Spectral Lag and Flares in Gamma-Ray Bursts: Dynamics and Energetics Analysis

1. GRB 060418 and GRB 060607A the flares and the spectral lag M.G. Dainotti M.G.Bernardini, C.L.Bianco, L. Caito, R. Guida, R.Ruffini

2. Transparency point in which γasym= 1\B (ABM pulse) Afterglow peak emission II: collision with the baryonic remnants III: PEMB-pulse expansion Ultrarelativistic regime I: PEM-pulse expansion Relativistic regime the dynamics of the process …

3. At transparency point: The percentage of PEMB Pulse internal energy converted into baryonic kinetic energy rises with rising B. B=2*10^-3 in this source. Ruffini, Salmonson, Wilson, Xue, A&A, 359, 855, (2000) Ruffini, Bianco, Chardonnet, Fraschetti, Vitagliano, Xue, “Cosmology and Gravitation”, AIP, (2003)

4. ΔE is the internal energy developed in the collision with the CBM T: temperature of the black body in the comoving frame the Stefan Boltzmann costant The ratio between effective emitting area and visible area :it takes into account of CBM filamentary structure (the so called surface filling factor) The ratio is a priori a function of the radial coordinate.

5. T90= 50 z= 1.489 Eγ= 9* 10^52, FIR,peak= 50mJy tIR,peak =153s Eγ is the isotropic-equivalent prompt gamma-ray energy. For GRB 060418 and 060607A there are measurements of the near infrared afterglows with REM robotic telescope Observational features of 060418

6. we find a constant and low-density medium profile for GRB 060418 and GRB 060607A, which is consistent with the inference from the late afterglow data. • The early time afterlow lightcurve carries information on Гo =400, fully confirming the highly relativistic nature of the fireball • (Molinari et al.2007)

7. Parameters of GRB 060418 • Dyadosphere energy: 2.34e55 erg Lorentz gamma factor: 490 higher than the observational Гo (400) P-GRB laboratory energy: 1.22e-02 Edya Total number of pairs: 5.6e59 Plasma temperature: 2.53MeV Dainotti et al. in preparation

8. The global lightcurve of 060418 Dainotti et al. in preparation

9. The Bat lightcurve P-GRB Dainotti et al. In preparation

10. There is no spectral lag between the theoretical γ peak and X peak. They both occur at 26 s

11. The XRT lightcurve Dainotti et al. in preparation

12. The global lightcurve without a flare

13. The γ-ray lightcurve

14. The X-rays lightcurve

15. GRB 060607A BAT lc: initial spikelike emission ~ 15 s XRT lc: canonical behavior + flaring activity Peak of the IR emission observed by REMIR z = 3.082 Γ0 ~ 400 Molinari et al. 2007, A&A, 469, L13. Covino et al., arXiv:0710.0727.

16. GRB 060607A • Etote±= 2.5 x 10^53 erg • B = 3.0 x 10-3 • Ne± = 2.6 x 10^58 • T = 1.7 MeV • γ0 = 330 LCs well reproduced γ0 compatible with the estimates Bernardini et al. in preparation Molinari et al. 2007, A&A, 469, L13. Covino et al., arXiv:0710.0727.

17. Details on the LCs Prompt emission: <nCBM> = 0.1 #/cm3 X-Ray Afterglow: Molinari et al. 2007, A&A, 469, L13. Guidorzi, private communication. Vergani, private communication. Bernardini et al. in preparation

18. Still there are some problems A: δn/n ~ 800 Δr ~ 2x10^15 cm B: δn/n ~ 10 Δr ~ 3x10^16 cm A B Failure in reproducing the observed δt/t: maybe full 3d treatment needed! Bernardini et al. in preparation

19. The CBM behavior Decreasing particle distribution: fragmentation of fireshell? Sharp increase of the emitting area? Dainotti et al., 2007, A&A, 471, L29.

20. The comparison between the two sources • In GRB 060418 the energy and Г are overestimated • while in the GRB 060607A the value of Г is understimated. • The densities of GRB 060607 are in good agreement with the observations • While in 060418 the density mask is still incomplete and it is not constant.

21. It is still a preliminary result! There are problems on the energetics much higher than the experimantal probably due to a misleading individuation of the P-GRB .