A1 Refereed original research article in a scientific journal
SN 1978K: An evolved supernova outside our Local Group detected at millimetre wavelengths
Authors: Ryder SD, Kotak R, Smith IA, Tingay SJ, Kool EC, Polshaw J
Publisher: EDP SCIENCES S A
Publication year: 2016
Journal: Astronomy and Astrophysics
Journal name in source: ASTRONOMY & ASTROPHYSICS
Journal acronym: ASTRON ASTROPHYS
Article number: ARTN L9
Volume: 595
Number of pages: 4
ISSN: 1432-0746
DOI: https://doi.org/10.1051/0004-6361/201629763
Abstract
Supernova 1978K is one of the oldest-known examples of the class of Type IIn supernovae that show evidence for strong interaction between the blast wave and a dense, pre-existing circumstellar medium. Here we report detections of SN 1978K at both 34 GHz and 94 GHz, making it only the third extragalactic supernova (after SN 1987A and SN 1996cr) to be detected at late-times at these frequencies. We find SN 1978K to be >400 times more luminous than SN 1987A at millimetre wavelengths in spite of the roughly nine year difference in ages, highlighting the risk in adopting SN 1987A as a template for the evolution of core-collapse supernovae in general. Additionally, from new VLBI observations at 8.4 GHz, we measure a deconvolved diameter for SN 1978K of similar to 5 milli-arcsec, and a corresponding average expansion velocity of < 1500 km s(-1). These observations provide independent evidence of an extremely dense circumstellar medium surrounding the progenitor star.
Supernova 1978K is one of the oldest-known examples of the class of Type IIn supernovae that show evidence for strong interaction between the blast wave and a dense, pre-existing circumstellar medium. Here we report detections of SN 1978K at both 34 GHz and 94 GHz, making it only the third extragalactic supernova (after SN 1987A and SN 1996cr) to be detected at late-times at these frequencies. We find SN 1978K to be >400 times more luminous than SN 1987A at millimetre wavelengths in spite of the roughly nine year difference in ages, highlighting the risk in adopting SN 1987A as a template for the evolution of core-collapse supernovae in general. Additionally, from new VLBI observations at 8.4 GHz, we measure a deconvolved diameter for SN 1978K of similar to 5 milli-arcsec, and a corresponding average expansion velocity of < 1500 km s(-1). These observations provide independent evidence of an extremely dense circumstellar medium surrounding the progenitor star.
UTU Research Portal