SN 2003L

K. Hurley and T. Cline, on behalf of the Ulysses, HETE, Mars Odyssey,
and KONUS GRB teams,

E. Mazets and S. Golenetskii, on behalf of the Konus-Wind GRB team,

D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger, W.
Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team,

A. von Kienlin, G. Lichti, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team,

I. Mitrofanov, D. Anfimov, A. Kozyrev, M. Litvak and A. Sanin, on
behalf of the HEND-Odyssey GRB team,

W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on
behalf of the GRS-Odyssey GRB team, and

G. Ricker, J-L Atteia, N. Kawai, D. Lamb, S. Woosley, J. Doty, R.
Vanderspek, J. Villasenor, G. Crew, G. Monnelly, N. Butler, J.G.
Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R.
Manchanda, G.  Pizzichini, Y. Shirasaki, C. Graziani, M. Matsuoka, T.
Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi,
T. Tavenner, T.  Donaghy, M. Boer, J-F Olive, and J-P Dezalay, on
behalf of the HETE GRB team, report:

We have searched the IPN data for a gamma-ray burst that might be
associated with SN2003L (Boles, IAUC 8048; Valenti et al., IAUC 8057;
Kulkarni et al., IAUC 8061; Kulkarni & Fox, IAUC 8073).  It has been
suggested by Soderberg et al. (GCN 1834
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 ) that SN2003L is actually a
hypernova, and might therefore be similar to SN1998bw/GRB980425.  We
have limited our search to data obtained between November 10 2002 and
January 10 2003.  The missions and experiments in the IPN were Ulysses,
Konus-Wind, RHESSI, Mars Odyssey (HEND and GRS), HETE-2 (FREGATE), and
INTEGRAL (SPI-ACS).  The data on 41 bursts and candidate (unconfirmed)
bursts were examined.  During that period, no burst which could be
localized by the IPN was found to have a source position in any way
consistent with that of the supernova.  That is, there was no event
observed by two or more spacecraft that produced a source annulus or
error box consistent with the supernova.  Several events were observed
each by single spacecraft in the network during this time.  Most of
them can be ruled out as counterparts because of the coarse
localization capabilities of the experiments involved.  However, two such
events had positions which were not inconsistent with the position of
SN2003L.  One occurred on 021213 at 41739 s, and was detected only by
HETE-FREGATE.  Based on Earth-blocking considerations, the probability
of a chance association with SN2003L is ~70%.  This burst had a fluence
of roughly 10^-6 erg/cm^2.  The other occurred on 021228 at 53801 s and
was detected only by Konus-Wind.  Based on the ecliptic latitude
response of the Konus detectors, the probability of a chance
association is ~17%.  This burst had a fluence of ~2x10^-6 erg/cm^2.

Lacking any definite evidence for an association, we can give
an  upper limit to the fluence of a GRB from SN2003L. This limit
depends on the duration, spectrum, and arrival time within the search
window, all of which are unknown (see Hurley et al. GCN 1252
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 ), but can
be roughly taken to be several times 10^-7 erg/cm^2 in the energy range
above 25 keV.

SN2003L is about 2.6 times more distant than SN1998bw.  Neglecting
beaming and other event-to-event variations, any associated GRB might
be expected to be 7 times less intense, and possibly undetectable by
IPN instruments.

T. Matheson, P. Challis, R. P. Kirshner (CfA) and P. M. Garnavich
(Notre Dame)

We obtained spectra of the type Ic SN 2003L (IAUC 8048; GCN 1834
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 ) with
the MMT 6.5m telescope and the Blue Channel spectrograph on Jan 29.46
UT.  Two 600s exposures have a resolution of 0.6 nm and cover the
wavelength range 320 to 880 nm.  The supernova appears to be a normal
type Ic, similar to SN 1994I near maximum.  Expansion velocities
derived from the minima of the Ca II (rest 395.1 nm) and Na I D (rest
589.3 nm) lines are 12 000 km/s and 11 700 km/s, respectively.  At 4
days before maximum, SN 1994I had a velocity of 16 100 km/s for Ca II
and 11 100 for Na I.  As has been noted already (IAUC 8057), the
expansion velocity derived from the Si II (rest 635.5 nm) line of 5200
km/s is quite low, compared with 12 200 km/s for SN 1994I (at four
days before maximum).  The Si II line velocity was larger than 12 000
km/s for the first twenty days after explosion for SN 1998bw, well
above the value for SN 2003L.  The spectrum is available at
http://cfa-www.harvard.edu/cfa/oir/Research/supernova/RecentSN.html.

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A. M. Soderberg, E. Berger, S. R. Kulkarni and D. A. Frail report

"We have observed the type Ic SN 2003L (IAUC 8048) with the VLA on Jan
26.23 UT. We find a bright radio source at the optical position of the
supernova with a flux of 1.4 mJy at 8.5 GHz.  An additional epoch on
Jan 28.22 UT confirms the transient nature of the radio source.  SN
2003L has a radio luminosity approaching that of SN 1998bw, suggesting
that the ejecta are possibly relativisitic.  Such brilliant radio
luminosity at early times is rare. Thus, further observations, in
particular optical spectroscopy (for broad lines), optical monitoring,
X-ray observations, and searches for gamma-ray emission towards the SN in
archival data are highly desirable. We plan to continue monitoring the
source at the VLA over the next few months."

This message may be cited.