The Continuing Radio Evolution of Sn 1970g
نویسندگان
چکیده
Using the Very Large Array, we have detected radio emission from the site of SN 1970G in the Sc galaxy M101. These observations are 31 years after the supernova event, making SN 1970G the longest monitored radio supernova. With flux densities of 0.12± 0.020 mJy at 6 cm and 0.16± 0.015 mJy at 20 cm, the spectral index of −0.24 ± 0.20 appears to have flattened somewhat when compared with the previously reported value of −0.56±0.11, taken in 1990. The radio emission at 20 cm has decayed since the 1990 observations with a power-law index of β20cm = −0.28±0.13. We discuss the radio properties of this source and compare them to those of other Type II radio supernovae. Subject headings: galaxies: individual (M 101) — galaxies: general — stars: supernovae — stars: supernovae: individual (SN 1970G) — radio continuum: stars
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