AMI 15 GHz upper limits for the nearby Type Ia supernova SN 2016coj
ATel #9193; K. P. Mooley, R. P. Fender (Oxford), T. Cantwell (Manchester), D. Titterington, R. Saunders, S. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester)
on 27 Jun 2016; 19:31 UT
Credential Certification: Kunal Mooley (kunal.mooley@physics.ox.ac.uk)
Subjects: Radio, Supernovae, Transient
We observed the type Ia supernova SN 2016coj in NGC 4125 (Zheng et al., ATel #9095; d=19Mpc; discovery date 2016 May 28.18) with the AMI Large Array at 15 GHz. We detected a fading source (later found to be a chance coincidence; see below) at the location of the supernova on 2016 Jun 03.86, Jun 05.89 and Jun 09.76 UT, following which we triggered the Jansky VLA. The VLA observations, carried out between 2-18 GHz on Jun 11.07 UT, gave 3sigma upper limits of ~60 uJy at S, C, X and Ku bands. The VLA measurements together with subsequent AMI observations, which showed brightening of the source, suggest that the AMI radio source is due to some extended structure, and is not the afterglow of SN 2016coj. We can therefore place upper limits on the 15 GHz luminosity of SN 2016coj: 1e26 erg/s/Hz and 2e25 erg/s/Hz on day 6 and day 14 post-discovery respectively. The log of observations and images are posted at http://4pisky.org/atel-sn2016coj-20160627 .
We thank the AMI staff and the NRAO/VLA staff for scheduling the observations promptly.
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