The evolution of Radio supernova SN2008iz in M82 Galaxy
Abstract
Radio-loud supernovae are rare events with just a few dozen detected. The majority of them are relatively distant or fairly weak, making them difficult to study in great detail. To date, the best known example is SN1993J in M81 galaxy which has been studied extensively due to its proximity (3.63Mpc), environment (which allows for multi-wavelength studies) and galaxy orientation (M81 is almost face-on). The discovery of SN2008iz in M82 galaxy offers the possibility to study another supernova at a very similar distance in great detail and to make a comparison to SN1993J. We report on multi-frequency VLA and VLBI radio observations for a monitoring campaign of supernova SN2008iz. The late-time radio light curve evolution shows flux-density flares at between 970 and 1400 days, which does not show signs of decline at least from results examined. The derived spectral index also shows no signs of evolution and remains steep ~-1 throughout the period, unlike that of SN1993J which started flattening at day 970. From the 4.8 and 8.4GHz VLBI images, the supernova expansion is seen to start with shell like structure that gets more and more asymmetric, then breaks up in the later epochs with bright structures dominating the southern part of the ring, with an average expansion velocity between days 73 and 1400 of 12000km/s.
- Publication:
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AFAS2 2021: Conference of the African Astronomical Society
- Pub Date:
- March 2021
- Bibcode:
- 2021afas.confE...8K