Upper limits to the radio emission of the Type Ia SN 2014J from eMERLIN observations
ATel #6149; R. Beswick (JBCA, Manchester), T. W.M. Muxlow (JBCA, Manchester), M. Perez-Torres (IAA-CSIC, Granada; CEFCA, Teruel), P. Lundqvist (Dept. of Astronomy, Stockholm University), M. K. Argo (JBCA, Manchester), C. I. Bjornsson (Dept. of Astronomy, Stockholm University), C. Fransson (Dept. of Astronomy, Stockholm University), S. Ryder (AAO, Sydney), B. Schmidt (Mount Stromlo Observatory), G. Anderson (Oxford University), R. Fender (Oxford University).
on 20 May 2014; 10:55 UT
Credential Certification: Miguel A. Perez-Torres (torres@iaa.es)
We report electronic Multi Element Radio
Interferometric Network (eMERLIN) radio observations of the Type Ia SN 2014J, which was
discovered on 21.8 January 2014, about 6.8 days after its explosion
(see http://www.k-itagaki.jp/psn-m82.jpg)
in the nearby (D=3.5 Mpc) galaxy NGC 3034 = M82 (cf. CBET #3792). We
observed SN 2014J with the eMERLIN on 28 January 2014, at a frequency
of 1.55 GHz, and on 29, 30 January 2014, and 2 February 2014, at a
frequency of 6.17 GHz. The radio telescopes that participated in the
observations included all eMERLIN antennas (Lovell, Jodrell Mk2,
Cambridge, Pickmere, Darnhall, Knockin, and Defford). The bandwidths
were of 512 and 1024 MHz at the central frequencies of 1.55 and 6.17
GHz, respectively, which resulted in synthesized Gaussian beams of
(0.16 x 0.14) and (0.055 x 0.031) sq. arcseconds. We centered our
observations at the position given by Smith et al. (ATel #5821)
(RA(J2000.0)=09:55:42.121 and DEC(J2000.0)=+69:40:25.88, and imaged a
field of about (15 x 15) sq. arcsec around that position.
We find no evidence of radio emission above a 3-sigma limit of
37.2 and 40.8 microJy/beam at 1.55 and 6.17 GHz, respectively, in the
region surrounding SN 2014J. Those values correspond to upper limits
of 5.5e23 erg/s/Hz and 6.0e23 erg/s/Hz (3-sigma figures) for the
monochromatic luminosity of the supernova at 1.55 and 6.17 GHz,
respectively, which represent one of the most stringent radio luminosity limits
for a Type Ia SN, and puts into serious trouble single-degnerate scenarios as
progenitor system of SN 2014J.
We thank the eMERLIN Programme Committee for supporting our ToO program in
search for radio emission from Type Ia supernovae, aimed at unveiling
their progenitor scenarios.
