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Feedback Driven by Radio Sources

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Presentation on theme: "Feedback Driven by Radio Sources"— Presentation transcript:

1 Feedback Driven by Radio Sources
Brian McNamara University of Waterloo Perimeter Institute for Theoretical Physics Harvard-Smithsonian Center for Astrophysics Baltimore, STScI May, 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 Hot atmospheres
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 erg s-1 exceeds radio synchrotron power erg s-1 . implies cooling flow: ne ~10-1 cm-3 M = M yr-1 . Cooling flow problem: star formation ~ 1% M Problem in clusters and normal gEs

4 Chandra X-ray Observatory
Hydra A MS0735 Cavities ~10 to 100kpc across. Perseus

5 X-ray + radio = mechanical feedback
Hydra A McN +00, Kirkpatrick+11 MS0735 McN + 05,09 200 kpc 1 arcmin Cavities ~10 to 100kpc across. Energy input is the sum of the cavity's internal energy and the work done to inflate it. For a cavity filled with relativistic particles E = 4PV. Using cavity volume and local ICM gas pressure can calculate. 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:

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:

11 A1664 SFR ~ 20 Mo yr -1 A1835 SFR > 100 Mo yr-1 Pcav ~ 1045 erg s-1
Residual cooling: UV emission from star formation in molecular-gas-rich BCGs A1664 X-ray Lyα ~ Mo of gas Edge & Frayer 02 A1835 X-ray Lyα R cavity O’Dea + 10 A1664 SFR ~ 20 Mo yr 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 Classical cooling flow problem essentially solved:
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 Pjet~ 3x1046 erg s-1 Ejet ~ 1062 erg ~1000 Myr-1
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 removal of metal-enriched, cooling X-ray gas out of BCG and into ICM
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 Radio AGN Heating of Cluster Atmospheres Over Time
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 Wise + 07 320 MHz + 8 GHz 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 , and in prep Challenge: sample selection, jet power proxy

21 Scaling between jet cavity (mechanical) power and radio luminosity
1.4 GHz 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 J 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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