Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The nature of GRB980425 and the search for off-axis GRB signatures in
  nearby type Ib/c supernovae emission   The identification of type Ib/c supernovae as GRB progenitors is motivated by
the association of GRB980425 with SN1998bw and of GRB030329 with SN2003dh.
While the gamma-ray luminosity of GRB030329 was typical to cosmological GRBs,
the luminosity of the nearby (40 Mpc) GRB980425 was ~5 orders of magnitude
lower. The large luminosity difference is commonly explained by hypothesizing
that either SNe Ib/c produce two different classes of GRBs, or that GRB980425
was a typical cosmological GRB jet viewed off-axis. In the latter scenario,
strong radio emission, ~10^{30} erg/s Hz, is expected at ~1 yr delay due to jet
deceleration to sub-relativistic speed, as observed from GRB970508. The radio
luminosity of SN1998bw was 3 orders of magnitude lower than this value. We show
that the low radio flux may be consistent with the off-axis jet interpretation,
if the density of the wind surrounding the progenitor is lower than typically
expected, \dot{m}=(\dot{M}/10^{-5} M_sun/yr)/(v/10^3 km/s)~0.1 instead of
\dot{m}>=1. The lower value of \dot{m} is consistent with the observed radio
emission from the supernova shock driven into the wind. This interpretation
predicts transition to sub-relativistic expansion at ~10 yr delay, with current
\~1 mJy 10GHz flux and m_V~23 optical flux, and with ~10 mas angular source
size. It also implies that in order to search for the signature of off-axis
GRBs associated with nearby Ib/c supernovae, follow up observations should be
carried on a multi-yr time scale.

32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex