Emission line spectra of Fe XI for astrophysical plasmas in the extreme ultraviolet region 60 - 140 {\AA}.

ORAL

Abstract

Accurate spectral catalogs are essential to analyze spectra of astrophysical plasmas observed by orbiting EUV and x-ray observatories, such as $Chandra,~XMM-Newton, ~Hinode$, and the $Solar ~Dynamics ~Observatory$. We report here on emission spectra of iron in the extreme ultraviolet recorded at an electron density of $\sim 5 \times 10^{11}$ cm$^{-3}$ at the Lawrence Livermore electron beam ion trap facility. In particular, we present measured spectra of Fe XI, covering the region 60 - 140 {\AA}. The spectra contain a large number of lines, which despite being rather weak compared to the stronger and better known lines above 170 {\AA}, can add up to significant flux. The measured spectra are compared to existing spectral data and newly calculated theoretical data. We use these calculations to tentatively identify the lines, most of which have not been identified before, and present measured and calculated wavelengths and line intensities. We use these measurements to identify new lines of Fe XI in the corona of Procyon, and reassign to Fe XI additional lines that had been previously attributed to other elements. We also find that the Fe XI emission contains multiple 4f -> 3d transitions that fall into one of the iron channels aboard the $SDO$ centered around 94 {\AA}.

–

Authors

  • Jaan Lepson

    Space Sciences Laboratory, University of California, Berkeley

  • Peter Beiersdorfer

    Lawrence Livermore National Laboratory

  • C. Jennings

    Stanford University, None, none, Univ of California - Merced, Dr. Remeis-Sternwarte & ECAP, Universität Erlangen-Nürnberg, NASA GSFC, Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory, Goddard Space Flight Center-NASA, University of Nevada, Reno, Cal Poly - San Luis Obispo, Victoria University of Wellington, Wellington 6021, New Zealand, Penn State, Micron School of Materials Science & Engineering, Department of Physics, Boise State University, Autonomous University of Zacatecas, Micron School of Materials Science & Engineering, Boise State University, Naval Research Laboratory, Independent Researcher, Cornell University, UC Santa Cruz, Middle Georgia State University, University of California, Merced, Stanford University, California, Institute of Medical Biology, Singapore; Stanford University, California, University of California Merced, Kent State University, ORNL, UC Berkeley, LLNL, Physics, Hokkaido University, Japan, Physics, UC San Diego, Physics, California State University, Fresno, Department of Physics and Astronomy, California State University Long Beach, Long Beach, California 90840, USA, Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA, Department of Physics, Southern University of Science and Technology, Shenzen 518055, China, Virginia Tech, Sotera Defense Solutions, Inc., Univ of California - Santa Cruz, College of Staten Island, UC Irvine, Naval Research Laboratory, Washington, DC 20375, Virginia Tech, Blacksburg, VA 24061, University of California, Merced CA 95343

  • C. Jennings

    Stanford University, None, none, Univ of California - Merced, Dr. Remeis-Sternwarte & ECAP, Universität Erlangen-Nürnberg, NASA GSFC, Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory, Goddard Space Flight Center-NASA, University of Nevada, Reno, Cal Poly - San Luis Obispo, Victoria University of Wellington, Wellington 6021, New Zealand, Penn State, Micron School of Materials Science & Engineering, Department of Physics, Boise State University, Autonomous University of Zacatecas, Micron School of Materials Science & Engineering, Boise State University, Naval Research Laboratory, Independent Researcher, Cornell University, UC Santa Cruz, Middle Georgia State University, University of California, Merced, Stanford University, California, Institute of Medical Biology, Singapore; Stanford University, California, University of California Merced, Kent State University, ORNL, UC Berkeley, LLNL, Physics, Hokkaido University, Japan, Physics, UC San Diego, Physics, California State University, Fresno, Department of Physics and Astronomy, California State University Long Beach, Long Beach, California 90840, USA, Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA, Department of Physics, Southern University of Science and Technology, Shenzen 518055, China, Virginia Tech, Sotera Defense Solutions, Inc., Univ of California - Santa Cruz, College of Staten Island, UC Irvine, Naval Research Laboratory, Washington, DC 20375, Virginia Tech, Blacksburg, VA 24061, University of California, Merced CA 95343