SN 2014bc, SN2014bi and SN 1981K not detected in radio
ATel #6429; Michael Bietenholz (York University, Canada and HartRAO, South Africa) and Norbert Bartel (York University, Canada)
on 29 Aug 2014; 20:52 UT
Credential Certification: Michael Bietenholz (mbieten@yorku.ca)
Subjects: Radio, Supernovae
We report on 10 GHz Jansky Very Large Array radio observations of SN 2014bc (Psn J12185771+4718113; Smartt et al CBET #3877) and SN 2014bi (PSN J12060299+4729335; Kumar et al, CBET #3892), as well as SN 1981K. The observations were on 2014 Aug 07.0 (UTC) spanned a bandwidth from 8 to 12 GHz, and were made with the array in the D-configuration (resolution ~5"). None of the three supernovae is detected.
SN 2014bc, in NGC 4258 (M106) is a Type IIP supernova in the galaxy NGC 4258, only 3.1" away from the galaxy nucleus. In our radio image, the supernova is not distinguishable from the radio-bright nucleus. We place an upper limit of 2 mJy on the 10-GHz flux density of the supernova, corresponding to spectral luminosity of 1.4 x 10^26 erg/s/Hz (for a distance of 7.6 Mpc)
SN 1981K, also in NGC 4258 was also not detected. We place a 3-sigma upper limit of 74 micro-Jy on its 10-GHz flux density. This value corresponds to a spectral luminosity of 5.1 x 10^24 erg/s/Hz, consistent with an extrapolation of the decay observed in van Dyk et al, 1992, ApJ, v396, p195.
SN 2014bi in the galaxy NGC 4096, is a low-luminosity Type IIP supernova. We place a 3-sigma upper limit of 96 uJy on its 10-GHz flux density, corresponding to a spectral luminosity of 7.2 x 10^24 erg/s/Hz (for a distance of 7.9 Mpc)
