Matteo Guainazzi European Space Astronomy Center of ESA Villafranca del Castillo (Spain)

Science Operations & Data Systems Division Research & Scientific Support Department

Page 1

XMM-NewtonXMM-Newton

“Did I say radio quiet?”Radio-loudness in radio-quiet

Seyferts [and a note on X-ray core spectra in low-power

radio RGs]

Matteo GuainazziEuropean Space Astronomy Center of ESA

Villafranca del Castillo (Spain)

Matteo Guainazzi - “Did I say radio-quiet?” – Radio Galaxies in the Chandra era (Cambridge, U.S.A.), 10/7/2008

AGN SEDAGN SED

(Elv

is e

t al.

1994

)


Gallery of radio emission in Gallery of radio emission in SeyfertsSeyferts

Unresolved Sub-pc scale

0.1 pc

NGC4395

pc-scale, sub-relativistic

Mkn231(V

LB

A, A

nder

son

et a

l. 20

04)

(VL

BI,

Wro

bel &

Ho

2006

)

(VL

BA

, Ulv

esta

d et

al.

1999

)

kpc-scale (44% of 43 CfA galaxies – AGN driven)

(VL

A, G

allim

ore

et a

l. 20

06)


OutlineOutline

Radio emission in Seyfert galaxies: core and jet Radio emission in Seyfert galaxies: core and jet emissionemission

Jet-ISM interaction and the ionization Jet-ISM interaction and the ionization mechanism of the [E]NLRmechanism of the [E]NLR

Lessons and questions on Radio Galaxies core Lessons and questions on Radio Galaxies core X-ray spectra from Seyfert Galaxies X-ray X-ray spectra from Seyfert Galaxies X-ray spectraspectra


OutlineOutline

Radio emission in Seyfert galaxies: core and Radio emission in Seyfert galaxies: core and jet emissionjet emission


Lessons and questions on RG core X-ray Lessons and questions on RG core X-ray spectra from Seyfert Galaxies X-ray spectraspectra from Seyfert Galaxies X-ray spectra


Multiple scales in individual objectsMultiple scales in individual objects

1 kpc

1.5 kpc

7.5 kpc

Multiple kpc-components in Mkn 6

(Kharb et al. 2004)

From pc- to kpc-scale in Mkn 231

(Ulvestad et al. 1999)

NGC1068

Internal shock in a jet?

Free-free absorbed, variableIonized cocoon?

Resolved ∟ radio axisFree-free thermal emission from the inner side of the maser disk

Combination of:• compact flat-spectrum• extended steep-spectrum

(Gal

limor

e et

al.

2004

)


Radio-quiet/-loud dichotomoyRadio-quiet/-loud dichotomoy

Is the radio-loudness (R) distribution bi-modal?

YES: Strittmatter et al. (1980), Kellermann et al. (1989), Wadadekar & Kembhhavi (1999),

Ivezic et al. (2002), Panessa et al. (2007)

NO: White et al. (2000), Hewett et al. (2001), Cirasuolo et al. (2003)

Possible alternative R definitions:• Relative Lradioradio/LFIR (Rush et al. 1996, Thean et al. 2000)

• IRAS severely contaminated by the host galaxy

• Relative Lradioradio/LX (Terashima & Wilson 2003)

• Good for highly obscured and LLAGN

• Absolute radio power (Miller et al. 1990)

• Radio-loudness should be w.r.t. other λλ

Seyferts nuclei are not radio-quiet![60% have R>10, for:R≡Lν(6 cm)/ Lν(B)]

(Ho & Peng 2001)


Spectral indicesSpectral indices(Thean et al. 2001)

(Ulvestad & Ho et al. 2001)

Palomar Seyferts have a largefraction of flat spectra (α≥-0.7)

• No optically-thin synchrotron emission• Synchrotron self-absorption?• Free-free emission?• Free-free absorption?• Radiative inefficient accretion?• Link with Giga-Hertz Peaked Sources?

• Spectral turnover• Sub-relativistic jets


Radio-power dependenceRadio-power dependence

3 Low-luminosity AGN: α = -0.3-0.1

(Ulv

esta

d &

Ho

et a

l. 20

01)

(Doi et al. 2005)

• Pure ADAF models over-predicts the X-ray emission by ≥10 (Yi & Boughn 1998, Quataert et al. 2001)

• → Co-presence of an ADAF and a compact jet• Weaker sources have weaker jets → ADAF emission starts become visible at low radio L


Radio-loudness vs. accretion rateRadio-loudness vs. accretion rate(Panessa et al. 2007)

(Greene & Ho 2006)

State transition at Lbol/LEdd≈0.01:• Below this value: radiatively inefficient accretion flow + outflow• Above this value: optically-thick, geometrically-thin disk, radiation pressure dominated slim disk


Is there a X-ray/radio correlation?Is there a X-ray/radio correlation?

YES: Panessa et al. (2007)

NO (distance effect in flux-limited samples): Bianchi et al. (2008)


Fundamental plane of BH activityFundamental plane of BH activity

(Mer

loni

et a

l. 20

03, 2

006;

Fal

cke

et a

l. 20

04)

• Scale-invariant jets [Heinz & Sunyaev 2003]• Radio luminosity scales with BH mass and accretion rate, independently of the jet model• Scaling depends on α, and the electron distribution index → on accretion physics only

• X-ray emission from BH accretion at a few percent Eddington is consistent with radiative inefficient flow only

• In low accretion rate sources, jet power is proportional to accretion power

• Challenges? Seyferts and LL RGs seem to follow different planes [Wang et al. 2006; Panessa et al. 2007]


Jet/ISM interactionsJet/ISM interactions

IIIZw2

43 GHz(jet hotspots)

15 GHz(external shell)

(Bru

nthh

aler

et a

l. 20

05) NGC3079

[Earlier results: Wilson & Ulvestad 1982, Oosterloo et al. 2000)]

“Slower-when-brighter” behaviour(Saxton et al. 2005)

Interaction with clumpy ISM could “frustrate” the jet in Seyfert galaxiesAlternative: continuous emission of

“aborted jets” (Ghisellini et al. 2004)

(Mid

delb

erg

et a

l. 20

08)


OutlineOutline





Radio/NLR interactionRadio/NLR interactionCorrelation between radio and optical power (de Bruyn & Wilson 1978, Wilson & Willis 1980, Heckman et al. 1981, Meurs & Wilson 1984, Whittle 1985, Wilson 1991, Whittle 1992)

(Ho

& P

eng

2001

)

Correlation between radio and line width (Wilson & Willis 1980, Whittle 1985, 1992)

(Ulv

esta

d &

Ho

2001

)

Jet vs. NLR power(Nagar et al. 2005)

In LLAGN the jet is the primaryoutput channel of accretionenergy


Do radio jets affect NLR …Do radio jets affect NLR …

(Capetti et al. 1998)

(Axon et al. 1998)

Morphology?

Kinematics?(Yes, but see Das et al. 2006

for a counter-example on NGC1068)

(Capetti et al. 1996)

Ionization? position of radio knot

Contours: radioGrayscale: O[III]

Contours: radioGrayscale: O[III]


Role of shock ionizationRole of shock ionization(ESO428-G14; Riffel et al. 2006)

[Fe II] [O III] 2cm

<80-90%

<70-80%

Chandra(NGC2110; Evans et al. 2006)

Contribution to ionization by

shocks


Shock ionizationShock ionization

Ionizing shock model:• Could explain extended soft X-ray emission in obscured AGN (Wilson & Raymond 1999)• Would require a jet dominated by thermal plasma [Bicknell 2002] where radio emission is just a tracer of the underlying flow• “ACIS measurements will be crucial to test it”

(Dop

ita 1

995;

Dop

ita &

Sut

herl

and

1995

)

(Wilson &

Raym

ond 1999)


Soft X-ray extended emission and NLRSoft X-ray extended emission and NLR

Circinus Galaxy(Smith & Wilson 2001)

NGC4151(Yang et al. 2001)

NGC1386(Bianchi et al. 2006)



600 pc 600 pc 500 pc 600 pc

500 pc700 pc

1000 pc

2000 pc

Images: O[III] – Contours: soft X-rays

NGC1068(Young et al. 2001)


Mkn3(Sako et al. 2000)


Seyfert soft X-ray spectraSeyfert soft X-ray spectra

NGC1068/RGS

High-resolution soft X-ray spectra are dominated by AGN photoionization

Contribution by thermal plasma negligible (Brinkman et al. 2002, Bianchi et al. 2006)

(Sambruna et al. 2001)

(Kinkhabwala et al. 2002; Gallimore et al. 2004)

(Sako et al. 2000)

(Guainazzi & Bianchi 2007)

Narrow (<10 eV) Radiative Recombination Continua in a sample of Seyfert 2 galaxies with the RGS


OutlineOutline





X-ray core emission of low-L RGsX-ray core emission of low-L RGs

FRI [Donato et al. 2004; Evans et al. 2006]

– Unobscured, Г=1.88±0.02– Correlation between X-ray, radio, optical → origin at the base of

the relativistically beamed radio jet

FRII [Evans et al. 2006]

– Obscured (NH>1023 cm-2), Г=1.76±0.02, Fe Kα line

– Torus-surrounded accretion disk emission– Soft excess → jet-related origin

BLRG [Grandi et al. 2004, 2006, 2007]:

– Unobscured, disk-dominated emission (beamed contamination ≤70%)

– Weak Fe Kα line, weak Compton-reflection

Anticorrelation between Fe Kα EW and R in heterogeneous radio-loud samples [Reeves & Turner 2000, Grandi et al. 2007]


Seyfert X-ray emissionSeyfert X-ray emission

(Courtesy of I.George)

Seyfert 2s

Unobscured Seyfert 2s

Seyfert 1-1.5s

There is nothing like a “power-law” X-ray spectrum in Seyfert Galaxies

(Malizia et al. 1997)

Disk(how?)

Disk outflowTorus + disk

Torus + disk

Disk corona

(1021 cm-2)


Open questionsOpen questions

If we see the accretion disk in the X-ray spectra of RGs– Where are the relativistically smeared features?– Is there any Compton reflection?

– BeppoSAX: weak (Grandi et al. 2006)

– Where is the warm absorber?– Are warm absorber outflows and radio jets two different

manifestations of the same underlying medium?– Why there is no soft excess in FRI?– Which is the true nature of the soft excess in FRIIs?– Is the distribution of absorbing column densities consistent

between RGs and Seyferts?

(Evans et al. 2006)

RG Seyfert

(Tüller et al. 2008)


Soft excess in FRIIs: 3C344Soft excess in FRIIs: 3C344

pn3C445

26 Starburst(after Wu et al. 2002)

Maximum jet contribution in the

soft X-ray band

(Sambruna et al. 2007; Grandi et al. 2007)

Sy2s

(Guainazzi 2008)

• Soft X-ray emission lines in both the XMM-Newton EPIC and RGS shows that the soft X-ray emission is dominated by AGN-photoionized gas• This constraints the contribution of any jet-related non-thermal emission• These measurements are challenging, but possible. Similar example: 3C33 (Torresi et al., in prep.)


Specific Specific Chandra Chandra contributionscontributions

Spatial resolution required to resolve the nuclear emission

Spatially resolved low-resolution spectroscopy (coupled with high-throughput, serendipitous high-resolution spectroscopy with the XMM-Newton RGS) is key to understand the nature of the emission on 0.1-1 kpc scale → ionization mechanism of the [E]NLR

My pledge for the future:– Completeness! (see, e.g., Massaro’s talk)


ConclusionsConclusions

At least 50% of Seyfert galaxies are radio emitters on different scales (from sub-pc to kpc-scale)

Core radio emission probably due to a combonation of jet and low-efficiency accretion (the latter more important for weak sources)

Interaction with (clumpy?) ISM frustrates sub-relativistic jets in radio-quiet AGN

Fundamental plane indicative of scale-invariant jet physics

Combination of high-resolution measurements in the spatial (Chandra) and spectral (Chandra, XMM-Newton) domain key to rule out shocks as the main source of [E]NLR ionization

How close/different are the X-ray cores of Seyfert and Radio Galaxies? We need extended study of complete samples to tell


Back-up material


Statistics (just a few examples!)Statistics (just a few examples!)

Sub-pc scale jets: 45%Seyferts: 47%

LINERS: 44%

Transition: 16%

VLA (0”.15)

VLBA (2-5 mas)

VLA: 197 VLBA+I: 44

Palomar Galaxies

(96% LLAGN)

Nagar et al. (2005)

Unresolved: 50%

Slightly recolved: 20%

Two components: 10%

Linear: 20%

87% (8.4 GHz)VLA-A (0”.25)

9812-μ AGNThean et al. (2001b)

Unresolved: 21%

Resolved: 79%

100% (18 cm; only >2mJy 8.4GHz sources observed)

MERLIN (0”.1-0”.3)

19CfAThean et al. (2001a)

Unresolved: 52%

Slightly resolved: 30%

[Linear: 32%]

85% (3σ, 6 cm)

71% (3σ, 20 cm)

VLA (1”)52Palomar Seyfert

Ho & Ulvestad (1999)

MorphologiesDetection fraction

Instnt

(reson)

#SamplePaper


““Frustrated jets” in Seyferts?Frustrated jets” in Seyferts?

Large fraction of Seyfert Galaxies have large-scale bipolar super-bubbles [Colbert et al. 1996a,b]

(Cecil et al. 2001, 2002)

• Spectra of components A and B is similar to GPS spectra → regions of interactions between jet and dense external medium• Time evolution of radio continuum emission behave as expected for a jet interacting with a clumpy medium• Jet momentum spread in the interaction site may explain the bubbles (Saxton et al. 2005)

• Generalizing this scenario may explain why jets in Seyfert rarely propagate on kpc scales


Interpretation of the fundamental Interpretation of the fundamental planeplane Scale-invariant jetsScale-invariant jets [Heinz & Sunyaev 2003][Heinz & Sunyaev 2003]

– Radio luminosity scales with BH mass and accretion Radio luminosity scales with BH mass and accretion rate independently of the jet modelrate independently of the jet model

– Scaling depends on Scaling depends on α, and the electron distribution index → α, and the electron distribution index → on accretion physics onlyon accretion physics only

X-ray emission from BH accretion at a few percent X-ray emission from BH accretion at a few percent Eddington is consistent with radiative inefficient flow onlyEddington is consistent with radiative inefficient flow only

In low accretion rate sources, jet power is proportional to In low accretion rate sources, jet power is proportional to accretion poweraccretion power

Challenges? Seyferts and LL RGs Challenges? Seyferts and LL RGs seem to follow different planes seem to follow different planes [Wang et al. 2006; Panessa et al. 2007][Wang et al. 2006; Panessa et al. 2007]

(Wan

g et

al.

2006

)


Role of absorptionRole of absorption

Mkn348

• pc-scale double sources with brightness temperature 1010-11K → synchrotron emission• Historical variability → one sided-jet• One sideness → free-free absorption by ne≥2·105 cm-3 T≥8000 K (X-ray absorption) or ne≥107 cm-3 T≥ 106.6 K• [Exceptional sources: they more powerful than many 12μ sources, against the general correlation between radio power and size → jet starts very luminous and then decay, CSO/GPS link?]

(Ulv

esta

d et

al.

1999

b)

(Ulv

esta

d et

al.

1999

a)


NLSy1NLSy1

• ≤7% of NLSy1s are radio-loud (against 10-20% of “normal” Seyfert 1s)

• Stack of 19 VLA observations of undetected NLSy1 (R≤0.27)

• 5/6 radio-loud NLSy1 are GPS/CSS

NLSy1 vs. GPS[Guainazzi et al. 2006; Vink et al. 2006]

(Komossa et al. 2006)(Gallo et al. 2006)


Bicknell´s (2002) argumentBicknell´s (2002) argument

L(O[III])L(O[III])≈10≈104242 erg s erg s-1-1 implies L implies Ljetjet≈10≈1044 44 erg serg s-1 -1 for the for the

same scale law as in GPS/CSSsame scale law as in GPS/CSS However, for standard radio power to jet However, for standard radio power to jet

luminosity conversion factors Pluminosity conversion factors P5GHz5GHz≈10≈102323 Jy implies Jy implies

LLjetjet≈10≈1041 41 erg serg s-1-1

This implies that the electron to positron fraction is This implies that the electron to positron fraction is small (≈0.01)small (≈0.01)

Jets flows in Seyferts could start from the inner 10 Jets flows in Seyferts could start from the inner 10 gravitational radii as magnetically-driven windsgravitational radii as magnetically-driven winds

Radio emerges from internal schoks in the Radio emerges from internal schoks in the plasma.plasma.


LLAGN (LLLAGN (LHHαα<10<104040 erg s erg s-1-1))

(Nagar et al. 2005)

Main differences between LINERS and Seyfers lower nuclear gas densities lower accretion rate more efficient in launching sub-pc scale jets GBC analogy?

LINERS are in a "low/hard state" Seyfert in a "high/soft" state

Cor

rela

tion

bet

wee

n s

ub

-pc

rad

io

pow

er a

nd

BH

mas

s, g

alax

y lu

min

osit

x


Radio jet orientationRadio jet orientation

The distribution of angles between the radio jets and the galaxy disk is consistent with being random, provided that a galaxy is recognized as a Seyfert only if the angle

between the jet and the l.o.s. is ≤40º

[consistent with a basic assumption of the Seyfert unified scenarios]

(Schmitt et al. 2001)(Kinney et al. 2000)

Misalignment between the accretion disk and the host galaxy disk [also Ulvestad & Ho 2001]:• Feeding of a misaligned disk: warping by slef-irradiation instabilities, misaligned gravitational potential, nuclear star clusters, Bardeen-Petterson instabilities …• Misaliged inflow: minor mergers, capture of nuclear star clusters or individual molecular clouds …


Unification scenario and radio Unification scenario and radio emissionemission

Seyfert 1s and 2s are indistinguishable in:

• radio luminosity• radio size

Oddities:

• Sources with ionization cones host larger radio sources

• Sources with hidden BLR are more radio powerful

• observational bias?

(Thean et al. 2001; also U

lvestad & H

o 2001)

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Matteo Guainazzi European Space Astronomy Center of ESA Villafranca del Castillo (Spain)