1. Gamma-Ray-Bursts in Nuclear Astrophysics Giuseppe Pagliara Dip. Fisica Politecnico di Torino INFN-Ferrara XI Convegno su Problemi di Fisica Nucleare Teorica - Cortona 2006

2. General features of GRBs  Duration 0.01-1000s  ~ 1 burst per day (BATSE)  Isotropic distribution rate of ~2 Gpc -3 yr -1  Isotropic distribution - rate of ~2 Gpc -3 yr -1  ~100keV photons  Cosmological Origin  The brightness of a GRB, E~10 51 ergs (beaming effect), is comparable to the brightness of the rest of the Universe combined. Very complex time-structure

3. “Two kinds of precursors” SN-GRB connection, time delays from second to years Prompt-emission precursor, few hundred of seconds

4. Rotating massive stars, whose central region collapses to a black hole surrounded by an accretion disk. Rotating massive stars, whose central region collapses to a black hole surrounded by an accretion disk. Outflows are collimated by passing through the stellar mantle. Outflows are collimated by passing through the stellar mantle. Detailed numerical analysis of jet formation. Detailed numerical analysis of jet formation. Fits naturally in a general scheme describing collapse of massive stars. Fits naturally in a general scheme describing collapse of massive stars. - Large angular momentum needed, difficult to achieve. - Large angular momentum needed, difficult to achieve. SN – GRB time delay: less then 100 s. SN – GRB time delay: less then 100 s. Can it explain long time delay precursors ? The Collapsar model

5. The Quark-Deconfinement Nova model

6. I.M. Lifshitz and Y. Kagan, Sov. Phys. JETP 35 (1972) 206 K. Iida and K. Sato, Phys. Rev. C58 (1998) 2538 I.M. Lifshitz and Y. Kagan, Sov. Phys. JETP 35 (1972) 206 K. Iida and K. Sato, Phys. Rev. C58 (1998) 2538 Droplet potential energy: n Q* baryonic number density in the Q*-phase at a in the Q*-phase at a fixed pressure P. fixed pressure P. μ Q*,μ H chemical potentials at a fixed pressure P. at a fixed pressure P. σ surface tension (=10,30 MeV/fm 2 ) (=10,30 MeV/fm 2 ) n Q* baryonic number density in the Q*-phase at a in the Q*-phase at a fixed pressure P. fixed pressure P. μ Q*,μ H chemical potentials at a fixed pressure P. at a fixed pressure P. σ surface tension (=10,30 MeV/fm 2 ) (=10,30 MeV/fm 2 ) Quantum nucleation theory Delayed formation of quark matter in Compact Stars Quark matter cannot appear before the PNS has deleptonized (Pons et al 2001)

7. Quark droplet nucleation time “mass filtering” Critical mass for  = 0 B 1/4 = 170 MeV Mass accretion Critical mass for  = 30 MeV/fm 2 B 1/4 = 170 MeV Age of the Universe!

8. Two families of CSs Conversion from HS to HyS (QS) with the same M B

9. The reaction that generates gamma-ray is: The efficency of this reaction in a strong gravitational field is: [J. D. Salmonson and J. R. Wilson, ApJ 545 (1999) 859] The reaction that generates gamma-ray is: The efficency of this reaction in a strong gravitational field is: [J. D. Salmonson and J. R. Wilson, ApJ 545 (1999) 859] How to generate GRBs The energy released (in the strong deflagration see Parenti talk) is carried out by neutrinos and antineutrinos. The energy released (in the strong deflagration see Parenti talk) is carried out by neutrinos and antineutrinos.

10. Hadronic Stars  Hybrid or Quark Stars Z.Berezhiani, I.Bombaci, A.D., F.Frontera, A.Lavagno, ApJ586(2003)1250 Drago, Lavagno Pagliara 2004, Bombaci Parenti Vidana 2004… Metastability due to delayed production of Quark Matter. 1) conversion to Quark Matter (it is NOT a detonation (see Parenti )) 2) cooling (neutrino emission) 3) neutrino – antineutrino annihilation 4)(possible) beaming due to strong magnetic field and star rotation + Fits naturally into a scheme describing QM production. Energy and duration of the GRB are OK. Energy and duration of the GRB are OK. - No calculation of beam formation, yet. SN – GRB time delay: minutes  years SN – GRB time delay: minutes  years depending on mass accretion rate depending on mass accretion rate

11. Temporal structure of GRBs … back to the data ANALYSIS of the distribution of peaks intervals

12. Drago & Pagliara 2005 Excluding QTs Deviation from lognorm & power law tail (slope = -1.2) Probability to find more than 2 QT in the same burst Analysis on 36 bursts having long QT (red dots): the subsample is not anomalous

13. Analysis of PreQE and PostQE Same “variability”: the same emission mechanism, internal shocks

14. Same dispersions but different average duration PreQE:  20s PostQE:~40s QTs:~ 80s Three characterisitc time scales No evidence of a continuous time dilation

15. Interpretation: 1)Wind modulation model: during QTs no collisions between the emitted shells 2) Dormant inner engine during the long QTs Huge energy requirements No explanation for the different time scales It is likely for short QT Reduced energy emission Possible explanation of the different time scales in the Quark deconfinement model It is likely for long QT

16. Quiescent times in very long GRBs High red-shift

17. … back to the theory In the first version of the Quark deconfinement model only the MIT bag EOS was considered …but in the last 8 years, the study of the QCD phase diagram revealed the possible existence of Color Superconductivity at “small” temperature and large density

18. More refined calculations Two first order phase transitions: Hadronic matter Unpaired Quark Matter(2SC) CFL CFL cannot appear until the star has deleptonized Ruster et al hep-ph/0509073

19. Double GRBs generated by double phase transitions Two steps (same barionic mass): Two steps (same barionic mass): 1)transition from hadronic matter to unpaired or 2SC quark matter. “Mass filtering” 2) The mass of the star is now fixed. After strangeness production, transition from 2SC to CFL quark matter. Decay time scale τ few tens of second Nucleation time of CFL phase

20. Energy released Energy of the second transition larger than the first transition due to the large CFL gap (100 MeV) Bombaci, Lugones, Vidana 2006 Drago, Lavagno, Pagliara 2004

21. … a very recent M-R analysis Color superconductivity (and other effects ) must be included in the quark EOSs !!

22. Are LGRBs signals of the successive reassesments of Compact stars? Low density: Hyperons - Kaon condensates…

23. Conclusions A “standard model” the Collapsar modelA “standard model” the Collapsar model One of the alternative model: the quark deconfinement modelOne of the alternative model: the quark deconfinement model Possibility to connect GRBs and the properties of strongly interacting matter!Possibility to connect GRBs and the properties of strongly interacting matter! Collaborators: Alessandro Drago, Università Ferrara Andrea Lavagno, Dip. Fisica Politecnico di Torino

24. APPENDICI

25. Other possible signatures For a single Poisson process Variable rates SOLAR FLARES Power law distribution for Solar flares waiting times ( Wheatland APJ 2000 ) The initial masses of the compact stars are distributed near M crit, different central desity and nucleation times  of the CFL phase f(  (M)) Could explain the power law tail of long QTs ? Origin of power law:

26. Probability of tunneling