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Title: INFRARED CONTINUUM AND LINE EVOLUTION OF THE EQUATORIAL RING AROUND SN 1987A

Spitzer observations of SN 1987A have now spanned more than a decade. Since day ∼4000, mid-infrared (mid-IR) emission has been dominated by that from shock-heated dust in the equatorial ring (ER). From 6000 to 8000 days after the explosion, Spitzer observations included broadband photometry at 3.6–24 μm, and low and moderate resolution spectroscopy at 5–35 μm. Here we present later Spitzer observations, through day 10,377, which include only the broadband measurements at 3.6 and 4.5 μm. These data show that the 3.6 and 4.5 μm brightness has clearly begun to fade after day ∼8500, and no longer tracks the X-ray emission as well as it did at earlier epochs. This can be explained by the destruction of the dust in the ER on timescales shorter than the cooling time for the shocked gas. We find that the evolution of the late time IR emission is also similar to the now fading optical emission. We provide the complete record of the IR emission lines, as seen by Spitzer prior to day 8000. The past evolution of the gas as seen by the IR emission lines seems largely consistent with the optical emission, although the IR [Fe ii] and [Si ii] linesmore » show different, peculiar velocity structures.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ; ;  [6] ;  [7]
  1. CRESST/UMBC (United States)
  2. Observational Cosmology Lab, Code 665, NASA/GSFC, Greenbelt, MD 20771 (United States)
  3. Laboratoire AIM Paris-Saclay, CEA-IRFU/SAp, CNRS, Université Paris Diderot, F-91191 Gif-sur-Yvette (France)
  4. INAF-Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, I-34143 Trieste (Italy)
  5. Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)
  6. Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, 116 Church Street, SE, Minneapolis, MN 55455 (United States)
  7. Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)
Publication Date:
OSTI Identifier:
22519996
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (Online); Journal Volume: 151; Journal Issue: 3; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION SPECTROSCOPY; BRIGHTNESS; COOLING TIME; EMISSION SPECTROSCOPY; INTERMEDIATE INFRARED RADIATION; IRON; PHOTOMETRY; RESOLUTION; SILICON; SUPERNOVAE; VELOCITY