GRB 031203

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GRB 031203 SN 2003lw
Daniele Malesani (SISSA Trieste) Gianpiero
Tagliaferri (INAF Milano Obs.) Stefano
Covino (INAF Milano Obs.) Guido
Chincarini (INAF Milano Obs.) Massimo Della
Valle (INAF Arcetri Obs.) Paolo Mazzali (INAF
Trieste Obs.) Luigi Stella (INAF Roma Obs.) et
many al........
On behalf of the Italian follow-up team
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GRB/SN connection the basics

• Association of GRBs with star formation

• Distribution of radial offsets

• GRB 980425 SN 1998bw (peculiar?)

• GRB 030329 SN 2003dh (less peculiar)

Stanek et al.Hjorth et al.
Galama et al. Patat et al.
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Observations of GRB 031203

• Trigger from INTEGRAL

Götz et al. 2003

• Observations at ESONTT (IR) VLT

• Afterglowradio (VLA) X-ray (XMM)

Frail 2003, Watson et al. 2004

• Very low redshift (z 0.1) Prochaska et al.
  2004Very faint E ? 10491050 erg Watson et al.
  2004High extinction E(BV) ? 1

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The X-ray ring
Bright impulsive source Large dust
column ? ExpandingX-ray ring (scattered
radiation)
Vaughan et al. 2004
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The NIR afterglow
Extinction corrected
SED 9 hoursafter the GRB The faintest
optical/NIR afterglow Two-components
SEDsynchro Compton?
X-ray data from Watson et al. 2004
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Searching for the SN
VLT FORS (Errors smaller than symbols)
See also Thomsen et al. Cobb et al. Gal-Yam
et al. Bersier et al.
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A very bright supernova
Galaxy subtracted ExtinctionE(B-V) 1.1 SN
2003lw brighterthan SN 1998bw by 0.5
magnitudes Broader maximum than SN
1998bw Simultaneity towithin a few days
SN 2003lw
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Spectroscopy of the host
VLT FORS12
Bright star-formation lines SFR ? 10
M?/y (Prochaska et al.Chincarini et al. in prep.)
Broad undulations
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Spectroscopic confirmation
Subtraction oflate-time spectrum Very broad
features Expansion velocities?15000
km/s Hypernova? Detailed spectral modeling in
progress(Mazzali et al. in prep.)
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Summary conclusions

• SN 2003lw was a bright hypernova.

• The three closest GRBs have a confirmed SN

• Do weak bursts have powerful SNe?

• How many weak bursts and how many SNe?

SN 2003lwvsSN 1998bw

• The ultimate connection

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Thats All Folks