The GRB Afterglow Modeling Project: Extinction of Extragalactic Point Sources

ORAL

Abstract

The Afterglow Modeling Project (AMP) will determine, in a statistically self-consistent way, parameters that describe the time- and frequency-dependent emission and absorption of every gamma-ray burst (GRB) afterglow observed since the first detection in 1997. The result will be an ever-growing catalog of GRB afterglow models that can itself be analyzed to better describe the range of and relationships among the physical properties of GRBs and their environments. We present the model for GRB afterglow extinction. Approximately 40 parameters describe line-of-sight extinction due to: dust, neutral Hydrogen and molecular Hydrogen in the GRB host galaxy; neutral Hydrogen in the intergalactic medium (the Lyman-alpha forest); and dust in our own Galaxy. This very large parameter space is significantly reduced by priors, which we determined by analyzing previously published extinction measurements of stars in our Galaxy, and flux deficits due to Lyman-alpha absorption in the spectra of quasars at redshifts in the range 1$<$ z$<$5 (which includes the Gunn-Peterson trough). The AMP project aside, these parameters and priors can be used to model extinction towards any extragalactic point source, including supernovae.

Authors

  • Adam Trotter

    University of North Carolina, Chapel Hill

  • Jaetae Seo

    NC A\&T State University, Penn State University, The Ohio State University, Wright State University, AFRL/RYHC Hanscom AFB MA 01731, Harvard University, The College of William \& Mary, NCSU Near-field Optics Lab, University of North Carolina at Chapel Hill, Weizmann, PTB, Braunschweig, UMass, TUNL/Duke, UConn, UConn/TUNL, University of North Carolina, Chapel Hill, North Carolina State University, Brimrose Corporation of America, Hampton University, Elizabeth City State University, Department of Physics, Florida A\&M University, Tallahassee, Florida-32307, Department of Physics, University of Rajshahi, Rajshahi-6205, Bangladesh, Department of Physics, University of Rajshahi, Rajshah-6205, Bangladesh, Department of Physics, University of Rajshahi, Rajshahi-6250, Bangladesh, Department of Physics, University of Rajshahi-6205, Bangladesh, Alabama A\&M University, Fachbereich C-Mathematik und Naturwissen-Schaften, Bergische Universitat Wuppertal, D-42097, Wuppertal, Germany, NC State University, College of William and Mary, Department of Physics, N.C. State Univeristy, Research Triangle Institute, NCSU Physics, Pennsylvania State University, Tsinghua University, Lawrence Berkeley National Laboratory, Vanderbilt University, LSU, UNIRIB, U. Tenn., ORNL, Miss. St., University of North Carolina at Chapel Hill and Triangle Universities Nuclear Laboratory, NCA\&T, Duke, NCCU, UNC-Chapel Hill, Department of Physics, North Carolina State University, Department of Chemistry, North Carolina State University, Department of Physics and Astronomy, University of North Carolina, Chapel Hill, Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hil, North Carolina School of Science and Mathematics, Department of Physics, Elon University, Dept. of Physics - UNC - Chapel Hill, Nanyang Technological University, School of Materials Sciences and Engineering, Singapore, Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3255, USA, Argonne National Laboratory, Department of Physics, Hampton University, Hampton, VA 23668, Korea Research Institute of Standards and Science, Daejeon, 305-600, South Korea, Department of Chemistry, Gyeongsang National University, Jinju 660-701, South Korea, Electronics and Telecommunications Research Institute, Daejeon, 305-700, South Korea, Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609