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Feedback Driven by Radio Sources

Brian McNamara. Feedback Driven by Radio Sources. University of Waterloo. Perimeter Institute for Theoretical Physics Harvard-Smithsonian Center for Astrophysics. Baltimore, STScI May, 9 2012. Collaborators: P. Nulsen (CfA), H. Russell, CJ Ma , C. Kirkpatrick (Waterloo)

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Feedback Driven by Radio Sources

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  1. Brian McNamara Feedback Driven by Radio Sources University of Waterloo Perimeter Institute for Theoretical Physics Harvard-Smithsonian Center for Astrophysics Baltimore, STScI May, 9 2012 Collaborators: P. Nulsen (CfA), H. Russell, CJ Ma, C. Kirkpatrick (Waterloo) M. Wise (Astron), K. Cavagnolo (Waterloo), A. Vikhlinin (CfA)

  2. Mechanical Feedback in Radio AGN Review: Tucker, Tananbaum, Fabian 07, Scientific American Radio-mechanical heating in X-ray atmospheres of galaxies, groups, & clusters Evidence for actual feedback loop: cooling, star formation, AGN Consequences: quenching of cooling flows, red & dead phenomenon in ellipticals, color dichotomy in ellipticals Recent developments: 1.Metal-enriched, large-scale outflows in clusters 2. AGN heating of hot atmospheres in distant clusters

  3. Hot Atmospheres surrounding clusters and gEs thermal X-ray emission Hot atmospheres - Debris from stellar evolution - Heat & exhaust from SMBHs - Captured baryons NGC 1275 Perseus X-ray cooling cusp T≈107-8 K Z=0.2-1 Z A. Fabian X-ray luminosity 1044-45 erg s-1 exceeds radio synchrotron power 1040-42 erg s-1 . implies cooling flow: ne ~10-1 cm-3 M = 10-1000 M yr-1 . Cooling flow problem: star formation ~ 1% M Problem in clusters and normal gEs

  4. Chandra X-ray Observatory Hydra A MS0735 Perseus

  5. X-ray + radio = mechanical feedback Hydra A McN +00, Kirkpatrick+11 MS0735 McN + 05,09 200 kpc 1 arcmin 20 kpc Credit: H. Russell Perseus Fabian et al. 2008

  6. Mechanical AGN Feedback Regulates Cooling Chandra X-ray Observatory Hydra A “radio mode” feedback cooling gas Radiative cooling = AGN heating of hot gas heating cavities thermostatically controlled accretion 20 kpc ==> feedback loop Measure: T, ne = Pth, EAGN = 1059 erg Key evidence: McN+00 -AGN mechanical power matched to cooling rates -Short (<109 yr) cooling times in all systems Birzan+04, Rafferty+06, Dunn Fabian 06 Voigt & Fabian 04 Reviewed by McNamara & Nulsen 07 ARAA, McNamara & Nulsen 12, NJP, arXiv:1204.0006

  7. Measuring Jet Power using X-ray Cavities • energy & age measured/estimated directly • measure mechanical (not synchrotron) power M ~1.2 shock 1) Cavity enthalpy (pV work + internal energy) pV cavity rnuc Nucleus accretion, spin McNamara + 00,01; Birzan + 04 Churazov 01 Theory: Ruszkowski, Heinz, Bruggen, Begelman, Voit, Churazov, T. Jones, etc. slow gas motions vg< cs,= gentle heating

  8. Mechanical power dramatically exceeds radio power Pjet > 1000 X Lradio radio Jet (cavity) power McNamara & Nulsen 07 ARAA cavity Birzan + 04 Radio Luminosity Key breakthrough: even weak radio sources mechanically powerful enough power to regulate or quench cooling, X-ray atmospheres

  9. AGN heating balances cooling in gE’s & Clusters Rafferty + 06 Birzan + 04 Dunn & Fabian 06 <heating> ≈ cooling cooling, jet power are correlated over seven decades in jet power heating knows about cooling: feedback jet power X-ray cooling luminosity Rafferty +06, O’Dea +08 Same process keeps ellipticals red & dead (Bower +06, Croton 06, Best +06) See McNamara & Nulsen 12 for recent update

  10. Conditions conducive to AGN Feedback Loop tcool > tcav cooling time profiles cooling time (108 yr) cooling time (109 yr) tc ≈ 108 yr Rafferty + 08 Voigt & Fabian 04 Rafferty + 08 cavity age Radius (kpc) McNamara & Nulsen 12, NJP Despite large AGN heating rates, central cooling times are short < Gyr AGN heating and radiative cooling timescales are similar Conditions for feedback H See Voit & Donahue 05, McNamara & Nulsen 07 ARAA, McNamara & Nulsen 12, NJP, arXiv:1204.0006

  11. Residual cooling: UV emission from star formation in molecular-gas-rich BCGs A1664 X-ray Hα Lyα ~1010 - 1011Mo of gas Edge & Frayer 02 Lyα A1835 X-ray R cavity O’Dea + 10 A1664 SFR ~ 20 Mo yr -1 A1835 SFR > 100 Mo yr-1 Pcav ~ 1045 erg s-1 • Fuel directly linked to cooling hot halo (not mergers) • X-ray cooling rate near star formation regions match SFR McN+ 06 Rafferty+08, Cavagnolo+08, Kirkpatrick + 08 ALMA data will arrive shortly!

  12. star formation cooling time threshold: tcool ~ 500 Myr Rafferty + 08 5 x 108 yr blue threshold blue red X-ray cooling time Cavagnolo + 08 Ha threshold Voit + 09 Cool gas & Star formation linked to cooling instabilities in X-ray atmospheres

  13. Upshot of all this: Classical cooling flow problem essentially solved: observed SFR ≈ classical cooling rate – heating rate Rafferty +06, O’Dea +08 Best + 06 Gas fueling star formation linked to hot atmospheres through cooling time – entropy star formation threshold Rafferty +08 Cavagnolo +08 Radio-mechanical AGN feedback loop For reviews McNamara & Nulsen 07 ARAA, 12, NJP Same process maintains red & dead ellipticals (Bower +06, Croton 06)

  14. Hot Outflows on Cluster Scales Newer stuff… Led by Clif Kirkpatrick

  15. MS0735 Cool, metal-enriched outflow X-ray metal map end up out here metals made here gas here used to be there Z~Z Fe outflow Z=0.3Z 200 kpc McN+09, 12 500 ks Chandra image VLA, HST RFe~300 kpc Pjet~ 3x1046 erg s-1 Powerful thrust: Ejet ~ 1062 erg Lifted/displaced mass ~ 1011 M ~1000 Myr-1 See also Simionescu + 08, Kirkpatrick 09,11

  16. Hydra A Cool, Metal Enriched Outflow cool, multiphase gas Iron enriched outflow Gitti + 11 Kirkpatrick + 09 Kirkpatrick + 09  ΔMFe = 2-7 x 107 M ΔMtot>1010M Mout > 100 M yr-1 R≈120 kpc AGN outflows disperse cool gas & metals into the ICM See also Simionescu + 08, O’Sullivan + 11, Nulsen + 05

  17. Iron enrichment radius scales with Jet power: drives hot gas out of galaxy MS0735 Hydra A AGN jet power 300 kpc 100 kpc Kirkpatrick +09, 11, 12 Metal enrichment radius Orientation of outflow correlates with radio and cavity orientation: jet driven outflows Outflow rates of tens to >100 Myr -1 – star formation quenched by heating and removal of metal-enriched, cooling X-ray gas out of BCG and into ICM Outflow rates comparable to cooling rates of hot atmospheres

  18. Finally… Radio AGN Heating of Cluster Atmospheres Over Time C.J. Ma Problems: 1. Hot atmospheres are ≈1 keV per particle “hotter” than expected? aka, “preheating” problem Kaiser (1991) 2. Quenching & declining numbers of distant cooling flows (Vikhlinin 07, Samuele + 11) See Ma + 11 Reviewed by McNamara & Nulsen 12

  19. Cluster Scale Atmospheric Heating: Hydra A Cluster z=0.05 Ejet > 1061 erg AGN outburst: swiss cheese morphology to hot atmosphere shock X-ray 380 kpc 6 arcmin cooling region 320 MHz + 8 GHz Wise + 07 Nulsen + 05 McN + 00

  20. AGN Heating in Distant Clusters Sample: 8 serendipitous & all-sky X-ray surveys: 685 ROSAT clusters • Procedure: • Cross Correlate cluster X-ray positions with NRAO VLA Sky • Survey radio sources • 1043 < Lx < 1046 , 0.1 < z < 0.9 • Radio detection threshold > 3 mJy • Correct for background as function of flux • Calculate jet power using cavity power scaling relation at 1.4 GHz • Calculate heating rate per particle C.J. Ma + 2011, and in prep Challenge: sample selection, jet power proxy

  21. Scaling between jet cavity (mechanical) power and radio luminosity 1.4 GHz 200-400 MHz what happens here? Saturated scaling Pcav (1042 erg s-1) Ma + in prep Pcav ~ 100 Lrad Z>0.3 MACS Clusters Hlavacek-Larrondo + 11  Cavagnolo + 10 Birzan + 04,08 Lradio (1040 erg s-1)

  22. Radio/Mechanical Heating Rate in clusters from z = 0.2-0.7 “preheating rate” Constant heating from z=2 Evolution of radio LF from z=2 R<250 kpc including powerful radio sources  saturated scaling  excluding powerful radio sources Ma + in prep - Heating (jet power) rises slowly with X-ray atmospheric luminosity, and redshift - Heating per gas particle dominant in low-mass clusters - Gradual heating over time significan addition to Kaiser’s “preheating” scenario Consequences: excess entropy in clusters (Voit 05, Kaiser 91) declining numbers of distant cooling flows (Santos 10, Vikhlinin 06, Samuele 11) Caveat: calibration of mechanical heating at high radio power

  23. Summary • Relatively weak radio AGN can be mechanically powerful • Powerful enough to suppress cooling hot halos • Strong evidence for a self-regulating feedback loop • Star formation, jets linked to central X-ray cooling time • Suppress star formation, disperse metals throughout LSS • AGN heating important over nearly half the age of universe • Low-mass X-ray halos heated efficiently • Gradual AGN heating significant • See McNamara & Nulsen 12, NJP & arXiv for recap of this talk

  24. Sample hundreds of Clusters from ROSAT NRAO-VLA Sky Survey (NVSS) ROSAT X-ray Imaging J1221+4918 z = 0.7 Lx = 1.2x1045 erg s-1 kT = 6.5 keV Ma + 11 Host galaxies cannot be identified using NVSS images X-ray cavities cannot be identified in short X-ray exposures

  25. New Large X-ray - Radio Cluster Survey “normal” clusters 685 clusters, 8 surveys Lx = 3x1043 – 1046 erg s-1 Radio detection fraction ~ 60%

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