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

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 .