The disk-jet link:X-ray and radio monitoring of PKS 0558-

504

Mario Gliozzi (GMU)I. Papadakis (Crete) W. Brinkmann

(MPE) L. Kedziora-Chudczer (Sidney)

*Disk-jet connection*AGN-GBH analogy *PKS 0558-504 in Grand Unification Model *Results from RXTE & radio monitoring *Conclusions & future work

Disk & Jet

*Basic Ingredients of BH systems: Most evident manifestations of BH presence

*Growing evidence (theory, observations, simulations) of strong accretion-ejection link: No jet without accretion but not vice versa

*Main Goals:1) Understand the conditions leading to jet formation/quenching2) Assess jet role in energetics of the system

X-ray & Radio monitoring

Same phenomena occur on different scales: analogy GBHs -AGN

Previous studies demonstrate crucial role of radio X-ray monitoring:X-rays track the accretion activityRadio tracks the jet activity

Microquasar GRS1915+105 [Mirabel et al. 1998]

BLRG 3C120 [Marscher et al. 2002]

Grand Unification Model

2 main spectral states: 1) Low/Hard State (LS) and 2) High/Soft State (HS)

GBHs scaled down versions of AGN:AGN classes correspond to GBHs in different spectral states [e.g., Mc Hardy et al. 2006]

LS energy spectrum:

E [keV]

[Fig from Zdziarski & Gierlinski 2004]

HS energy spectrum:

E [keV]

Grand Unification Model

2 main spectral states: 1) Low/Hard State (LS) and 2) High/Soft State (HS)

GBHs scaled down versions of AGN:AGN classes correspond to GBHs in different spectral states [e.g.,Mc Hardy et al. 2006]

LS power spectrum: HS power spectrum:

[GX 339-4 Homan & Belloni 2004]

Grand Unification Model

2 main spectral states: 1) Low/Hard State (LS) and 2) High/Soft State (HS)

GBHs scaled down versions of AGN:AGN classes correspond to GBHs in different spectral states [e.g.,Mc Hardy et al. 2006]

LS radio properties: HS radio properties:

Persistent radio emissionCorrelation with X-rays: LR~LX

0.7

Emission from compact jet

[Fender et al. 2004; E. Gallo et al. 2004;]

Weak/absent radio emissionJet quenching

[Cyg X-1 Sterling et al. 2001]

GBH Intermediate State

HID: model-independent way to describe GBH evolutionExistence of Intermediate spectral State (IS)

IS energy spectrum:

[Fig from Zdziarski & Gierlinski 2004]

[GX 339-4 Homan & Belloni 2004]

GBH Intermediate State

HID: model-independent way to describe GBH evolutionExistence of Intermediate spectral State (IS)

IS power spectrum:

[Fig from Homan & Belloni 2004]

GBH Intermediate State

HID: model-independent way to describe GBH evolutionExistence of Intermediate spectral State (IS)

IS radio properties:

Transient & strong radio emissionSteep spectrumLarge bulk Lorentz factorMost powerful jet ejections

[GRS1915+105 Mirabel & Rodriguez 1998]

AGN-GBH Correspondence

IS requirements: * high accretion rate* strong radio emission* steep energy spectrum* PSD with QPOs

LS LLAGN Based on generalization of HID [Koerding et al. 2006]

Based on “fundamental plane” [Merloni et al. 2003; Falke et al. 2004]

HS Seyfert 1 Based on PSD [Uttley et al. 2002; Markowitz et al. 2003; McHardy et al. 2006]

IS ?

Importance of finding IS-analog AGN: frozen look of BH systems during major ejections

PKS 0558-504

Radio-loud: R~30 [Siebert et al. 1999]

BH mass: MBH~4x107 Msolar [Wang et al. 2001]

X-rays: Bright, Steep PL (Г~2.2), Variable [Gliozzi et al. 2007] Extremely variable: 67% flux variation in 3’ [Remillard et al. 1991]

In principle any radio-loud NLS1 satisfies basic requirements for IS,

but only few of these objects [Komossa et al. 2005]

only PKS 0558-504 bright enough for RXTE monitoring(F2-10 keV ~ 2x10-11 erg cm-2 s-1, L2-10 keV ~ 1045 erg s-1)

Requirements for IS

High accretion rate?

Jet radio emission?

Lbol ~ LEdd

Even considering MBH~ 5 Mvirial [Marconi et al. 2008]

and different bolometric corrections [Vasudevan & Fabian 2007]

Yes

Maybe (wait and see)

PSD with QPO?

No (at least not yet)Answer after XMM AO7

5 orbits (660ks PI Papadakis)

Energy spectrum match?

Comptonization [O’Brien et al. 2001; Brinkmann et al. 2004]Ionized Reflection [Ballantyne et al. 2001; Crummy et al. 2006]SLIM disk [Haba et al. 2008]Beamed emission [Remillard et al. 1991; Gliozzi et al. 2001]

Maybe (but spectral degeneracy)

Additional diagnostics for IS

From model-independent studies of spectral variability:

1) Fractional variability flattens in IS from LS to HS [Gierlinski & Zdziarski 2005]

E [keV]

LS HSIS

2) Short-term variability Cyg X-1 during IS characterized large flux changes without spectral variations

[Malzac et al. 2006]

RXTE monitoring of PKS 0558-504

Campaign:Started in March 2005;monitoring campaign under way

Sampling: 1 observation every 2 days+ 3 periods of denser coverage (2 observations per day)[Gliozzi et al. 2007]

Soft [2.5-5 keV] andHard [5-15 keV] fluxeshighly variable on day-monthtimescales.

Flux variability accompaniedby weak spectral variability.

Flux-Flux PlotPlot Hard [5-15 keV] versus Soft [2.5-5 keV] count rate to characterize the spectral variability [e.g., Churazov et al. 2001; Taylor et al. 2003] .

Two possible scenarios:1) If power-law trend: Spectral variability explained by pivoting. 2) If linear trend: Constant spectral shape with 2 components [Zdziarski et al. 2002]

Linear trend

Intercept = 0

no spectral pivoting

no contribution from hard component

Common physical origin for Soft & Hard

Fvar- E Plot

Plot Fractional variability Fvar vs energy

Fvar=√(S2- <σerr2>)/<x>

Different from typical jet-dominated behavior: Fvar α E[Gliozzi et al. 2006]

Mrk 501

Constant trend reminiscent of GBHs in IS[Gierlinski & Zdziarski 2005]

HR-ct Plot

Plot of hardness ratio HR=[5-15 keV]/[2.5-5 keV] vs. count rate Constant trend reminiscent of Cyg

X-1in IS[Malzac et al. 2006]

Different from typical jet-dominated

behavior: HR α ct[Gliozzi et al. 2006]

Mrk 501

Radio Observations

ATCA Imaging:18 GHz

F.O.V= 9”x13” beam=0.5”

(1”=2.4 kpc)

Source unresolved

Radio Observations

ATCA Imaging: 8.6 GHz

F.O.V= 18”x27” beam=1”

(1”=2.4 kpc)

2 symmetric lobes resolved(d=14 kpc)

Radio Observations

ATCA Imaging: 4.8 GHz

F.O.V= 38”x58” beam=2”

(1”=2.4 kpc)

2 symmetric lobes resolved(d=14 kpc)

Radio Observations

VLBI Imaging [S. Tingay]

jet resolved(R~100 pc)

Radio Monitoring

Radio emission highly variable

Timescales longer compared to X-rays

No trivial correlation with X-rays

but longer baseline needed

PKS 0558-504 IS-analog ?

High accretion rate?

Jet radio emission?

Energy spectrum match?

Yes

Yes

Typical Spectral variability?

Yes

PKS 0558-504 extraordinary object:high accretion rate AGN with strong radio jet,very bright, highly variable on all timescales.

Maybe: no evidence for reflection

Future Work

- From September 2008 PKS 0558-504 weekly monitored with SWIFT in Optical, UV, and soft X-ray to complement hard X-rays (RXTE) and hopefully radio monitoring.

-5 XMM-Newton orbits in AO7 for deep investigation of PSD (QPOs) and breaking spectral degeneracy via time-resolved spectroscopy.

- Further VLBI observations to investigate possible changes in the inner jet structure.