Low radio frequency observation of Nova Delphini 2013
ATel #5376; Nirupam Roy (MPIfR), Nimisha G. Kantharia (NCRA-TIFR), Prasun Dutta (NCRA-TIFR), G. C. Anupama (IIA), N. M. Ashok (PRL), Dipankar P. K. Banerjee (PRL)
on 8 Sep 2013; 12:01 UT
Credential Certification: Nirupam Roy (roy.nirupam@gmail.com)
Nova Delphini 2013 (ATel #5279), a very fast (ATel #5297), optically bright
FeII type classical nova on a CO white dwarf (ATel #5282, #5304, #5337), was
observed with the Giant Metrewave Radio Telescope (GMRT) on August 28, 2013
(~2 weeks after the outburst). No radio continuum counterpart is detected at
the position of the nova down to the 3sigma flux density limit of 150 microJy
at 1.3 GHz. Earlier observations with the VLA and the CARMA also detected no
radio emission at 5 - 96 GHz (ATel #5298), constraining the distance to be
more than 2 kpc. Interestingly, gamma rays are detected from this nova by the
Fermi Large Area Telescope (LAT), whereas no X-ray emission is detected so far
(ATel #5283, #5305, #5318).
Assuming the presence of a relativistic population of particles in the system
since gamma rays have been detected, we use equipartition of energy to estimate
the minimum magnetic field from our limit at 1.3 GHz. We constrain the
magnetic field to be less than 3.9 G assuming that the distance to the nova is
3.5 kpc (ATel #5297) and the emitting region is 0.1 AU. Alternatively the
radio synchrotron emission maybe heavily absorbed. Further multiwavelength
monitoring of this interesting source is highly encouraged.
We thank the staff of the GMRT who made these observations possible. The GMRT
is operated by the National Centre for Radio Astrophysics of the Tata
Institute of Fundamental Research (NCRA-TIFR).