SN 1987A: The Formation and Evolution of Dust in a Supernova Explosion
Abstract
From Supernova to Supernova Remnant, SN 1987A has given us a unique opportunity to study the mechanics of a supernova explosion and now to witness the birth of a supernova remnant. We want to understand how massive stars age and explode, how their ejecta form dust and molecules and how the blast wave from their violent explosion affects their surroundings.
The central stellar ejecta of SN 1987A is surrounded by a ring of progenitor gas and dust that has been shocked by the blast wave of the explosion, which is now leaving it and moving farther into the Interstellar Medium (ISM), which can thus be explored for the first time. SPITZER observations have shown that silicate dust emission from the equatorial ring accounts for most of the energy observed in the 5 - 12 µm region. However, extra emission in the short wavelength region of the spectrum (3 - 5µm) has also been observed, whose origin is still unclear: the excess may be due either to the presence of a secondary dust component (most probably of carbon type) or to free-free radiation. Our MIRI observations will help resolve this issue. ALMA has discovered a large quantity (0.4-0.7 M?) of cold dust (20 - 25K) in the ejecta. This came as a surprise for the dust discovered at day about 500 was much warmer and in a much lower quantity. Although MIRI will not be able to help in studying this very cold dust, our observations may provide clues on the fate of this warmest dust, and hence about its evolution with time, through imaging and MRS spectroscopy. Further, the ejecta is now hit by the reverse shock whose effects will be observed with IFU spectroscopy (MRS and NIRSPEC). In addition, MRS spectroscopy will study the 30µm region where SOFIA has observed an excess emission at about day 10730 which is not understood. In summary, both the MRS and NIRSpec IFU spectroscopy will measure key shocked line diagnostics that will constrain the shock physics as well as the elemental abundances in both the ring and the stellar ejecta, while imaging and IFU spectroscopy in the mid-IR will provide key information about the morphology and the Spectral Energy Distribution of both components. The environment of SN1987A has significant star formation activity, which has been studied using HST imaging during parallel HST spectroscopic observations of SN 1987A. This star formation will be studied using parallel fields when SN 1987A is the prime target.- Publication:
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JWST Proposal. Cycle 1
- Pub Date:
- July 2017
- Bibcode:
- 2017jwst.prop.1232W