magnetic reconnection at the termination shock in a striped pulsar wind yuri lyubarsky ben-gurion...

Magnetic reconnection at the termination shock in a striped pulsar

wind

Yuri LyubarskyBen-Gurion University, Israel

In collaboration with: Jerome Petri (now at Strasbourg Obs) Michael Liverts (BGU)

How the Poynting flux is transferred to radiating particlesin the nebula?

The answer (general): most of the energy is transferred by the waves; the waves decay.

Analytical model( Bogovalov 1999)

Numerical solution(Spitkovsky 2005)

The questions under discussion: where and how the waves decay?

The main goals of this talk:

1 .Find criterion for the dissipation of the waves at the at the pulsar wind termination shock.

2 .Demonstrate that in PWNe, the waves decay at the terminations shock unless they decayed in the wind.

3 .Apply the obtained criterion to the bow shocks in binary pulsar systems.

4 .Discuss the observational signatures of the wave decay at the shock front.

j j

Shock in a striped wind

1

''2

2

'2

ceB

TB

hr

2

2

1

1

cc nB

nB

l

v

; ; ;

222

251

3245

22

25

253/2

453/2

45

0

0

2

2

2

2

0

0

0

0

0

0

0

0

0

0

rl

ll

crl

rl

rl

rl

rl

negligible dissipation partial dissipation complete dissipation

j j

l1

1

21

0 eBmcr

2

2

4 cB

l2

The shock in a striped wind, 1.5D PIC simulations

203

2, /mcp yx

51082 N

55/ 0 rl

2, /mcp yx

2, /mcp yx

2045

2, /mcp yx

B

125/ 0 rl

2, /mcp yx

B

2, /mcp yx

B

2, /mcp yx

B

Condition for complete dissipation:

analytical 6.0 0

r

l

3 0

rl

numerical

2

2

4 cB

eB

mcr

2

0

cl

Alternating fields dissipate at the termination shockprovided the shock occurs at the distance

tymultiplici- / ;)3/2( GJ enRR L

In PWNe R/RL~109>>therefore even if the waves do notdissipate in the wind they do at the termination shock.

3 0

rl

Binary pulsars

secondary

shockpulsar wind

4L 108 km; 3.9 km; 2280 :63-1259 PSR aR

Double pulsar PSR J0737-3039. Modulation of the radio emissionfrom B with the period of A: alternating fields in the wind from Aare not erased completely.

300

km 700,000 km; 1000L

aR

PSR 1957+20 and PSR 1259-63: X-ray emission from the shockedplasma implies efficient dissipation of the Poynting flux.

10 km; 1700,000 a km; 77 :201957 PSR 4L R

Enigma of the radio emitting electrons in plerions

5.11 ; pN pThe acceleration process should somehow transfer most of the total energy of the system to a handful of particles leaving for the majority only a small fraction of the energy

Particle acceleration by forced annihilation of alternating magnetic fields

2.5 PIC simulations of the driven reconnection

0exp1

N

Evolution of the particle spectrum

Romanova & Lovelace 1992; Larrabee, Lovelace & Romanova 2002

0

exp1

N

22 EB

Conclusions

1 .In relativistic, Poynting dominated flows, alternating magnetic fields are dissipated at the shock front provided

3 0

1 rl

Under this condition, the downstream parameters are determined by the total energy flux and the mean magnetic field

2 .The condition for full magnetic dissipation is satisfied at the termination shock in the PWNe. In binary pulsars, the condition

for full dissipation imposes constraints on the pair multiplicity in the pulsar wind

3 .Particles are accelerated in the course of the driven reconnection;

0

exp1

N