Spectroscopic Study of Nuclear Processing in the Crab Nebula

POSTER

Abstract

We present correlations for optical and near-infrared line intensity measurements at many positions in the Crab Nebula supernova remnant. These correlations suggest the existence of gas produced by a range of nuclear processing, from material in which synthesis ended with the CNO-cycle, to some helium-burning and nitrogen depletion, to regions containing enriched products of oxygen-burning. The latter exhibit a gradual, linear rise of [Ni II] emission with increasing argon enrichment, whereas gas with less nuclear processing shows markedly different [Ni II] emission characteristics, including the highest derived abundances. This suggests two origins for stable, neutron-rich nickel in the nebula: a type of ``alpha-rich freezeout'' in the most highly processed material, and perhaps removal of ions from the neutron star in other regions. In addition, the data indicate that anomalously strong observed [C I] emission comes from extensive, warm, low-ionization zones. Although the strongest He I emission could also be enhanced in similar low-ionization gas, correlations between relevant line ratios argue against that explanation, strengthening the case for an exceptionally high helium mass fraction in some locations.

Authors

  • Gordon MacAlpine

  • Dana Dunn

    University of Texas at Arlington, Peoples Friendship University of the Russia, TSAAPT Officer, University of Texas at El Paso, Department of Chemistry, Stephen F. Austin University, Department of Physics, Stephen F. Austin University, Highland Park High School, Dallas, Texas, Lamar High School, Arlington, Texas, Angelo State University, Abilene Christian University, Southern Nazarene University, Texas Tech University, Sam Houston State University, University of Texas at Austin, Cornell University, University of Houston, University of Texas Center for Relativity, Ion Beam Modification and Analysis Laboratory (IBMAL), University of North Texas, University of North Texas, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083, Department of Physics, The University of Texas at Arlington, Arlington, Texas 76019, Department of Physics, University of Texas at Arlington, Arlington, TX, 76019, UTA High Energy Physics Group, Univ. of Texas, Arlington, USA, KAERI Korea, Changwon National Univ., Korea, Rutgers University, Iowa State University, Rigaku/MSC, Texas Christian University, Dept. of Physics, Changwon National University, Department of Physics, University of North Texas, Department of Chemistry and Biochemistry, Arizona State University, Research Center, Philip Morris USA, Harrington Department Bioengineering Arizona State University, Universidad Autonoma de Colima, Universidad de Buenos Aires, Department of Physics, University of Texas, Arlington, Chair, Department of Physics, University of Texas at Arlington, Dean of Science, University of Texas at Arlington, President, University of Texas at Arlington, Department of Electrical Engineering, Princeton University, Department of Physics, Texas A\&M University, NanoFAB Center and Electrical Engineering Department, University of Texas at Arlington, University of Texas at San Antonio, SEMATECH, University of Texas at Dallas, CINVESTAV Queretaro, Mexico and University of Texas at Dallas, Texas A\&M University, Departamento de F\'isica, FCEN, Universidad de Buenos Aires, Freescale Semiconductor, Inc., Department of Physics, UT Austin, Physics Department, The University of Texas at Arlington, Department of Physics, University of Texas at Arlington, Tolar High School, Granbury High School

  • Dana Dunn

    University of Texas at Arlington, Peoples Friendship University of the Russia, TSAAPT Officer, University of Texas at El Paso, Department of Chemistry, Stephen F. Austin University, Department of Physics, Stephen F. Austin University, Highland Park High School, Dallas, Texas, Lamar High School, Arlington, Texas, Angelo State University, Abilene Christian University, Southern Nazarene University, Texas Tech University, Sam Houston State University, University of Texas at Austin, Cornell University, University of Houston, University of Texas Center for Relativity, Ion Beam Modification and Analysis Laboratory (IBMAL), University of North Texas, University of North Texas, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083, Department of Physics, The University of Texas at Arlington, Arlington, Texas 76019, Department of Physics, University of Texas at Arlington, Arlington, TX, 76019, UTA High Energy Physics Group, Univ. of Texas, Arlington, USA, KAERI Korea, Changwon National Univ., Korea, Rutgers University, Iowa State University, Rigaku/MSC, Texas Christian University, Dept. of Physics, Changwon National University, Department of Physics, University of North Texas, Department of Chemistry and Biochemistry, Arizona State University, Research Center, Philip Morris USA, Harrington Department Bioengineering Arizona State University, Universidad Autonoma de Colima, Universidad de Buenos Aires, Department of Physics, University of Texas, Arlington, Chair, Department of Physics, University of Texas at Arlington, Dean of Science, University of Texas at Arlington, President, University of Texas at Arlington, Department of Electrical Engineering, Princeton University, Department of Physics, Texas A\&M University, NanoFAB Center and Electrical Engineering Department, University of Texas at Arlington, University of Texas at San Antonio, SEMATECH, University of Texas at Dallas, CINVESTAV Queretaro, Mexico and University of Texas at Dallas, Texas A\&M University, Departamento de F\'isica, FCEN, Universidad de Buenos Aires, Freescale Semiconductor, Inc., Department of Physics, UT Austin, Physics Department, The University of Texas at Arlington, Department of Physics, University of Texas at Arlington, Tolar High School, Granbury High School

  • Steven Vanderveer

    Trinity University