Studying the Cosmological evolution of
supermassive black holes with
LOFAR
“Astrophysics with E-LOFAR”, Hamburg, 18/9/2008
Andrea MerloniExcellence Cluster Universe &
Max-Planck Institut für Extraterrestrische Physik
Garching, Germany Picture from Di Matteo et al. (2007)
Sgr A* M87
Black Holes in the local Universe
ΩSMBH≈2.710-6
Accretion over cosmological times, Active Galactic Nuclei, galaxy evolution
Ωbaryon≈4.510-2 ; Ωstars≈2.510-3
Ω*BH≈710-5 [Fukugita & Peebles (2007)]
Stellar physics, SN explosions, GRB
Accretion power: hard X-rays census
Hopkins and Beacom (2006)
Brusa et al. 2008
Best constraints on high-z (z>3) X-ray selected AGN evolution (XMM-COSMOS)
Absorption-corrected X-ray LF, a, + contribution of Compton thick AGN from XRB synthesis model (~20-30%) of total grown mass
SMBH vs TOTAL stellar mass densities
Perez-Gonzalez et al.(2007)z1 3
rad=0.07
Radio cores scaling with M and mdot
A “fundamental plane” of active BHs [Merloni et al. 2003; Falcke et al. 2004]
See also Ho 2002; Greene, Ho and Ulvestad 2003
Log Log
Log
Log
R*=(FR/Fbol)(max/5GHz)
Using the FP to search for mode changes
LLAGN, FRI RLQ,FRII
RQQ
Cyg X-1
Merloni and Heinz (2007)
• By studying the nuclear properties of the AGN we can establish a link between jet power and accretion power
• The observed slope (0.50±0.045) is perfectly consistent with radiatively inefficient “jet dominated” models (see E. Churazov’s talk)
Log Lkin/LEdd=0.49 Log Lbol/Ledd - 0.78
Low Power AGN are jet dominated
Bîrzan et al. (2008)
Extended Radio/LKin relation
Total Lobes only
- Larger scatter: aging, entrainment, intrinsic differences in B field strength and particle content.- Use cut-off freq. to account for aging gives tighter relation
Merloni and Heinz (2007)
Observed LR (beaming)Derived from FP relation
Monte Carlo simulation:Statistical estimates ofmean Lorentz Factor~8
Slope=0.54
Slope=0.81Log Lkin=0.81 Log L5GHz +11.9
Core Radio/LKin relation: effects of beaming
Koerding, Jester and Fender (2007)
Kinetic Energy output and efficiency
Merloni and Heinz. (2008)
• First and foremost, LOFAR excellent sensitivity will crucially expand our knowledge of the faint end of RLF (and extend it to high z)
• Feedback from radio-emitting AGN important, but:
• How to routinely calculate kinetic power output?
• Multi-wavelength approach: Low- and High-freq radio obs + X-rays
• Two steps are needed
• Deep pointings of nearby radio galaxies, jets and clusters to calibrate Lradio vs. Lkin relation
• Use LOFAR surveys to build robust kinetic luminosity function
• Arcsec resolution crucial for faint AGN identification!
Issues for (E-)LOFAR…