1. GRB-Supernova observations: State of the art
Probing the Supernova Mechanism by Observations July 2012
GRB-Supernova observations:
State of the art
Elena Pian
INAF, Trieste Astronomical Observatory &
Scuola Normale Superiore di Pisa, Italy

2. GRBs are brief flashes of soft -ray radiation (100 keV), discovered in the 1970’s, the origin of which was not known
until 1997
CGRO-BATSE

3. The GRB distribution is isotropic

4. GRB970228: first detection of X-ray and optical afterglow
8 hours
3 days
Van Paradijs et al. 1997
6 months
later
Costa et al. 1997

5. Fields of GRBs (physical scale across each image is about 7 kpc)
Starling et al. 2011

6. Early Multiwavelength Counterparts
(z = 0.937)
(z = 6.29)
(z = 1.6)
Bloom et al. 2008

7. Different progenitors: SNe
long
Bimodal
distribution
of GRB
durations
short
Different progenitors: SNe
vs binary NS mergers
Duration (s)
Kulkarni 2000

8. Isotropic irradiated –ray energy vs redshift
Long GRB
Short GRB

9. Relativistic jet model of a GRB:
“Unified scheme” for GRBs and Sne?

10. GRB980425
Supernova 1998bw (Type Ic)
z =
Galama et al. 1998

11. GRB-Supernovae with ESO VLT+FORS
GRB031203/SN2003lw
z = 0.168
z = 0.105
Malesani et al. 2004
GRB-SNe have kinetic energies
exceeding those of normal SNe by
an order of magnitude (e52 erg)
Hjorth et al. 2003

12. X-ray Flashes

13. Swift was triggered by XRF060218 on Feb 18.149, 2006 UT
Campana et al. 2006
Prompt event
afterglow
UVOT SN
z = 0.033
Shock breakout or jet cocoon interaction with CSM,
Or central engine, or synchrotron + inverse Compton ?

14. Mass of remnant is compatible With neutron star rather than Black hole
SN2006aj (z = 0.033)
M(56Ni) = 0.2 Msun
M(progenitor) = 20 Msun
Mass of remnant is compatible
With neutron star rather than
Black hole
Pian et al. 2006; Mazzali et al. 2006; Ferrero et al. 2006

15. X-ray light curves of low-redshift GRBs
Starling et al. 2011

16. Shock breakout in SN2010bh (Cano et al. 2011)
Starling derives an initial radius of 8e11 cm from X-ray spectroscopy

17. GRB/XRFs associated with supernovae
Zhang et al. 2012, arXiv:

18. z = 0.28

19. GRB120422A/SN2012bz (z = 0.283)
26 April 2012
Perley et al. 2012

20. VLT FORS spectra of GRB120422A/SN2012bz
SN1998bw
SN2006aj

21. GRB091127/SN2009nz (z = 0.49)
Berger et al. 2011
Cobb et al. 2010

22. Light Curves of GRB and XRF Supernovae at z < 0.3
Melandri et al. 2012

23. Photospheric velocities of Type Ic SNe
Pian et al. 2006
Bufano et al. 2012

24. Properties of GRB-SNe
Berger et al. 2011

25. light curves of the optical afterglow of the
“normal” long GRB (z = 0.125)
Gal-Yam et al. 2006
Della Valle et al. 2006

26. spectra of GRB060614 (z = 0.125): no SN features
GMOS, 15 Jul 06
VLT, 29 Jul 06
Gal-Yam et al. 2006
Della Valle et al. 2006

27. -14 Light curves of Ic SNe: GRB-SNe, broad-lined SNe, normal SNe
Della Valle et al. 2006
Fynbo et al. 2006
Gal-Yam et al. 2006
GRB060614
GRB060505

28. Summary
Most long GRBs and XRFs are associated with energetic spectroscopically identified Type Ic Sne. SNe associated with GRBs are more luminous than XRF-SNe
Mechanisms:
Collapsar: a BH forms after the core collapses, and rapid accretion on it feeds the GRB jet.
Magnetar: the NS spin-down powers a relativistic jet
Not all long GRBs are accompanied by energetic Type Ic Sne
Is the early high energy emission due to an engine (jet) or to shock breakout? Late time SN spectroscopy may be a tool to investigate this
via reconstruction of supernova explosion geometry (VLT; Subaru)