1. Ejecta, Rings, and Dust in SN 1987A with JWST MIRI/MRS
- Author
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Jones, O. C., Kavanagh, P. J., Barlow, M. J., Temim, T., Fransson, C., Larsson, J., Blommaert, J. A. D. L., Meixner, M., Lau, R. M., Sargent, B., Bouchet, P., Hjorth, J., Wright, G. S., Coulais, A., Fox, O. D., Gastaud, R., Glasse, A., Habel, N., Hirschauer, A. S., Jaspers, J., Krause, O., Lenkić, Nayak, O., Rest, A., Tikkanen, T., Wesson, R., Colina, L., van Dishoeck, E. F., Güdel, M., Henning, Th., Lagage, P. -O., Östlin, Ray, T. P., and Vandenbussche, B.
- Subjects
Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Astrophysics of Galaxies ,Astrophysics - Solar and Stellar Astrophysics - Abstract
Supernova (SN) 1987A is the nearest supernova in $\sim$400 years. Using the {\em JWST} MIRI Medium Resolution Spectrograph, we spatially resolved the ejecta, equatorial ring (ER) and outer rings in the mid-infrared 12,927 days after the explosion. The spectra are rich in line and dust continuum emission, both in the ejecta and the ring. Broad emission lines (280-380~km~s$^{-1}$ FWHM) seen from all singly-ionized species originate from the expanding ER, with properties consistent with dense post-shock cooling gas. Narrower emission lines (100-170~km~s$^{-1}$ FWHM) are seen from species originating from a more extended lower-density component whose high ionization may have been produced by shocks progressing through the ER, or by the UV radiation pulse associated with the original supernova event. The asymmetric east-west dust emission in the ER has continued to fade, with constant temperature, signifying a reduction in dust mass. Small grains in the ER are preferentially destroyed, with larger grains from the progenitor surviving the transition from SN into SNR. The ER is fit with a single set of optical constants, eliminating the need for a secondary featureless hot dust component. We find several broad ejecta emission lines from [Ne~{\sc ii}], [Ar~{\sc ii}], [Fe~{\sc ii}], and [Ni~{\sc ii}]. With the exception of [Fe~{\sc ii}]~25.99$\mu$m, these all originate from the ejecta close to the ring and are likely being excited by X-rays from the interaction. The [Fe~{\sc ii}]~5.34$\mu$m to 25.99$\mu$m line ratio indicates a temperature of only a few hundred K in the inner core, consistent with being powered by ${}^{44}$Ti decay., Comment: 27 pages, 16 figures, 4 tables. Accepted ApJ
- Published
- 2023