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Two distinct Accretion processes in radio galaxies

Two distinct Accretion processes in radio galaxies. Huub Röttgering Leiden Observatory. Big Question: Coupled formation and evolution of Black holes / AGN Galaxies Large Scale Structure Some recent key results

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Two distinct Accretion processes in radio galaxies

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  1. Two distinct Accretion processes in radio galaxies Huub Röttgering Leiden Observatory

  2. Big Question: Coupled formation and evolution of • Black holes / AGN • Galaxies • Large Scale Structure • Some recent key results • AGN Feedback deposits large amounts of energy influencing the evolution of clusters and galaxies • Hierarchical clustering lead to most massive BH in the most massive galaxies which are in the most massive clusters • z>2 powerful radio galaxies are located in protoclusters (Overzier, Venemans, Kurk, Miley, de Breuk, van Breugel, Maschietto, van Breugel, Pentericci, Carilli, HR et al.) • Spatially resolved observations of nearby tori • Raban, Jaffe, Meiserheimer, Tristam, HR • Radio loudness is a strong function of galaxy mass

  3. VLT interferometer observations with MIDI of NGC 1068 Correlated Flux density spectrum UV plane

  4. Image of the torus of NGC 1068 • Two components: • Hot 800K, 1.4x0.5 pc • “funnel” • Cool 300K 3x4 pc • torus • Raban, Jaffe, HR, • Meisenheimer, Tristam • in prep. • 9 other AGN show ‘similar • Structure, except the radio • Galaxy CenA that does • not seem to have a torus 8 micron image Box: 60*60 milli-arcs

  5. Big Question: Coupled formation and evolution of • Black holes / AGN • Galaxies • Large Scale Structure • Some recent key results • AGN Feedback deposits large amounts of energy influencing the evolution of clusters and galaxies • Hierarchical clustering lead to most massive BH in the most massive galaxies which are in the most massive clusters • z>2 powerful radio galaxies are located in protoclusters (Overzier, Venemans, Kurk, Miley, de Breuk, van Breugel, Maschietto, van Breugel, Pentericci, Carilli, HR et al.) • Tori exist, but not in all AGN • Raban, Jaffe, Meiserheimer, Tristam, HR • Radio loudness is a strong function of galaxy mass

  6. For massive galaxies, the rate of activity and energy output sufficient to heat their hot halos (Best et al. 2005)

  7. Key questions • How does the radio loud fraction evolve with z? • How does the radio loud fraction depend on the environment? • How does AGN activity depend on accretion mode ? • Cold accretion / quasar mode / “torus mode” • Activity due to a merging event • Hot accretion / ``radio mode;; • Activity due to hot gas cooling • Topic of Cyril Tasse’s thesis • Best, Cohen, Le Borgne, Pierre, HR, et al.

  8. XMM-LSS survey • 10 sqr degree of XMM data • Spitzer Swire survey • CFHTLS (u,g,r,i,z) survey with 3 million galaxies • GMRT and VLA surveys 74, 230, 325 and 610 MHz • Complete catalogue with for each object: • Phot-z, galaxy mass, specific sfr, AGN loudness, density of its environment

  9. Evolution of the mass-fraction A break appears at log(M/Mo) = 10.5-10.8 Upturn of the radio LF due to less massive galaxies become more active Fraction of galaxies that are radio loud Z=0: Log(P1.4)>24 Z=0: Log(P1.4)>25 9.5 10.5 11.5 Log(M/Mo)

  10. 450 450 kpc Overdensity as a function of scale 250 kpc 75 kpc

  11. Difference in Density Radio source host and normal galaxy • Higher galaxy mass radio galaxies in clusters • Lower galaxy mass radio galaxies are in “pairs” • Cold accretion - due to merging more dominant at higher z ? • The reason for the upturn in the radio LF? 10.0 10.5 11.0 Log(M/Mo)

  12. Normalized IR excess for radio loud galaxies Only excess/torus emission for the lower mass galaxies Delta IR 10.5 10.5 11 Log(M/Mo)

  13. Summary • Radio galaxies with Log(M/Mo) > 10.5 • Steep fraction-mass relation • Located in overdensities of scale 450 kpc • Do not have IR excess Identify with accretion of hot gas • Radio galaxies with Log(M/Mo) < 10.5 • Flatter fraction-mass relation • located in overdensities of scales of 75 kpc • Have an IR excess Identify with merging event driving cold gas to the center

  14. What about X-ray AGN? Similar analysis for 200 type-2 X-ray AGN with 0.1<z<1.2 From Pacaud et a. 2006

  15. X-ray AGN behavior similar to lower mass radio galaxies Also in quasar mode? ‘flat’ fraction-mass relation IR excess: torus In field or ‘pairs’ 10.0 10.5 11.5 Log(M/Mo) 10.0 10.5 11.5 Log(M/Mo)

  16. Next steps

  17. LOFAR opens up the last ``unexplored’’ wavelength region • Unique frequency range  ~ 10 - 240 MHz • Unprecedented sensitivity • Time Line 2007: 4 stations 2008: 20 stations ~ 20 km 2010: 50 stations ~ 700 km • Science • Reionisation, cosmic rays, transient radio sources • z>6 radio galaxies, clusters and distant starbursts, Specifically • Feedback processes • Evolution of AGN activity

  18. Low Band Antennas: 30-80 MHz (the not enclosed) High Band Antennas: 115-240MHz Phased arrays: beams are formed electronically and not mechanically

  19. Configuration NL lofar: 20-25 core Stations & 20-25 outer stations E-lofar: 20-30 European stations?

  20. 60 MHz (1 %) LOFAR map with 800 sources (Oct 07)

  21. LOFAR detection of a z = 4.2 radio galaxy! 60 MHz (1 %) LOFAR map with 800 sources (Oct 07)

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