• DOI:10.1093/mnras/stx830
• Corpus ID: 693014

ALMA spectral survey of Supernova 1987A – molecular inventory, chemistry, dynamics and explosive nucleosynthesis

@article{Matsuura2017ALMASS,
  title={ALMA spectral survey of Supernova 1987A – molecular inventory, chemistry, dynamics and explosive nucleosynthesis},
  author={Mikako Matsuura and R{\'e}my Indebetouw and S. E. Woosley and Valent{\'i}n Bujarrabal and F J Abell{\'a}n and Richard McCray and Julia Kamenetzky and Claes Fransson and Michael J. Barlow and Haley L. Gomez and Phil J. Cigan and I. De Looze and Jason Spyromilio and Lister Staveley-Smith and Giovanna Zanardo and Patrick F. Roche and J{\"o}rgen Larsson and Serena Viti and Jacco Th. van Loon and J. Craig Wheeler and Maarten Baes and Roger A. Chevalier and Peter Lundqvist and J. M. Marcaide and Eli Dwek and Margaret Meixner and C-Y. Ng and George Sonneborn and Jagiellonian University and UK. and University College London and University of Virginia and Usa and National Radio Astronomy Observatory and University of Southern California and Santa Cruz and Observatorio Astron'omico Nacional and Spain. and Universidad de Valencia and Berkeley and Westminster College and Salt lake City and Stockholm University and Sweden. and European Southern Observatory and Garching and H Germany and The University of Western Australia and Australia. and Arc Centre of Excellence for All-sky Astrophysics and University of Oxford and Oskar Klein Centre and Albanova and Keele University and University of North Texas and Austin and Universiteit Gent and Belgium and Nasa Goddard Space Flight Center and Space Telescope Science Institute and Johns Hopkins University and University of Hong Kong and Hong Kong and China.},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2017},
  volume={469},
  pages={3347-3362}
}

• M. Matsuura, R. Indebetouw, +61 authors China.
• Published 7 April 2017
• Physics
• Monthly Notices of the Royal Astronomical Society

We report the first molecular line survey of Supernova 1987A in the millimetre wavelength range. In the ALMA 210--300 and 340--360 GHz spectra, we detected cold (20--170 K) CO, 28SiO, HCO+ and SO, with weaker lines of 29SiO from ejecta. This is the first identification of HCO+ and SO in a young supernova remnant. We find a dip in the J=6--5 and 5--4 SiO line profiles, suggesting that the ejecta morphology is likely elongated. The difference of the CO and SiO line profiles is consistent with hydrodynamic simulations, which show that Rayleigh-Taylor instabilities cause mixing of gas, with heavier elements much more disturbed, making more elongated structure. We obtained isotopologue ratios of 28SiO/29SiO>13, 28SiO/30SiO>14, and 12CO/13CO>21, with the most likely limits of 28SiO/29SiO>128, 28SiO/30SiO>189. Low 29Si and 30Si abundances in SN 1987A are consistent with nucleosynthesis models that show inefficient formation of neutron-rich isotopes in a low metallicity environment, such as the Large Magellanic Cloud. The deduced large mass of HCO+ (~5x10^-6 Msun) and small SiS mass (<6x10^-5 Msun) might be explained by some mixing of elements immediately after the explosion. The mixing might have caused some hydrogen from the envelope to sink into carbon and oxygen-rich zones after the explosion, enabling the formation of a substantial mass of HCO+. Oxygen atoms may have penetrated into silicon and sulphur zones, suppressing formation of SiS. Our ALMA observations open up a new window to investigate chemistry, dynamics and explosive-nucleosynthesis in supernovae.