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GCN Circular 7178

Discovery of Radio Emission from Transient in NGC 2770
2008-01-13T16:05:36Z (16 years ago)
Alicia Soderberg at Caltech <>
A. Soderberg (Princeton) reports on behalf of a large collaboration:

"We observed the field of the NGC 2770 X-ray transient (Berger & 
Soderberg, GCN 7159) on Jan 13.3 UT with the Very Large Array.  Based on a 
comparison with our pre-explosion radio data (Soderberg, ATEL 1350) 
we report the discovery of a new radio source at position (J2000):

RA = 09:09:30.6506 +- 0.0008
Dec = +33:08:20.14 +- 0.01

which is consistent with the positions of the optical (Deng & Shu, GCN 
7160), UVOT (Kong et al. ATEL 1356; Immler et al. GCN 7168), and X-ray 
(Page et al. GCN 7170) counterparts.  We note that these radio data
provide the most accurate position for the transient and its associated 
Type Ibc supernova, SN 2008D (Malesani et al. GCN 7169).

The flux density of the unresolved source is 0.12 +- 0.02 mJy at 8.46 GHz.
At a distance of 27 Mpc, this measurement corresponds to a radio spectral 
luminosity of 10^26 erg/s/Hz, comparable to that of Type Ibc SNe 
2002ap (Berger, Kulkarni & Chevlier, ApJL, 2002) and 2007gr (Soderberg,
ATEL 1187) and a factor of 100 lower than that of sub-energetic GRBs 
980425 (Kulkarni et al. Nature, 1998) and 060218 (Soderberg et al.
Nature, 2006) at comparable epochs.

Radio observations are ongoing.

We thank the VLA scheduling officers for their continued support in this
monitoring campaign."
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