GRB 060418 and GRB 060607A the flares and the spectral lag

M.G. DainottiM.G. Dainotti

M.G.BernardiniM.G.Bernardini, C.L.Bianco, L. Caito, R. Guida, R.Ruffini , C.L.Bianco, L. Caito, R. Guida, R.Ruffini

the dynamics of the process …

I: PEM-pulse expansion

II: collision with the baryonic remnants III: PEMB-

pulse expansion

Transparency point in which γasym= 1\B (ABM pulse)

Afterglow peak emission

Ultrarelativistic regime

Relativistic regime

At transparency point:

The percentage of PEMB Pulse internal energy converted into baryonic kinetic energy rises with rising B.

Ruffini, Salmonson, Wilson, Xue, A&A, 359, 855, (2000)Ruffini, Bianco, Chardonnet, Fraschetti, Vitagliano, Xue, “Cosmology and Gravitation”, AIP, (2003)

B=2*10^-3 in this source.

ΔE is the internal energy developed in the collision with

the CBM

The ratio between effective emitting area and visible area :it takes into account of CBM filamentary structure (the so called surface filling factor)

the Stefan Boltzmann costant

The ratio is a priori a function of the radial coordinate.

AvisAeff

T: temperature of the black body in the comoving frame

R

R

424 TRrtE

Observational features of 060418• 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

• 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)

GRB060607ABA T lc: init ial spikelike emission ~ 15 sX RT lc: canonical behavior + fl ar ing act ivit yPeak of t he I R emission obser ved by RE M I Rz = 3 .082

0 ~ 400

M olinar i et al. 2007, A &A , 469 , L13 .Covino et al., ar X iv:0710 .0727 .

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: 2.53MeVDainotti et al. in preparation

The global lightcurve of 060418

Dainotti et al. in preparation

The Bat lightcurve

P-GRB

Dainotti et al. In preparation

There is no spectral lag between the theoreticalγ peak and X peak.

They both occur at 26 s

The XRT lightcurve

Dainotti et al. in preparation

The global lightcurve without a flare

The γ-ray lightcurve

The X-rays lightcurve

GRB060607ABA T lc: init ial spikelike emission ~ 15 sX RT lc: canonical behavior + fl ar ing act ivit yPeak of t he I R emission obser ved by RE M I Rz = 3 .082

0 ~ 400

M olinar i et al. 2007, A &A , 469 , L13 .Covino et al., ar X iv:0710 .0727.

BAT lc: initial spikelike BAT lc: initial spikelike emission ~ 15 semission ~ 15 sXRT lc: canonical behavior XRT lc: canonical behavior + flaring activity+ flaring activityPeak of the IR emission Peak of the IR emission observed by REMIRobserved by REMIRz = 3.082z = 3.082Γ0 ~ 400Γ0 ~ 400

Molinari et al. 2007, A&A, 469, L13.Molinari et al. 2007, A&A, 469, L13.Covino et al., arXiv:0710.0727.Covino et al., arXiv:0710.0727.

GRB 060607A

Etote±= 2.5 x Etote±= 2.5 x 10^53 erg10^53 ergB = 3.0 x 10-3 B = 3.0 x 10-3 Ne± = 2.6 x Ne± = 2.6 x 10^5810^58 T = 1.7 MeVT = 1.7 MeVγ0 =γ0 = 330 330

LCs well reproducedLCs well reproducedγ0 γ0 compatible with the estimatescompatible with the estimates

Molinari et al. 2007, A&A, 469, L13.Molinari et al. 2007, A&A, 469, L13.Covino et al., arXiv:0710.0727.Covino et al., arXiv:0710.0727.

Bernardini et al. in preparation

GRB 060607A

Details on the LCsDetails on the LCs

Prompt emission:Prompt emission: <nCBM> = 0.1 #/cm3<nCBM> = 0.1 #/cm3

X-Ray Afterglow:X-Ray Afterglow:

Molinari et al. 2007, A&A, 469, L13.Molinari et al. 2007, A&A, 469, L13.Guidorzi, private communication.Guidorzi, private communication.Vergani, private communication.Vergani, private communication. Bernardini et al. in preparation

Still there are some problemsStill there are some problems

AA

B

A: δn/n A: δn/n ~ 800~ 800 Δr ~ 2x10^15 cmΔr ~ 2x10^15 cmB: δn/n ~ 10B: δn/n ~ 10 Δr ~ 3x10^16 cmΔr ~ 3x10^16 cm

Failure in reproducing the Failure in reproducing the observed δt/t: observed δt/t: maybe full maybe full 3d treatment needed3d treatment needed!! Bernardini et al. in preparation

The CBM behaviorThe CBM behavior

Decreasing particle Decreasing particle distribution: fragmentation of distribution: fragmentation of fireshell?fireshell?

Sharp increase of the emitting Sharp increase of the emitting area?area?

Dainotti et al., 2007, A&A, 471, L29.Dainotti et al., 2007, A&A, 471, L29.

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.

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 .