THE MORPHOLOGY OF THE EJECTA IN SUPERNOVA 1987A: A STUDY OVER TIME AND WAVELENGTH

• Published in: The Astrophysical journal Vol. 768; no. 1; pp. 89 - 17
• Main Authors: Larsson, Josefin, Fransson, Claes, Kjaer, Karina, Jerkstrand, Anders, Kirshner, Robert P., Leibundgut, Bruno, Lundqvist, Peter, Mattila, Seppo, McCray, Richard, Sollerman, Jesper, Spyromilio, Jason, Wheeler, J. Craig
• Format: Journal Article
• Language: English
• Published: United States 01.05.2013
• Subjects: ABSORPTION; ABUNDANCE; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Asymmetry; Ejecta; EMISSION; ENERGY SOURCES; Integral field spectroscopy; INTERACTIONS; MORPHOLOGY; NORTH-SOUTH ASYMMETRY; NUCLEAR DECAY; PROBES; Progenitors (astrophysics); RADIOACTIVITY; SPECTRA; SPECTROSCOPY; Supernova 1987A; SUPERNOVAE; supernovae: individual (SN 1987A); X RADIATION
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.1088/0004-637X/768/1/89

We present a study of the morphology of the ejecta in Supernova 1987A based on images and spectra from the Hubble Space Telescope (HST) as well as integral field spectroscopy from VLT/SINFONI. The HST observations were obtained between 1994 and 2011 and primarily probe the outer H-rich zones of the ejecta. The SINFONI observations were obtained in 2005 and 2011 and instead probe the [SiI]+[FeII] emission from the inner regions. We find a strong temporal evolution of the morphology in the HST images, from a roughly elliptical shape before ~5000 days, to a more irregular, edge-brightened morphology with a "hole" in the middle thereafter. Both the H alpha and the [SiI]+[FeII] line profiles show that the ejecta are distributed fairly close to the plane of the inner circumstellar ring, which is assumed to define the rotational axis of the progenitor star. We compare our results with explosion models and find some qualitative agreement, but note that the observations show a higher degree of large-scale asymmetry.