Chaire Galaxies et Cosmologie

Galaxies with radio and optical jets

Françoise Combes

The jet: component of the standard modelLess than 10% of galaxies have an active nucleus. 10% of AGN haveRadio jets (« Radio-Loud »)Every galaxy has a black holebut the activity time-scale isshort, ~ 10-40 million yrs

According to the angle of the line of sight: the jet is seen, or relativisticg j ,motions, broad lines exist, or arehidden by the molecular torus( 2 i l i i )(type 2, scattering, polarisation)

2

Distinction between jet and windThe wind comes from the heated disk, which can,evaporateOr the magnetic pressure

jet wind is too strong

Turbulence in the disk

jet wind

Turbulence in the diskMRI instability

starBH

disk

magnetic lines

3

Activity cycles

Separation of lobes ~ 100 kpc,

V ~ 1000 km/s

age t ~ 108 yrs

Several cycles?

Other way to estimate the duration of the activity cycles of AGN t ~ (galaxy life)(% active time)

10 8

4

~ (1010 yrs)(1% of galaxies active with jets) ~ 108 yrs

Two types of morphologies for the radio jetsFR II (left) & FR I (right) High luminosity

3C 219

3C 31Low luminosity

3C 33.1 3C 313C 296

3C 47

Hot spots in the centerHot spots at

3C 465the end

5

Why only one jet?3C133Image VLAImage VLA

Faraday depolarisation~2

3C133Polarisation The visible jet is alwaysPolarisation j y

towards the observer

Eliminated hypothesis--The jet is alternatively on oneside or the other

6

side or the other--Absorbing mediumLaing, 1988

Relativistic aberration, Doppler boostReference frame of the fluidIsotropic emission

Reference frame of observerLorentz transformation

Isotropic emission

Already aberration at small speed (ex. rain) -- For AGN ~5

7Flux multiplied by D2

Total relativistic Doppler effectDoppler factor ~5 v/c ~ 0.98, D ~ 9.9

Aberration, Flux multiplied by D2

Effect of time dilatation, Flux multiplied by D , p y

Time 1Time 2 Source at rest STime 3

Source in

S

Time 1 Source in motion

Time 2Time 3

Doppler effect on frequencies, Flux in (synchrotron = 1)Flux multiplied by D3+ ~D4 ~ 9600

8

Some up to 100, D~200, and D4 ~ 16 108 !!

Optical jets, various wavelengths

Martel et al 2003

Superposition with Radio

Jet radio: contoursJet radio: contours// optical jet (HST)

67kpc long

HST+Merlin 10

HST ChandraMerlin

3C273 the most nearby quasar3C273, the most nearby quasarJet detected at allwavelengthsg

Superposition of optical jet(HST) in X-rays (Chandra)and in radio cm (Merlin) 11

12

Jets can be super-luminalP at velocity v, with respect to Oy = r sin t = r/v

Light coming from P reaches us in less time than light

C27

9

coming from O.Time observed for the object to go from O to Pdans

3C

from O to P tapp = t - x/ctapp = (r/v) - (r/c) cos t = (r/v) (1 cos )et

radi

o

tapp = (r/v) (1 - cos )V apparent on the sky

vapp = y/tapp

J

app y appvapp = (v sin )/(1 - cos )

For v << c =v/c ~0 v = v sin

To observer

For v << c, =v/c 0 vapp = v sinFor v ~ c, vapp >> v and even larger than c

Relativistic jets: a large range of scalesHigh resolution Space Telescope+ radio jet (VLA)

14

Black hole in rotation: origin of Radio jets?

If the black hole is rotating, energy can be extracted from it,by the Penrose process 15

PenrosePenrose processprocess

E2 > E1

up to 29%E<0

p %

E1

Jean-Pierre Luminet16

E1

Mechanism of Blandford-ZnajekThe goal is to extract energy and angular momentum from the black holein rotation. The electromagnetic field around the hole is perturbedby magneto spherical currents which produce a torqueby magneto-spherical currents, which produce a torque Slow down the black hole

Poloidal B field, and B same senseDescribed by the potential

Pair creatione+ - e-

Described by the potentialvector A

H HorizonParticules in T can onlyfall in the hole

disk

The positrons are quicklyabsorbed by the hole,The atmosphere is of

17

negative charge

Blandford-Znajek (following)

disk

18Poynting vector S= E x B /

Electromagnetic extraction of rotational energy

horizonhorizon

ergospherePlasma dominated

S

ergosphereby magnetic energy

B

SS

Flux of Poyntingvector B

S

Blandford and Znajek 1977Equatorial plane B

19

Extraction MHD and not only MD

horizonSPlasma dominated horizon

ergospherev

Plasma dominatedby magnetic energy

ergosphere

BS

v

v

Flux of vectorof Poynting

SS

v

vy g

B

Region dominatedby particules

v

Negative flux of particules

v

Punsly & Coroniti 1990

BSof particulesEquatorial plane

20

Torque slowing down the black hole: Jx BTorque slowing down the black hole: Jx B

Meridian plane

21Angular momentum L Punsly & Coroniti 1990

Numerical simulations: MD & MHD

Monopole field (Komissarov 2001, McKinney 2005)

H

a=0.1•Le flux of Poyntingcorresponds to model

a=0.9

corresponds to modelof Blandford-Znajekstationnary state

Z

a=0.5y

L t f t 0t=120

i il

Lorentz factor

RZ

0

MHD very similarto MD modelThe energy is extracted from

BH, the introduction of particulesMHD d t h th

a=0.9 from 0 to 14

MHD does not change thephenomenon MD

R 22

Ergosphere and B field in simulations

Simulations MD, uniform field (Komissarov 2004)

B2 – D2 h All field lines entering theErgosphere are in rotation

horizon

g pup to 0.5 times of hole

ergosphere The dissipative layer in the equatorial plane is the sourceof energyof energy

Dissipative layer

The energie is extracted from the region betweenThe energie is extracted from the region between horizon and ergosphere (=processus of Penrose)

23

Jets are confined by magnetic fieldsJets are confined by magnetic fields

Collimationover 8 ordersover 8 ordersof magnitudein scales

24

MHD and jet confinementMHD and jet confinement

The differential rotationtwists the field lineswhich slows down rotationand allows more accretion

Magnetic pressure andthermal pressurethermal pressure accelerate the jet

Uchida et al 1999Magnetic tension collimates

25

Ejection mechanisms

Magnetic A black hole in rotation (a~1) accretes ionized and magnetized gas

field lines

Ergosphere

The gas falls in the hole, and someElectromagnetic energy is ejected along the rotation a is Ergosphere

Black hole

rotation axisThis energy flux (Poynting) will be chargedwith particules, to form a relativistic jet Black holewith particules, to form a relativistic jetSimilarity with the processus of Blandford-Znajek

The reaction of the magnetic fieldis to accelerate the plasmain counter rotation of the holein counter-rotation of the hole

26Koide et al 2002

Arrival of L < 0

The radio galaxies are in general Ellipticals, may b b M Mbe because MBH ~Mbulbe

NGC 4261NGC 7052

Galaxies host Cen A

of FR-Is and FR-IIs

The radio galaxies FR I and FR II areGiant ellipticalswith dust laneswith dust lanes

The FRI are often cD galaxies at the center of rich clusters

M87

28

The majority of quasars are observed in galaxy mergers galaxy mergers

Violent gas shocks fueling of the black hole

Ejection of plasma: radio lobesin ellipticals results of merersin ellipticals, results of merers

Cygnus A Image radio, VLA

Optical mage , HST 30

A double quasar, just merging: 3C75, z=0.023Image radio, VLA

O i l i HSTOptical image HST

25,000 ly

31

Radio lobes, galaxies in motionGalaxies move at a velocity up to1000k / i l l

3C1291000km/s in galaxy clusters

3C4653C465

32

How two radio lobes canHow two radio lobes canmerge in a signle one

NGC 1265,Perseus cluster

33

Weaker radio sources: more diffuse lobes

NGC 1316Radio, VLA

NGC 1316

in Fornaxin Fornax

HST

Origin of radio mission :P l t d i ith f ( l 0 t l• Power-law spectrum decreasing with frequency (slope 0 at nucleus,

then -1)• linearly polarised emission (at least 30% which is a lot) linearly polarised emission (at least 30%, which is a lot)

Synchrotron radiation emitted by electrons in relativistic motion in a magnetic fieldF l t f

11 γavec γ 2

22cv

ecmE For an electron of energy

Hzγ1024 26 B

The characteristic frequency of emissionis

Hz γ102.4~ Bc

With B in Gauss

35

Emission gamma (TeV) from a blazarVery high energy photons are emitted by radio AGN, when their jet isoriented towards the observer blazar & « Flat Spectrum Radio Quasar » (FSRQ) Doppler factors of 20-50!

36Marscher 2005

Jets in Gamma: high variability

Radiation mechanisms:Radiation mechanisms: synchrotron, SSC(synchrotron self-Compton)( y p )& EIC (external inverseCompton)At low power: SSCAt low power: SSCAt high power: EIC

Variability on time scales down to minutesdown to minutes

37

The blazar sequence

The highest luminosityblazars have the softestblazars have the softestspectra

Electrons of high energyIn low power objects“injection” betweenmin =104-5 to 106-7

At high L is smallerAt high L, min is smaller

38

Mechanisms of photons in culture

B-field

3. Compton 2. Pair3. Compton scattering

pscattering

5 Compton

production

1 Seed high 5. Compton scattering4. Pair

production

1. Seed high-energy photon

Multiplication of high energy rays, as soon as(1) high energy photons are injected(2) there exists a B field transverse or chaotic(3) an isotropic radiation field (BLR at 1017 cm)

39

( ) p ( )(4) the Lorentz factor of the jet ~4-10Stern & Poutanen (2006, 2008)

Why some AGN have radio jetsy jand not others?

Frequency and circumstances: Most AGN have no jet,90% are « Radio-Quiet »

10% of « Radio-Loud »: a true dichotomie

Are these different phases of anuniversal evolution?universal evolution?

Centaurus ABlue: X-rays

40

Blue: X-rays Red: Radio

Kellerman 1989R=Radio/Optical

Two sequences in the plane L LTwo sequences in the plane LB–LR

41

Same sequences in (LB/LEdd)-(LR/LEdd)This time normalised to LEdd ≈ 1038 × (MBH/M⊙) erg/s

42

R~ L /L accretion rate ~ L /LR~ LR/LB, accretion rate ~ Lacc/LEdd

43

Criteria for radio jetsCriteria for radio jets

1) Th R i h h i1) The parameter R increases when the accretionrate Lacc/LEdd decreases

2) This is verified for both sequences « radio-loud » d di iand « radio-quiet »

3) A saturation of the parameter R occurs at lowaccretion rate λ < 10-3

44

Dependence of R on the mass of the BH

For powerful radio jets, MBH must be > 108M⊙45

The micro-quasars in our Galaxy: nearby, variable athuman time-scalehuman time scale

SS433: micro-quasar

Objects of stellar massesThe end of life for massive starsThe end of life for massive starsRotation of the BH 1000 timesper second

46

Microquasars & Quasars

47

Micro-quasar GRS 1915

superluminalsuperluminalvelocity Scale: one monthy

X-Rays: redGamma-rays: grennRadio : blue

Ejection cycles ofEjection cycles ofabout one hour

A dizain per day48

Radio versus X for micro-quasarsSradio

SXSX

For low accretion rates, the radio luminosity increases with the accretion rate (LX) like LR∝LX

0.7 (Gallo et al. 2003)But for higher accretion rates ≥ 0 01 Edd the jet productionBut for higher accretion rates ≥ 0.01 Edd , the jet production becomes intermittent (Fender et al., 2004) 49

The accretion phases vary forThe accretion phases vary forexample Cyg X-1

Accretion High (H)(small truncation

di )

H L

radius)Accretion low (L)(higher truncation(higher truncationradius)TransitionsEnergy emittedin photons Compton

50

The different phasesFender 1999 Micro-quasars & AGN

The hard X are correlated withThe hard X are correlated withthe radio emission

InstableIntermittent

1.0?In the high luminosity phase, the disk radiates efficiently,

d l t t itt d

Intermittent

and electrons are not emitted

In the low phase, ADAFDi i In the low phase, ADAFTruncation of the disk, formation of a corona where photons are

Disque mincePas de jet nide couronne

comptonized(hard X-rays)Disque tronqué

C

51The corona is the jet baseCouronneet jet continu0.1?

Several phases for the SeyfertSeveral phases for the SeyfertSeyferts 1 in general accrete at the Eddington limit

– this corresponds to a high accretion rate, unstable -- oscillation time-scale of ~ 2 yr (M/106 M)

Some Seyfert galaxies have no longer broad lines “Narrow Line S1” example NLS1 PKS 2004-447p

– M = 5 106 M; could become a classical S 1 in < 10 yr– A brighter AGN , broader lines

52

b g te GN , b oade es

Criteria for radio jetsCriteria for radio jets

For AGNs as for micro-quasars, LR and Lacc are related for the low accretion rates, and for high accretion rates, the production of jets become intermittent (e g Merloni et al 2003 Nipoti et aljets become intermittent (e.g., Merloni et al., 2003, Nipoti et al., 2005)

But the relations are verified separately for spirals and ellipticals, as for two parallel relations

there exists an other parameter, related to the formation of these galaxies, and of their central black holegThe spin of the black hole?

53

The role of the black hole spinpIf jets are produced by the extraction of the rotational energy of

black holes and if elliptical galaxies have more luminous radioblack holes and if elliptical galaxies have more luminous radio jets

-- does this mean that ellipticals have not enough gas to stop the jets?

-- or ellipticals have higher spin parameters (a)?

Ellipticals are formed by mergers of smaller galaxies, but more frequently by major mergers

A large number of minor mergers could arrive in the same finalA large number of minor mergers could arrive in the same final mass state, but the spin would be cancelled statistically

54

Minor & major mergersMinor & major mergers

id l i i dA residual spin is expectedfor the black hole resultingfrom a major merger

The final angular momentumcoming from several BH

55

from a major mergerof random orientation cancels out

Simulations ofjet formationjet formation

kBrinkmann& CamenzindLSW 2004

Brinkmann &Camenzind 2004

LSW 2004

56

Esin et al. 1995A. Müller (2004) 57

Unstable: Oscillations

sity

Lum

inos

Fender & Belloni 2004 ARAA 58Frequency

ConclusionsProperties of jets-- relativistic boost, disymmetry, y y-- superluminal jets-- analogy with micro-quasars-- The radio power is 3 orders of magnitude largerin ellipticals relative to spirals

How are jets formed?-- Extraction of the rotational energy of the BH (Blandford-Znajek)gy ( j )(processus of Penrose + B field)

h di i h h i d-- the radio power increases when the accretion rate decreasesEllipticals have black holes with a larger spin ( a~1)Could be due to their formation in major mergers

59

Could be due to their formation in major mergers