The diskjet link: Xray and radio monitoring of PKS 0558504

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The disk-jet linkX-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
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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/quenching 2) Assess jet role in
energetics of the system
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X-ray Radio monitoring

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

Microquasar GRS1915105 Mirabel et al. 1998
BLRG 3C120 Marscher et al. 2002
Same phenomena occur on different scales analogy
GBHs -AGN
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Grand Unification Model
GBHs scaled down versions of AGN AGN classes
correspond to GBHs in different spectral states
e.g., Mc Hardy et al. 2006
2 main spectral states 1) Low/Hard State (LS)
and 2) High/Soft State (HS)
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Grand Unification Model
LS power spectrum
HS power spectrum
GX 339-4 Homan Belloni 2004
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Grand Unification Model
LS radio properties
HS radio properties
Persistent radio emission Correlation with
X-rays LRLX0.7 Emission from compact jet
Weak/absent radio emission Jet quenching
Cyg X-1 Sterling et al. 2001
Fender et al. 2004 E. Gallo et al. 2004
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GBH Intermediate State
HID model-independent way to describe
GBH evolution Existence of Intermediate
spectral State (IS)
GX 339-4 Homan Belloni 2004
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GBH Intermediate State
HID model-independent way to describe
GBH evolution Existence of Intermediate
spectral State (IS)
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GBH Intermediate State
HID model-independent way to describe
GBH evolution Existence of Intermediate
spectral State (IS)
IS radio properties
Transient strong radio emission Steep
spectrum Large bulk Lorentz factor Most powerful
jet ejections
GRS1915105 Mirabel Rodriguez 1998
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AGN-GBH Correspondence
Importance of finding IS-analog AGN frozen look
of BH systems during major ejections
IS requirements high accretion rate strong
radio emission steep energy spectrum PSD with
QPOs
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PKS 0558-504
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)

• Radio-loud R30
  Siebert et al. 1999

BH mass MBH4x107 Msolar
Wang et al. 2001
X-rays Bright, Steep PL (?2.2), Variable
Gliozzi et al. 2007
Extremely variable 67 flux variation in 3
Remillard et al. 1991
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Requirements for IS

• High accretion rate?
  

Jet radio emission?

Maybe (wait and see)

No (at least not yet) Answer after XMM AO7 5
orbits (660ks PI Papadakis)

PSD with QPO?

Energy spectrum match?

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Additional diagnostics for IS

• From model-independent studies of spectral
  variability

1) Fractional variability flattens in IS from LS
to HS
Gierlinski Zdziarski 2005
2) Short-term variability Cyg X-1 during IS
characterized large flux changes without
spectral variations
Malzac et al. 2006
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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

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Flux-Flux Plot
Plot 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

Common physical origin for Soft Hard
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Fvar- E Plot
Plot Fractional variability Fvar vs energy
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HR-ct Plot
Plot of hardness ratio HR5-15 keV/2.5-5 keV
vs. count rate Constant trend reminiscent of
Cyg X-1 in IS Malzac et al. 2006
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Radio Observations
ATCA Imaging18 GHz
F.O.V 9x13 beam0.5 (12.4 kpc)
Source unresolved
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Radio Observations
ATCA Imaging 8.6 GHz
F.O.V 18x27 beam1 (12.4 kpc)
2 symmetric lobes resolved (d14 kpc)
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Radio Observations
ATCA Imaging 4.8 GHz
F.O.V 38x58 beam2 (12.4 kpc)
2 symmetric lobes resolved (d14 kpc)
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Radio Observations
VLBI Imaging S. Tingay
jet resolved (R100 pc)
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Radio Monitoring
Radio emission highly variable Timescales
longer compared to X-rays No trivial
correlation with X-rays but longer baseline needed
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PKS 0558-504 IS-analog ?

• High accretion rate?
  

Yes

Jet radio emission?

Yes

Yes

Typical Spectral variability?

Energy spectrum match?

Maybe no evidence for reflection

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