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Transition to quark matter and Gamma-Ray-Bursts

Transition to quark matter and Gamma-Ray-Bursts. Alessandro Drago – University of Ferrara Main collaborators: Zurab Berezhiani (L’Aquila) Ignazio Bombaci (Pisa) Filippo Frontera (Ferrara) Andrea Lavagno (Torino) Giuseppe Pagliara, Irene Parenti. Temporal structure of GRBs.

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Transition to quark matter and Gamma-Ray-Bursts

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  1. Transition to quark matter and Gamma-Ray-Bursts Alessandro Drago – University of Ferrara Main collaborators: Zurab Berezhiani (L’Aquila) Ignazio Bombaci (Pisa) Filippo Frontera (Ferrara) Andrea Lavagno (Torino) Giuseppe Pagliara, Irene Parenti

  2. Temporal structure of GRBs 0. Supernova explosion and then… (delay ? how long?) • Precursor  delay… • Main event with quiescent times • Early X-ray afterglow, plateau and flares

  3. Quiescent time

  4. Early x-ray afterglowZhang et al. astro-ph/0508321 Plateau and flare

  5. Mass -- radius relation of neutron stars,of hyperonic and of quark stars Two types of quark matter: Normal quark matter and Color Superconducting quark matter Hundreds of papers on Color Superconducting quark matter!

  6. Quark droplet nucleation time“mass filtering” Berezhiani, Bombaci, Drago, Frontera, Lavagno ApJ 586 (2003) 1250 Critical mass for s = 0 B1/4 = 170 MeV Critical mass for s = 30 MeV/fm2 B1/4 = 170 MeV Age of the Universe! Mass accretion

  7. Energy released in the HSHyS(QS) convertionA.D., A.Lavagno, G.Pagliara, PRD69(2004)057505 CFL gaps Based on the “simple” scheme of Alford and Reddy PRD67(2003)074024

  8. Detonation or deflagration?A.D., A.Lavagno, I.Parenti, astro-ph/0512652 Main results:  Never a detonation (no mechanical shock)  Always a deflagration with an unstable front  Convection can develop if hyperons are present in the hadronic phase or if diquark can condensate

  9. How to generate GRBs main emission The energy released (in the strong deflagration) is carried out by neutrinos and antineutrinos. A reaction that can generate gamma-ray is: The efficency of this reaction in a strong gravitational field is up to: [J. D. Salmonson and J. R. Wilson, ApJ 545 (1999) 859] For bare quark stars direct photon emission can be even more efficent! See previous talk by Pawel Haensel

  10. Cumulative distribution of quiescent timesE.Nakar and T.Piran, MNRAS 331 (2002) 40data from Batse catalog Lognormal distribution “… the quiescent times are made by a different mechanism then the rest of the intervals” Nakar and Piran 2002

  11. Temporal structure of BATSE 5486

  12. Analysis of time intervals between peaks within each emission episod A.D., G.Pagliara, astro-ph/0512602 Same temporal micro-structure within each emission episod

  13. Analysis of durations of the two emission episods a) and within each episode b) The second active period lasts on the average twice the first active period Why? In the collapsar model this would imply that the second fragment of the disk is larger than the first… What sets the scale??

  14. Phase diagram of neutral quark matter: effect of neutrino trappingRuster et al. PRD73 (2006) 034025 Formation of color superconducting quark matter from normal quark matter takes place through a first order transition. The energy released in the second transition is larger than in the first!

  15. Including also the precursor… Formation of strangeness inside the star, triggering the formation of quark matter Low density: Hyperons - Kaon condensates…

  16. Temporal structure of GRBsin the quark deconfinement model 0. Supernova explosion  neutron-proton star and then… (delay, mass accretion) • Precursor (formation of strangeness)  delay… • Main event (formation of normal quark matter), quiescent time, then... formation of superconducting quarks No need to inject energy continously during the precursor and the main event! • Early X-ray afterglow, plateau and flares (differential rotation, expulsion of the toroidal magnetic field, Haensel et al. in preparation, see previous talk)

  17. Conclusions • The conversion of an hadronic star into a hybrid or quark star can be at the origine of (at least part of) the long GRBs. • While in the collapsar model SN explosion and GRB need to be almost simultaneous, in the QM formation model a time delay between SN and GRB can exist, and its duration is regulated by mass accretion. • The formation of diquark condensate can significantly increase the total energy released. “Evidence” of two active periods in long GRBs. The first transition, from hadronic matter to unpaired (or 2SC) quark matter acts as a “mass filter”. The second transition, producing (g)CFL quark matter can be described as a decay having a life-time of order tens of seconds

  18. QM formation after deleptonization and cooling Pons et al. PRL 86 (2001) 5223

  19. Droplet potential energy: Quantum nucleation theory I.M. Lifshitz and Y. Kagan, Sov. Phys. JETP 35 (1972) 206 K. Iida and K. Sato, Phys. Rev. C58 (1998) 2538 nQ* baryonic number density in the Q*-phase at a fixed pressure P. μQ*,μHchemical potentials at a fixed pressure P. σ surface tension (=10,30 MeV/fm2)

  20. Detonation or deflagration? Continuity eqs. through the front Energy momentum tensor Baryon flux

  21. Scheme for convection

  22. M.Alford, D.Blaschke, A.D., G.Pagliara, J.Schaffner-Bielich, in preparation

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