lvii congresso sait - bologna, 7-10 maggio 2013 …rifatto/sait_2013/ghirlanda.pdf · changing...
TRANSCRIPT
Changing perspective in the study of
Gamma Ray Bursts!{… Unraveling some mysteries and adding new ones} !
Giancarlo Ghirlanda!INAF – Osservatorio Astronomico di Brera !
LVII Congresso SAIt - Bologna, 7-10 maggio 2013!
M. G. Bernardini, D. Burlon, A. Celotti, S. Campana, S. Covino, P. D’Avanzo, G. Ghisellini, A. Melandri, L. Nava, R. Salvaterra, G. Tagliaferri, S. D. Vergani!
Ghirlanda et al. 2012, MNRAS, 420, 483!Ghirlanda et al. 2013, MNRAS, 428, 1410!
PRIN-INAF 2011: “Four steps forward in undesrstanding Gamma Ray Bursts” !(P.I. Ghirlanda)!
Rela%vis%c ou-low
What a Gamma Ray Burst is!
“internal” shock: prompt emission
Ø γ-‐ray/hard-‐X Ø T=1-‐100s Ø Variable Ø E~1049-‐1054 erg
“external” shock: AFerglow emission
Ø X, Opt/NIR, Radio Ø up to hundred of days Ø Smooth decay
ISM!
ISM!
ISM!
ISM!
ISM!
ISM!
Observer Frame
Fluences, Fluxes etc.
< 1997: No redshift
Observer Frame
Fluences, Fluxes etc.
< 1997: No redshift
> 1997 redshift
Rest Frame
Observer Frame
Fluences, Fluxes etc.
< 1997: No redshift
> 1997 redshift
Rest Frame
Now à Γ0 Comoving
Frame
?
Observer Frame
Fluences, Fluxes etc.
Rest Frame
? Comoving
Frame
< 1997: No redshift
> 1997 redshift
Now à Γ0
Ghirlanda et al. 2012, MNRAS, 420, 483
Changing perspective!from the rest frame to the comoving frame!
Comoving frame !properties cluster!
Rest frame
Comoving frame ��2
0
0.07 dex
Ghirlanda et al. 2012, MNRAS, 420, 483
Ghirlanda et al. 2012, MNRAS, 420, 483
Changing perspective!from the rest frame to the comoving frame!
Rest frame
Comoving frame ��2
0
0.07 dex
Comoving frame !properties cluster!
A unified explanation of GRB correlations!
€
Eiso ∝Γ01.96±0.26
€
Liso ∝Γ02.04±0.22
€
Epeak ∝Γ01.31±0.31
(e.g. Tcheckolskoy, Narayan et al. 2010, 2012)
Epeak
/ E0.5iso
Epeak
/ L0.5iso
[Amati et al. 2002 …] !
[Yonetoku et al. 2004 …] !
Ghirlanda et al. 2012, MNRAS, 420, 483
E� = Eiso
✓2jet
= �20✓
2jet / Epeak
if ✓2jet�0 = const
E� / Epeak[Ghirlanda+2004, Nava+2006] !
The “faster” … the “narrower”!
✓2jet / 1/�0
Monte Carlo Population
SYnthesis Code (PSYC)!Ghirlanda et al. 2013, MNRAS, 428, 1410
There is a link between geometry (θjet) and dynamics (Γ0)
Monte Carlo Population
SYnthesis Code (PSYC)!Ghirlanda et al. 2013, MNRAS, 428, 1410
… among other results … !GRB true rate !
SN Ibc [Grieco et al., 2012, MNRAS, 423, 3049]
Long GRBs
Monte Carlo Population SYnthesis Code
and Hydrodynamic Emission model !
(PSYCHE)!Ghirlanda et al. 2013
Predictions for radio observations
of GRBs in the
SKA era !
See Poster !
1. Thermal vs non-thermal!
2. Dissipative efficiency!3. Variability!4. Precursors!
1. Environment structure!2. Afterglow parameters!3. Pair enrichment!4. Radio calorimetry!
1. Jet structure!2. Pre-acceleration!3. Radiative fireball !4. Off axis GRBs!
1. Low luminosity GRBs!2. Pop-III GRBs!3. Luminosity function !4. High z GRBs!
Some on-going projects!
1. Intrinsic energetic/luminosity!
2. Link between geometry and dynamics!
1. BH accretion !2. Jet dynamics!3. Magentars!
971019
990123
Kippen et al. 1997
Briggs et al. 1999
10-8
10-7
10-8
10-7
10-6νF�
(erg ￲ cm
-2￲ s-1)
10
0 101 102 103 104 105
Photon Energy ( keV)
GRB 990123(Briggs et al. 1999)
XRF 971019(Kippen et al. 2002)
Flue
nce
(erg
/cm
2 ) 971019
990123
Prompt spectrum:!non-thermal!!
Ghirlanda+2003 A&A!Ryde et al. 2005, ApJ!
Guiriec et al. 2011, APJ !
Ghirlanda, Pescalli, Ghisellini, 2013, MNRAS, 432, 3237
Ghirlanda+2003 A&A!Ryde et al. 2005, ApJ!
Guiriec et al. 2011, APJ !
Only 4 before Fermi. !!New one in Fermi ![Ghirlanda, Pescalli, Ghisellini et al. 2013 MNRAS in press]!
Only 4 before Fermi. !!New one in Fermi ![Ghirlanda, Pescalli, Ghisellini et al. 2013 MNRAS, 432, 3237]!
10rg
Q2: Why non-thermal emission is absent ? !
Q1: Why?!
Thanks!