relativistic jets in astrophysicspersonalpages.to.infn.it/~fre/rtignitor/pdfversie/...•shear...

Attilio Ferrari

CIFS Consorzio Interuniversitario per la Fisica Spaziale

Dipartimento di Fisica Generale, Università di Torino

INAF Osservatorio Astronomico di Torino

INFN, Sezione di Torino

RELATIVISTIC JETSRELATIVISTIC JETS

IN ASTROPHYSICSIN ASTROPHYSICSComputer simulations and experimental validationComputer simulations and experimental validation

Plasmas in Astrophysics and in the Laboratory - The Ignitor Challenge

Moscow, 20 - 21 June 2011

Highly nonlinear (relativistic) physics

Huge extension of physical parameters

Scalability

Astrophysical plasmas

Observations

Theoretical plasma physics

Numerical simulations

Laboratory plasma physics

Experiments and validation

GRS

3C279

Superluminal motions & Doppler boosting jet/counter-jet(Cohen et al. 1971, Biretta et al. 1999, Mirabel et al 1992)

Astrophysical Evidence of

Relativistic Jets

Jets and VHE Sources Variabilities

• Blazars, energetics (Oke & Gunn 1974)

• VHE emission and rapid variabilities correlated with Xrays and radio emission– Mkn 421 (AGILE, Donnarumma et al. 2009)– M87 (FERMI, Acciari et al. 2009)

• GRBs, energetics and spectra (Klebesadel et al. 1973)

• Doppler boosting in relativistic jets moving towards theobserver

• Light jets with relativistic spine and slower sheath layer– Spine produces synchrotron optical and X-ray photons, that are

boosted to GeV and TeV gamma rays by inverse Compton inthe sheath (e.g. Chiaberge et a. 2000, Tavecchio & Ghisellini2008)

– Radio emission from extended (expanding) cocoon

Relativistic radio jets

FR II FR I

! > 4 ! " .210 kpc

! > 10 ! " 21 kpc

! " 5100 pc

! " 3-201 pc

! " 20-30 ! " 10-200.1 pc

(Giovannini et al. 2005, Laing et al. 2008)

Jet Dissipation

• Clusters and groups of galaxies emit X-rays

• Thermal bremsstrahlung from hot (0.5 keV up to 10

keV) gas confined in potential well: hot Intra-Cluster

Medium (ICM)

• Heating mechanism?

• Evidence that AGN jets affect the ICM

• X-ray cavities corresponding to radio lobes

• Shells surrounding the cavities

• Shell temperature lower than the surrounding

medium: weak shocks

X-rayX-ray

Fabian et al. (2003, 2005)

Perseus cluster (CHANDRA)

Work done to produce

cavities (Allen et al. 2006,

Heinz et al. 2007):

!

Lkin

=1037L" ,radio core

7 #1022$

% &

'

( )

12 /17

W

age

kint

WLVPW =!

"=

1#

#

!""#$%&'()'*(+$,-

!"#$$%&'(#)!*%+,%%)!+-%!'..$%(#)!#)+#!/0!')1!+-%!2%+!34)%(.!5#,%$!67&&%)

!%+!'&8!9::;<!0%4)=!%+!'&8!9::><!/'&?'@%$1%

!%+!'&8!9::AB

!

1) PB = M•

B c2 , M

•

B ="G2#B MBH

2

cs3

2)Pj = 8.6 $1022L% , radio core12 /17 erg s&1,'% = 0

C'14#!DE4%+

High resolution photometry and

spectroscopy from HST

Compact rotating SMBH

The disk-jet paradigm

RMHD Jet LaunchingF!G,#!%)%$HI!$%J%$@#4$JK

!!!L%5&%$4')!14J3!'..$%(#)!6#(.(#/$01$#2)'B

!!!L%$$!*&'.3!-#&%!$'541!$#+'(#)!6#3(.()"4563((((73(.()8954"(((((:;(<()(<(;B

•!G,4J+%1!?'H)%(.!M%&1!%N+$'.+J

!!!$#+'(#)'&!%)%$HI!'+!'!$'+%

!!!?'4)&I!4)!+-%!O#$?!#O!P#I)()H!QEN

•!R'JJ!#ES&#,!$'+%

•!G-%!J5%.4M.!%)%$HI

!!!4J!+-%!?'N4?E?!5#JJ4*&%

!!!T#$%)+=!O'.+#$!#O!+-%!#ES&#,

•!U-4.-!4J!+-%!'JI?5+#(.!T#$%)+=

!!!O'.+#$!!!!!!!!!!!')1!+-%!'..%&%$'(#)

!!!%V.4%).I!W

Acceleration efficiency

•!7)'&I(.!J#&E(#)J!6%8H8!$%@4%,!LX)4H&!9:Y:B

•!R4.-%&!6YZ;ZBK!'..%&%$'(#)!'&#)H!'!?#)#5#&'$!M%&1!%JJ%)('&&I

!!!%)1J!'+!+-%!O'J+[?'H)%+#J#)4.!JE$O'.%!,4+-

!!!!!!!!!!!!!!!4)%V.4%)+!'..%&%$'(#)

•!\)!'!)#)[$%&'(@4J(.!Q#,!!+-%!34)%(.!%)%$HI!'+!+-%!O'J+!JE$O'.%

!!!4J!'&$%'1I!Y]^!#O!+-%!+#+'&!%)%$HI!'@'4&'*&%

!!!!!!!!!!!!!!!'..%&%$'(#)!4J!?#$%!%V.4%)+!4)!+-%!.&'JJ4.'&!$%H4?%!_

•!/#+-!')'&I(.'&!J%&O[J4?4&'$!?#1%&J!6T4<!"-4E%-<!/%H%&?')!YZZ9<

!!!`&'-'34J!a!L#)4H&!9::^<!9::bB!')1!)E?%$4.'&!J4?E&'(#)J

!!!6L#?4JJ'$#@!%+!'&8!9::><!9::Z<!G.-%3-#@J3#I!%+!'&8!9::ZB

!!!JEHH%J+!+-'+!+-%!'..%&%$'(#)!5$#.%JJ!.')!*%!?E.-

!!!?#$%!%V.4%)+<!,4+-!!!!!!!!!!!!!!!!!!!!!!!!!#$!%@%)!-4H-%$

c5%.4M.!%)%$HIK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!d!34)%(.!e!P#I)()H

Numerical Simulations

•!c5%.4'&!$%&'(@4J(.!R0fK!H$'@4+'(#)'&!%g%.+J

!!!)%H&%.+%1<!O#.EJ!#)!&'$H%!J.'&%!'..%&%$'(#)

•!\)4('&!')1!*#E)1'$I!.#)14(#)JK

!!![!$#+'()H!*#E)1'$I

!!!!!hJ#&41!$#+'+#$!6/0]icB!e!L%5&%$4')!14J3j

!![!5E$%&I!5#&#41'&!.E$$%)+[O$%%!?'H)%(.!M%&1

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!6/&')1O#$1!a!P'I)%!YZA9B

!![!5&'J?'!4)2%.+%1!,4+-!5#&#41'&!J5%%1

•!c4?E&'(#)!%@#&@%1!E5!+#!J+'(#)'$I!J+'+%

•!c+%'1I!J+'+%K!CR0f!'N4JI??%+$4.!4)@'$4')+J

7..%&%$'(#)!d!+$')JO%$!#O!P#I)()H!+#!34)%(.!QEN

Starting from “quasi-Keplerian” disk in equilibrium with gravity, thermal pressure gradient and

Lorentz force search for stationary states

Alpha prescription for momentum transport

Disk parameters: µ = B2/2P = 0.6

! = cs /VK = 0.1

H = ! r

"m = #m vA H exp[-2(z/H)2]

Cases: a) #m = 0.1 $m = 1 poloidal/toroidal

b) #m = 1 $m = 1

c) #m = 1 $m = 3

d) #m = 0.1 $m = 1 low resolution

2.5 D MHD

Codes

FLASH2.5

& PLUTO

with AMR

7 levels of

refinement

0 R equatorial plane 40

0 Z

Sym

metr

y a

xis

12

0

Open B

oundary

Open Boundary

Sink region

0 1

0 0

.5

Jet Acceleration

7&O@%)!JE$O'.%

T4H-+!JE$O'.%

kR!!JE$O'.%

T#$%)+=!l'??'

kR

P#I)()H

7&O@%) kR

7&#)H!'!?'H)%(.!JE$O'.%!,4+-!$:!d!Y

T#$%)+=!O#$.%

"%)+$4OEH'&

G#+'&

•!k&#,!!'..%&%$'+%J!%@%)

!!*%I#)1!kR!JE$O'.%!E5!+#

!!!!!!!!!!!!!!!,4+-!')!%V.4%).I

•!k&#,!4J!J(&&!'..%&%$'()H_

!!6)%%1!&'$H%$!J4?E&'(#)JB

•!k&#,!'..%&%$'+%1!*I

!!T#$%)+=!O#$.%J

!!6!!!!!!!5$%JJE$%B!!')1

!!.%)+$4OEH'&!%g%.+J

•!/%I#)1!kR!JE$O'.%

!!?'H)%(.!5$%JJE$%

!!1$4@%J!+-%!Q#,

!!6?'H)%(.!)#==&%<

!!T4!%+!'&8!YZZ9B

Jets, winds and (de)collimation

Initial

Final

Collimation

(Jet)

Decollimation

(Wind)

FMag FMag

• The magnetic force associated with the toroidal field (perpendicular to the

isosurfaces) tends to collimate the inner field lines and to decollimate the outer ones, creating a

configuration favorable for efficient acceleration.

• The structure suggests a fast jet (collimated) – slower wind (decollimated) configuration.

• In the relativistic regime, the electric force is comparable to the magnetic but with opposite sign:

differential collimation and acceleration are still possible but on very long spatial scales.

• Focus: magnetization

• Resistive 2.5D MHD simulations of

jet launching:

Tzeferacos et al. MNRAS 2009

! = 2P / B2

• Self-consistent jet ejection from

accretion disc

• Super Alfvènic, super fast

magneto-sonic outflows

• Steady state solutions obtained

only above equipartition plasma

! (case 1,2)

• From weak (case 1, 2) to strong

magnetic fields (case 3, 4)

1/3 ! " ! 10.0

• Strong correlation between

disk heating effects and

mass loading.

• Efficient acceleration and

stationarity is found for

mildly warm and cold

cases, comparable to slow

radio-galaxies and YSO jets

• Focus: entropy generation

due to viscous and Ohmic

heating

• Viscous and resistive 2.5D

MHD simulations of jet

launching

• # prescription for viscosity

and resistivity, with magnetic

Prandtl number:

Tzeferacos et al. (2011)

7&5-'!')1!14J3!')1!14J3!5-IJ4.'&5-IJ4.'&

5'$'?%+%$J5'$'?%+%$JWW

iE?%$4.'&!J4?E&'(#)J!#O!RC\

mg%.+J!#O!+-%!)E?%$4.JW

=>)11$'?2'?(=>)11$'?2'?(,>$,>$(())10>)(0#$-"#20%&'10>)(0#$-"#20%&'

2

2 !"

#$%

&'

= H

z

sHec()

R#?%)+E?!+$')J5#$+

`4J.#J4+I!#O!n[14J3JK

^f!-4H-[$%J#&E(#)!J4?E&'(#)

4)!J-%'$4)H!*#N!'55$#N4?'(#)

6c')#!a!\)E+JE3'!9::Y<!R4H)#)%!%+!'&!9::ZB

\)!'!.'$+%J4')!O$'?%!#O!$%O%$%).%!.#$#+'()H

,4+-!+-%!14J3

G-%!.-'))%&!J#&E(#)<!4)+%$?4o%)+!J+'+%J<

+$')J4(#)!+#!+E$*E&%).%<!.'&.E&'(#)!#O

R'N,%&&!J+$%JJ%J<!'J5%.+!$'(#!1%5%)1%).%

fI)'?#

R'N,%&&!J+$%JJ%J!')1!'&5-'

p)J+$'(M%1!J-%'$4)H!*#N%J!-'@%!*%%)

J-#,)!+#!JEg%$!O$#?!?')I!5$#*&%?J

6k$#?')H!%+!'&8!9::><!C%H%@!a!p?-E$')!9::A<!

/#1#!%+!'&8!9::A<!9:Y:B

\)!5'$(.E&'$!,4+-!=%$#!?%')

M%&1!+-%!+$')J5#$+!*%.#?%J!

)%H&4H4*&%!'+!-4H-!C%I)#&1J!

)E?*%$JK!'$(O'.+!#O!J-%'$4)H!*#N

G#,'$1J!H&#*'&!J4?E&'(#)J

Maxwell stressesa.r. 4

P$%&4?4)'$I!$%JE&+J!O$#?!J4?E&'(#)J!4)!,-4.-!H$'@4+'(#)'&!J+$'(M.'(#)!4J!4).&E1%1

c(&&!J-%'$4)H!*#N!.#)14(#)J!4)!+-%!$'14'&!14$%.(#)8!k4$J+!J+%5!+#,'$1J!H&#*'&!J4?E&'(#)J8

f#?'4)!J4=%!^0Nb0N;0!60!1%)J4+I!J.'&%!-%4H-+B8!9::!5#4)+J!5%$!J.'&%!-%4H-+8!

GE$*E&%)+!$%H4#)!4)!+-%!1%)J%$!$%H4#)!4)!+-%!?411&%

\)+%$%J()H!5#4)+K!5%$4#14.!O#$?'(#)!#O!-4H-&I!?'H)%(=%1!$%H4#)J!4)!+-%!E55%$!')1!&#,%$

$%H4#)J!6?'H)%(=%1!.#$#)'%B

7=4?E+-'&!

"#?5#)%)+

#O!+-%!?'H)%(.

!M%&18

!N[=!.E+

Relativistic Jet Propagation

• Are jets stable ?

• Do they dissipate magnetic flux ?

• Intrinsic/external instabilities

• How do jets decelerate without decollimating ?

• Mass entrainment from the ambient medium across

an unstable boundary layer! “internal” entrainment: diffusion of mass lost from stars

within the jet volume (Komissarov 1994)

! “external entrainment: ingestion of ambient gas from the

surrounding IGM via a turbulent unstable boundary layer

(Begelman 1982; De Young 1996)

• Connecting morphologies with dynamics

• Instabilities and turbulent particle acceleration

Interaction with external medium

• Shear instabilities in supersonic flows(Brown & Roshko 1974)

• Relativistic Kelvin-Helmholtz instabilities in

astrophysical jets (Ferrari et al. 1978, Hardee 1987, etc.)

• Stabilized by extended shear layers and longitudinal

magnetic fields; nonlinear saturation effects (Benford et

al. 1980)

! Solve the full set of inviscid relativistic hydro equations in 3D:

! Computational domain:

! Cartesian coordinates, homogeneous external medium, pressure

matched jet

! Perturbations at the jet inlet: pinching, helical, fluting%b = %b (1+!) & ! ' 0.05

! Relativistic Mach numberMr = %bvb/%svs

! Synge EoS

3D Relativistic Hydro Jets

outflow

outflow

outflowJet Inlet

+

perturbations yx

z

Mixing by Shear Instabilities

% = 10, M = 3, " = 102

% = 10, M = 3, " = 104

" Relativistic spine

surrounded by a turbulent

mixing layer

% = 10, M = 30, " = 102

A

B

E

Passive scalar

Comparison with observationsemissivity integration along the line of sight

at different projection angles

Agreement with Bridle & Laing empirical models

Intrinsic instabilities

• Current-driven kink instabilities related to a toroidalmagnetic field component in current carrying jets (Bateman1978, Appl et al. 2000, Giannios & Spruit 2006, Narayan et al. 2009)

• Stabilized by extended shears (Mizuno et al. 2007), jetexpansion (Moll et al. 2008, McKinney & Blandford 2009)

• Detailed nonlinear analysis required to test instabilityeffect on morphologies and radiation

Magnetized Jets

! M = Mach Number; " = (amb/(jet; % = Lorentz factor

! ) = Magnetization

!Poloidal model: uniform Bz

!Toroidal model:

! # = Rotation

!

B" =Bm

(r /a) for r < a

Bm

(a /r) for r > a

# $ %

!

"# =B#

2/$2

2 pg"z =

Bz

2

2 pg

!

v" (r) =#B" (r)

Bm

@A$",-(&B(C)?'$%"(D$1*-

! Toroidal models shows considerable deflection

! " intrinsic 3D effect

Axisym (“2.5” D) 3D LoRes 3D HiRes

RHD

(Hydro) RMHD

Poloidal RMHD

Toroidal

Pressure distribution

Magnetic Field Topology

Perturbation modes

! Hydro case and poloidal case:

prevailing of short KH wavelength

modes (Massaglia et al. ‘96,

Hardee ‘87)

! Toroidal case show suppression

of surface modes, kink modes

prevail

hydroPoloidal

Tor (HiRes)

Kinetic to Poynting flux ratio

• Initial radial equilibrium structure:

• Relativistic jets at the inlet % = 10

• Stratification " = (amb/(jet = 104 * 102

!

dp

dr"w# 2v$

2

r= % &E( )E + J 'B

Er = " v 'B( )r

= " vzB$ " v$Bz( )

J 'B( )r

= " Bz

dBz

dr+B$

r

d

drrB$( )

(

) *

+

, -

"dp

dr+w# 2v$

2

r=1

r2

d

dr

rB$( )2

2"rEr( )

2

2

(

)

* *

+

,

- -

+1

2

dBz

2

dr

" !"#$%

" !"#$&

J+$'(M.'(#)

'(

)

*+

,

iq!U4HH&4)H

/!,%'3

U4HH&4)H

/!J+$#)H

Fluxes A B C D* E F

Fk/FP 3.5 1 70 1000 3.5 1

Rotation 0 0 0 0 1 1

rP#&#41'&!M%&1

time

distance

ss s> ;: ;s

()-*",

t%+!.%)+%$[#O[?'JJ!5#J4(#)

• Large Poynting fluxes produce strong kinks, the head

of the flow becomes contorted

• Large kinetic fluxes avoid kinks, the heads of the jet

proceeds at large velocity

• The spine of the jet is always highly relativistic on the

average, shocks create intermittent structures

• When the jet encounters the low density region its

structure becomes again straight and kinks

disappear: hints of outflow acceleration ?

Experiment on supersonic (but not

relativistic) hydro jets (Torino, Milano)

Heavy Jet

Light jet

Conclusions• Relativistic jets show a nonlinear evolution that is different from non

relativistic jets in many aspects (AGN vs star)

• Acceleration of relativistic jets in the magneto-centrifugal scheme

extends beyond the fast-alfvenic point and is strictly correlated with the

collimation process

• Relativistic hydro jets are subject to strong mass entrainment by shear

instabilities and form naturally the spine/sheath layer structure

• Relativistic magnetized jets with strong toroidal component are subject

to kink instability that may disappear when they emerge from the

denser regions

• Entrainment and instabilities do not slow down the spine of the jet that

remains relativistic up to the hot spot/termination shock

• The issue of jet acceleration/deceleration requires further analysis of

dissipation and turbulent processes

• Particle acceleration: beyond MHD, PIC simulations

• Validation of codes on laboratory experiments is fundamental