Infrared Continuum and Line Evolution of the Equatorial Ring around SN 1987A

Abstract

Spitzer observations of SN 1987A have now spanned more than a decade. Since day ~4,000, mid-infrared (mid-IR) emission has been dominated by that from shock-heated dust in the equatorial ring (ER). From 6,000 to 8,000 days after the explosion, Spitzer observations included broadband photometry at 3.6 - 24 micron, and low and moderate resolution spectroscopy at 5 - 35 micron. Here we present later Spitzer observations, through day 10,377, which include only the broadband measurements at 3.6 and 4.5 micron. These data show that the 3.6 and 4.5 micron brightness has clearly begun to fade after day ~8,500, 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 time scales 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 8,000. 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] lines show different, peculiar velocity structures.

Accepted for publication in AJ. 22 pages, 18 figures

References in corpus (15)

• Early Science with SOFIA, the Stratospheric Observatory for Infrared Astronomy
• A stubbornly large mass of cold dust in the ejecta of Supernova 1987A
• Spitzer Space Telescope Infrared Imaging and Spectroscopy of the Crab Nebula
• Discovery of a nearby twin of SN1987A's nebula around the luminous blue variable HD168625: Was Sk--69 202 an LBV?
• Spitzer spectral line mapping of supernova remnants: I. Basic data and principal component analysis
• The Destruction of the Circumstellar Ring of SN 1987A
• Infrared and X-Ray Evidence for Circumstellar Grain Destruction by the Blast Wave of Supernova 1987A
• The Evolution of Dust Mass in the Ejecta of SN1987A
• Spectral and morphological analysis of the remnant of Supernova 1987A with ALMA & ATCA
• Time evolution of the line emission from the inner circumstellar ring of SN 1987A and its hot spots
• Evolutionary Status of SNR 1987A at the Age of Eighteen
• Evidence of the Evolved Nature of the B[e] Star MWC 137
• The blue supergiant MN18 and its bipolar circumstellar nebula
• Spitzer IRS Observations of the XA Region in the Cygnus Loop Supernova Remnant
• Mapping High-velocity H-alpha and Lyman-alpha Emission from Supernova 1987A

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