EVN measurements show no evidence for radio emission from the Type Ia SN 2014J
ATel #6153; M. Perez-Torres (IAA-CSIC, Granada; CEFCA, Teruel), P. Lundqvist (Dept. of Astronomy, Stockholm University), Z. Paragi (JIVE, Dwingeloo), C. I. Bjornsson (Dept. of Astronomy, Stockholm University), C. Fransson (Dept. of Astronomy, Stockholm University), A. Alberdi (IAA-CSIC, Granada), M. K. Argo (JBCA, Manchester), R. Beswick (JBCA, Manchester), J. C. Guirado (Universidad de Valencia), J. M. Marcaide (Univ. de Valencia), I. Martí-Vidal (Onsala Space Observatory), T. W.M. Muxlow (JBCA, Manchester), E. Ros (Max-Planck Institute fuer Radioastronomie, Bonn) S. Ryder (AAO, Sydney), B. Schmidt (Mount Stromlo Observatory)
on 21 May 2014; 06:43 UT
Credential Certification: Miguel A. Perez-Torres (torres@iaa.es)
Subjects: Radio, Supernovae
Referred to by ATel #: 6197
We report deep electronic European VLBI Network (eEVN) 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 eEVN on 3 February 2014 and 19 February
2014, at a frequency of 1.66 GHz.
Our observations on both epochs included the following
EVN stations: Effelsberg, Westerbork (phased array), Jodrell
Mk 2, Medicina, Onsala, and Torun. In addition, the Noto and Shanghai
stations also took part in the 19 February observations.
The total synthesized bandwidth at the central frequency of 1.67 GHz
was of 128 MHz, for both epochs, yielding
synthesized Gaussian beams of (41 x 36) and (30 x 27) sq. milliarcsec
for the 3 and 9 February observations, respectively. We centered our
observations at the accurate SN position given by Smith et al. (ATel
#5821),
and imaged a field of view of (3 x 3) sq. arcsec around the SN,
applying standard radio interferometric procedures.
We find no evidence of radio emission above a 3-sigma limit of
32.4 and 28.5 microJy/beam at 1.66 GHz, in the
region surrounding SN 2014J. Those values correspond to upper limits
of 4.7e23 erg/s/Hz and 4.2e23 erg/s/Hz (3-sigma figures) for the
monochromatic luminosity of the supernova at 1.67 GHz, which
represent, together with those obtained for SN
2011fe, the most stringent upper limits to the radio luminosity of a Type Ia SN
ever, strongly favouring a double degenerate scenario for the
progenitor system of SN 2014J. A full discussion of those results, as
well as of those published in ATel #6149, can be found in
http://arxiv.org/abs/1405.4702.
We thank the eEVN Programme Committee and the EVN directors for supporting
those observations.
The European VLBI Network (EVN) is a joint facility of European, Chinese, South African, and
other radio astronomy institutes funded by their national research councils.
The research leading to these results has received funding from the European Commission Seventh Framework Programme (FP/2007-2013) under grant agreement No 283393 (RadioNet3).