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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
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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 Same phenomena occur on different scales: analogy GBHs -AGN Previous studies demonstrate crucial role of radio X-ray monitoring: X-rays track the accretion activity Radio tracks the jet activity Microquasar GRS1915+105 [Mirabel et al. 1998] BLRG 3C120 [Marscher et al. 2002]
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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]
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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]
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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 emission Correlation with X-rays: L R ~L X 0.7 Emission from compact jet [Fender et al. 2004; E. Gallo et al. 2004;] Weak/absent radio emission Jet quenching [Cyg X-1 Sterling et al. 2001]
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GBH Intermediate State HID: model-independent way to describe GBH evolution Existence of Intermediate spectral State (IS) IS energy spectrum: [Fig from Zdziarski & Gierlinski 2004] [ 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) IS power spectrum: [Fig from Homan & Belloni 2004]
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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 [GRS1915+105 Mirabel & Rodriguez 1998]
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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
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PKS 0558-504 Radio-loud: R~30 [Siebert et al. 1999] BH mass: M BH ~4x10 7 M solar [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 (F 2-10 keV ~ 2x10 -11 erg cm -2 s -1, L 2-10 keV ~ 10 45 erg s -1 )
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Requirements for IS High accretion rate? Jet radio emission? L bol ~ L Edd Even considering M BH ~ 5 M virial [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)
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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] E [keV] LSHSIS 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] Soft [2.5-5 keV] and Hard [5-15 keV] fluxes highly variable on day-month timescales. Flux variability accompanied by weak spectral variability.
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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] Linear trend Intercept = 0 no spectral pivoting no contribution from hard component Common physical origin for Soft & Hard
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F var - E Plot Plot Fractional variability F var vs energy F var =√(S 2 - )/ Different from typical jet-dominated behavior: F var α E [Gliozzi et al. 2006] Mrk 501 Constant trend reminiscent of GBHs in IS [Gierlinski & Zdziarski 2005]
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HR-ct Plot Plot of hardness ratio HR=[5-15 keV]/[2.5-5 keV] vs. count rate Constant trend reminiscent of Cyg X-1 in IS [Malzac et al. 2006] Different from typical jet-dominated behavior: HR α ct [Gliozzi et al. 2006] Mrk 501
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Radio Observations ATCA Imaging:18 GHz F.O.V= 9”x13” beam=0.5” (1”=2.4 kpc) Source unresolved
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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)
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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)
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Radio Observations VLBI Imaging [S. Tingay] jet resolved (R~100 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? Jet radio emission? Energy spectrum match? 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
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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.
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