GRB-Supernova observations: State of the art Probing the Supernova Mechanism by Observations 16 July 2012 GRB-Supernova observations: State of the art Elena Pian INAF, Trieste Astronomical Observatory & Scuola Normale Superiore di Pisa, Italy

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

The GRB distribution is isotropic

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

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

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

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

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

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

GRB980425 Supernova 1998bw (Type Ic) z = 0.0085 Galama et al. 1998

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

X-ray Flashes

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 ?

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

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

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

GRB/XRFs associated with supernovae Zhang et al. 2012, arXiv:1206.0298

z = 0.28

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

VLT FORS spectra of GRB120422A/SN2012bz SN1998bw SN2006aj

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

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

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

Properties of GRB-SNe Berger et al. 2011

light curves of the optical afterglow of the “normal” long GRB060614 (z = 0.125) Gal-Yam et al. 2006 Della Valle et al. 2006

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

-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

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)