Relativistic reconnection

Yuri Lyubarsky

Ben-Gurion University, Israel

12

2

4

cB

enB 8

8

2BnT

cenj 2vcurrent

current sheet

221

8

2

mcT mB

4cBj

enB

eBT

Br 8

B j

l

lR

eLmc

eBlmc

leBmc

leBT

lr B

2/1

5.222

'''''

ll '

RlBB 0

clBL 220

/' BB

02/1

5.2

''

RR

eLmc

lr B

1 ;1'' lr B

2/138

102/1 1035.2 LL mm

mce

lR e

shock

j j

2no dissipation:

2

1

1

2

''

n

n

enB

enB

Br 8'8'' ll '

l

shock

j j

32

45

23/2

23/2

v ;

;

;

0

000

0

crl

rl

rl

rl

rl

negligible dissipation

partial dissipation

total dissipation

eBmcr 1

2

0

l

RlBB 0

2

2

5.2

2/1

20

41 ;c

BmceL

mc

leBlR

Total dissipation of alternating fields at the shock if

In pulsars 63 10...10...120 mc

leB

5.2

2/1

0 mceL

lR Total dissipation in a freely expanding flow at

Termination shocks in PWNe at lR

Bow shocks in binary pulsars at lR 310Dissipation at shocks in AGNs: Levinson & van Putten 1997

in GRBs: Fan, Wei & Zhang 2004

;)2/1( cPl

Particle acceleration: talks by Drake and Hoshino

1 ; pN p 021 p

resistivity

inflow

outflow

'' lr B Reconnection at

Rl '

jet with tangled magnetic fields (Heinz & Begelman 2000)

current sheet in the pulsar wind

Petschek reconnection

1 tanv / 2

2 21 cos

2 8Bp

2 cos

3sin

2 cos

1211

21

4

B

2cos4cos2T

212 cos2

slow shock

tan v;ln1)0,0( in

tan20 cBB l

x

clc 1.0v )/ln(4in

Time dependent reconnection: Tolstykh, Semenov & Heyn, poster 48

Relativistic Petschek reconnection in case 0zB

, 0z inB B

0in, v BBB youtz

10

, B

B inz

,0

z out

out

BB

1

0 2

2 20 ,in z outB B v

1/out

energy balance

pressure balance

0in, v BB outz

2

40 3 2

2.

sout

routz

h

B

B0

Bz,out

vin

out

2inv

10

, B

B inz

reconnection force-free MHD turbulence

cascade dissipation

Thompson & Blaes 1998; Troischt & Thompson 2004; Cho 2005; Luo & Melrose 2006

Conclusions

1. In freely expanding outflows, r’B/l’ grows with the distance; however total dissipation of alternating field generally

occurs at too large distance 2 .Dissipation at the termination shock is a plausible

mechanism, at least in pulsar winds

3 .Fast reconnection of tangled field is possible if l’<R/At >>1, magnetic energy is generally not transferred

to the plasma. Dissipation via turbulent MHD cascade?