A very stringent upper limit to the mass-loss rate of the Type Ia SN2021J from e-MERLIN radio observations
ATel #14325; M. Perez-Torres (IAA-CSIC, Granada), J. Moldon (IAA-CSIC, Granada; JBCA, Manchester), P. Lundqvist (Stockholm University), J. Bray (JBCA), D. Venkattu (Stockholm)
on 18 Jan 2021; 06:38 UT
Credential Certification: Miguel A. Perez-Torres (torres@iaa.es)
Subjects: Radio, Supernovae
We report the non-detection at radio wavelengths of the Type Ia SN 2021J
discovered on 2021-01-01 11:44:04 at the position RA = 12:26:27.031 DEC =
+31:13:20.59 in NGC 4414 (2021TNSTR...1...1E), at a distance of 16.6 Mpc
(Kanbur et al. 2003, A&A, 411, 361), and classified as a Type Ia SN on UT
2021-01-04 (ATel #14300).
We observed SN 2021J on 2021-01-05 (from 22:45 UT till 07:40 on 2021-01-06)
and 2021-01-08 (from 03:25 till 12:30 UT) with the electronic Multi-Element
Radio Linked Interferometer Network (e-MERLIN) at a central frequency of 5.1
GHz, and with a bandwidth of 512 MHz. We found no evidence of radio emission
from SN 2021J in either epoch above a 3-sigma upper limit of 45 and 60
microJy/beam, respectively, which correspond to upper limits of the
monochromatic luminosity of 1.5E25 and 2.0E25 erg/s. Assuming that the
first epoch happened 4.0 days after the explosion, the upper limits to the
luminosity of SN 2021J correspond to 3-sigma upper limits to the mass-loss rate
of the progenitor star of 7.8E-9 and 1.6E-8 solar masses per year at 4.0 days
and 7.3 days after the SN explosion, for a presupernova wind of 100 km/s, using
the same model as for previous Type Ia SNe (e.g., ATel #12411 for SN 2019np).
The value of 7.8E-9 Msol/yr is one of the most stringent upper limits ever, only
beaten by those obtained for SN 2011fe, SN 2012cg and SN 2014J, and at the same
level as those for SN 2011by, SN 2011ek, SN 2012fr and SN 2012ht.
e-MERLIN is a National Facility operated by the University of Manchester at
Jodrell Bank Observatory on behalf of STFC.
