X-ray / Radio Correlation for Sub-Eddington Black Holes Heino Falcke ASTRON, Dwingeloo University of Nijmegen, with Elmar Körding, Sera Markoff, Geoff Bower et al.

What if … … jets matter? If XRBs are microquasars, what can we learn from AGN jets? Are jets important at wavelengths other then radio? Mirabel & Rodriguez 1994

Emission from Jets: Across all Wavebands 3C273 M87 jet spectra of bright knots Meisenheimer et al. (1997) Optical and perhaps X-ray synchrotron require TeV electrons and continuous re-acceleration in the jet!

BL Lacs – A Pure Jet Spectrum BL Lacs are thought to be beamed FRI radio galaxies (low power!) In BL Lacs the emission is dominated by the jet due to relativistic beaming. But there is also no evidence for any disk spectrum. The jet spectrum resembles a „camel‘s back“. Radio – optical – X-rays: synchrotron from jet X-ray – TeV: inverse Compton from inner jet Synchrotron from jet Inverse Compton from jet Fossati et al. (1998)   S

The Synchrotron Scaling of Jets In XRBs: Jets Should Contribute to X-rays! max  M dot 2/3 r min -1  M dot,edd 2/3 M bh 2/3 M bh -1  M bh -1/3 turnover frequency in stellar black holes > blazars (also: B XRB >>B AGN )! S M bh ~10 9 R min max ~10 13 Hz S ~ -0.7 Radio/mm S M bh ~10 R min max ~10 15 Hz Opt/UV/X Radio/mm

The radio-optical spectrum of XRBs Radio-to-NIR spectrum is flat in the hard state. Both wavelengths scale up and down together. This strengthens identification as a joint power-law and suggests synchrotron from a jet. The steady jet appears in the hard state with the X- ray power law. (Fender 2000) V404 Cyg

Jet Model for the X-Ray Binary XTE J MFF model: X-rays are from the jet, not the disk!

Jet Model for the X-Ray Binary XTE J Consistent with MFF jet model. Hynes et al. (2003) Variability SED: NIR-X-ray is one power law consistent with synchrotron

Reflection from Jet Emission Impinging on the Disk Markoff & Nowak (2003), subm. Incident radiation Reflected radiation Total spectrum ~20% reflection fraction (even without disk warping)

“Jetlags” in Cyg X-1 Properties of a Pivoting Rigid Power law Körding & Falcke, A&A, in press (now on astro-ph) energy-dependent phase lag (also fits auto- and cross-correlation) phase lag with Fourier frequency A jet-inspired mathematical prescription of X-ray variability: simple and effective.

Scaling of Jets: large, small, powerful and faint The basic shape of the broad- band jet spectrum is (relatively) invariant to changes in black hole mass and accretion rate. Simple scaling laws with M dot can be derived analytically (keeping dimensionless parameters constant).  Smaller black holes peak at higher frequencies.  Increasing Mdot increases flux density non-linearly.  X-ray/radio ratio changes with black hole mass! Scaling laws for Blandford & Königl jet cores. Falcke & Biermann (1995) Markoff et al. (2003) Falcke et al. (2003) see also: Heinz & Sunyaev (2003) and Merloni et al. (2003) black hole mass

X-ray/Radio Correlation: Scaling with Accretion Rate The X-ray emission in GX339-4 seems to tightly follow the radio emission. The slope is non-linear with α=1.40. Obviously the mass does not change - only the accretion rate. Analytic theory predicts α=1.39.  Jet scaling laws reproduce radio- x-ray slope perfectly. Markoff et al. (2003), Corbel et al. (2003) Falcke & Biermann (1995), Heinz & Sunyaev (2003) Jet-Model X-rays radio X-ray vs. Radio correlation (GX339-4) Radio jets are now confirmed! M 

Is the Radio/X-ray correlation slope universal for low/hard state XRBs? Gallo, Fender & Pooley 2003, MNRAS (see also talk by E. Gallo) Radio/X-ray correlation for sub-Eddington XRBs

“JDAFs” Jet-Dominated Accretion Flows How does the SED evolve with power? The SED has jet and disk contributions! Below a critical accretion rate, disks become radiatively inefficient (e.g., become advection dominated: ADAFs, BDAFs, CDAFs …).  At lower accretion rates disks become less and less prominent, jets remain strong.  Explains radio-loudness of LLAGN and low-state XRBs. Disk Jet L x,r low-state high-state (A/C)DAF + Jet jet domination – disk domination Körding, Falcke, & Markoff (2002); see also Fender, Gallo, & Jonker (2003)

Power Unification Many AGN do not show evidence for (strong) emission from the accretion disk: –BL Lacs –FR I radio galaxies –LINERs –Sgr A* –X-ray binaries in the low-hard state They all have relatively prominent radio jets or compact radio cores (e.g. LLAGN have 40% detection rate for cradio cores, Falcke, Nagar et al. 2000). Is their entire SED dominated by non-thermal jet-emission? thermally dominated non-thermally dominated

Collect radio and X-ray/optical emission for VLA and VLBA radio cores from sub-Eddington black holes: –Liners (Nagar et al. 2003) –FR Is (3C sample, Chiaberge et al. 2000) –BL Lacs –Sgr A* „Correct“ X-ray/optical flux for black hole mass.  Sub-Eddington AGN magically fall on XRB extension + pure jet model  Jet domination works very well!  Mass and accretion rate form a „fundamental plane“. X-ray/Radio Correlation: Scaling with Accretion Rate faint radio cores Corrected for mass M  M Falcke, Körding, Markoff (2003, A&A) (see also Merloni et al. 2003)

Ultra-Luminous X-ray Sources Are there microblazars? Claim: jets in X-ray binaries produce X-rays In the high-state some fraction of X-ray emission is from the jet.  Some X-ray binaries must be beamed microblazars (Mirabel & Rodriguez 1999)  Check with X-ray point sources in nearby galaxies (ULX) Chandra: M82

Population X – Beamed X-ray Binaries? Model X-ray binary point source population with a simple XRB evolution model 2 Populations: –NS (1.4 M  ) & BHs (5 M  ) 2 States: –Low/Hard (jet-dominated) –High/Soft (disk-dominated) Single ‚luminosity function' for accretion rates (powerlaw) Isotropic disk emission and relativistically beamed jet emission for  =5 jets. Deficient at the very highest luminosities? Are (some) ULXs beamed XRB jets? Körding, Falcke, Markoff 2002 See Poster!

Population X – 1000 Solar Mass Black Holes? Model X-ray binary point source population with a mass distribution model 2 Populations: –NS (1.4 M  ) & BHs ( M  ) Power law distribution for –accretion rates –black hole masses (up to 1000 M  ). Predicts a large fraction of intermediate mass black holes in the low/hard-state in the Milky Way! Körding, Falcke, Markoff 2002 See Poster!

Radio Monitoring of Ultra-Luminous X-Ray Binaries Multi-Epoch radio monitoring with the VLA at the highest resolution at 8 GHz. 6 Epochs for 10 sources No detections - only one (insignificant) 4.5 σ „event“ The radio non-detections fall into the M  range (unlikely to be background AGN) The only two previous radio detections were dominated by steep- spectrum emission (blobs!) Low-luminosity IMBH in the Milky Way should be radio sources. Körding et al. (2003)

The Galactic Center – The Least Luminous AGN Astrophysical Black Holes are characterized by two main parameters: –Mass M –Accretion rate M dot What happens as M and M dot change? Study the least luminous supermassive black hole we can see: Sgr A*. L(radio - x-ray) < erg/sec of Eddington Luminosity Sgr A* The central parsec of the Milky Way

Radio & X-ray Flaring in Sgr A* (like Cyg X-1 superflares?) X-ray: 5000% in 30 min radio: 20% in 30 min X-ray flare from inverse Comption X-ray flare from synchrotron Predicts: Strong NIR flaring mild NIR flaring Sgr A* falls on X- ray/radio correlation only in flare state! Jet Model Bower, Falcke, Sault, Backer (2002), ApJ Baganoff et al. (2001), Nature Markoff, Falcke, Yuan, Biermann (2001), A&A

Conclusion (Inner) jets are likely contributors to the SED – including X- rays – of almost any black hole. A jet can naturally do almost everything a corona does (spectrum, variability, reflection, cut-off, QPOs?). –Don’t equate every X-ray power law with a corona! At low accretion rates, the jet emission may dominate the disk. This allows one to define an X-ray/radio correlation as a function of Mass and Accretion Rate. –Largest uncertainty: mode of particle acceleration. This could lead to a large scatter! The scheme connects: XRBs, The Galactic Center, and (LL)AGN at sub-Eddington accretion rates.