of Sakurai's Object," Ap. J. Letters 646, L69 (2006).
  • Sugerman, B.E.K., Ercolano, B., Barlow, M.J., Tielens, A.G.G.M., Clayton, G.C., Zijlstra, A.A., Meixner, J. Speck, A., Gledhill, T.M., Panagia, N., Cohen, M., Gordon, K.D., Meyer, M., Fabbri, J., Welch, D.L., Regan, M.W., and Kennicutt, Jr., R.C., "Massive-Star Supernovae as Major Dust Factories in the Early Universe," Science 313, 196 (2006).
  • G.C. Clayton, K.D. Gordon, F. Salama, L.J. Allamandola, P.G. Martin, T.P. Snow, D.C.B. Whittet, A.N. Witt, and M.J. Wolff, "The Role of Polycyclic Aromatic Hydrocarbons in Ultraviolet Extinction I Probing Small Molecular PAHs," Ap. J. 592, 947 (2003).
  • Clayton, G.C., "The R Coronae Borealis Stars," PASP 108, 225 (1998).
  • J.A. Cardelli, G.C. Clayton, and J.S. Mathis, "The Relationship Between Infrared, Optical, and Ultraviolet Extinction," Ap. J. 345, 245 (1989).