Multi-wavelength multi-site

Monitoring of Gamma-Ray

Burst-associated Supernovae

19 July 2012

Burst-associated Supernovae

Elena Pian

INAF-Trieste Astronomical Observatory and

Scuola Normale Superiore di Pisa, Italy

GRBs are brief flashes of soft γ-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

8 hours 3 days

GRB970228: first detection of X-ray and optical afterglow

Van Paradijs et al. 1997

6 months

later

Costa et al. 1997

t−1.3

HST Fields of GRBs

(physical scale across each image is about 7 kpc)

Starling et al. 2011

Isotropic irradiated γγγγ–ray energy vs redshift

Long GRB

Short GRB

Early Multiwavelength Counterparts

(z = 0.937)(z = 6.29)

(z = 1.6)

Bloom et al. 2008

Bimodal

distribution

of GRB

durations

short

long

Different Different

progenitors:

SNe

vs binary NS

mergers

Kulkarni 2000Duration (s)

GRB980425

Supernova 1998bw (Type Ic)

z = 0.0085

Galama et al. 1998

GRB-Supernovae with ESO VLT+FORS

z = 0.168

GRB031203/SN2003lw

z = 0.105

GRB-SNe have kinetic energies

exceeding those of normal SNe by

an order of magnitude (e52 erg)Hjorth et al. 2003

Malesani et al. 2004

X-ray Flashes

Swift was triggered by XRF060218 on Feb 18.149, 2006 UT

Prompt

event

afterglow

Campana et al. 2006

UVOT

Shock breakout or jet cocoon interaction with CSM,

Or central engine, or synchrotron + inverse Compton ?

SN

z = 0.033

M(56Ni) = 0.2 Msun

M(progenitor) = 20 Msun

Mass of remnant is compatible

With neutron star rather than

Black hole

SN2006aj (z = 0.033)

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 (z = 0.059)

Gemini-South, Faulkes telescope, HST

Cano et al. 2011

SN2010bh (z = 0.059)

PROMPT, VLT/FORS, VLT/XS

Gemini-S/GMOS and Magellan Echellette

Bufano et al. 2012Chornock et al. 2010

SN2010bh (z = 0.059)

FORS and X-Shooter spectra

Bufano et al. 2012

z = 0.283

GRB120422A/SN2012bz (z = 0.283)

26 April 2012

Perley et al. 2012

VLT FORS spectra of GRB120422A/SN2012bz

z = 0.283

SN1998bw

SN2006aj

Melandri et al. 2012

Light Curves of GRB and XRF Supernovae at z < 0.3

Melandri et al. 2012

Photospheric velocities of Type Ic SNe

Pian et al. 2006Bufano et al. 2012

GRB091127/SN2009nz (z = 0.49)

Cobb et al. 2010 Gemini/GMOS, Berger et al. 2011

UVOT

XRF080109/SN2008D (25 Mpc)

Gemini/GMOS

Palomar 60in

S-LOTIS

Swift/XRT

Soderberg et al. 2008

XRT observations

Of XRF080109

~e46 erg

VLT FORS spectra of SN2008D:

Broad lines disappear near main maximum and at the same time He lines develop: the He envelope brakes the high velocity material and prevents the formation of a powerful jet

Broad lines

Mazzali et al. 2008

He lines

Props of SNe Ibc as f(Mprog)

2010bh

SN 2012bz/

GRB120422A

SN 2012bz/

GRB120422A

2010bh

A minimum mass and energy seem to be required for GRBs:

Need more data and analysis to understand trend(Courtesy: P.Mazzali; K. Nomoto)

Summary and open problems

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. feeds the GRB jet. Magnetar: the NS spin-down powers a relativistic jet

Is the early high energy emission due to an engine (jet) or to shock breakout?

Not all Type Ic SNe make GRBs. Can these be misaligned with Respect to the line of sight?