ALMA Observations of Supernova 1987A

The explosion of Supernova (SN) 1987A was detected in the Large Magellanic Cloud, only 50 kpc away from the Solar system. This was the nearest SN explosion detected in 400 years. Due to its close distance, SN 1987A has enabled us to investigate the evolution of supernovae in unprecedented detail. With its superb sensitivity and angular resolutions at submillimeter and millimetre wavelengths, ALMA is discovering new aspects of Supernova 1987A. The ALMA high angular resolution images showed thermal emission from cold dust thermal confined in the SN ejecta, proving that SN can form nearly a solar mass of dust from its newly synthesised elements. The ALMA helps our understanding of dust formation in SNe, and further helps answering the question whether SN dust can be an important source of dust in galaxies or not. ALMA also discovered unexpectedly strong CO and SiO rotational lines in SN 1987A. These detections provide a key to understand molecular chemistry in SNe in the time scale of 20 years. Further, the ALMA covers the low frequency range of the synchrotron radiation arising from SN 1987A. The comparison of 213 and 345 GHz images taken from ALMA at with 44-108 GHz ATCA images showed that the spectral power indices of the synchrotron radiation varies within the SN. This suggests the presence of a range of strengths in shock interactions within the system.