Caltech Apr06

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Radio-galaxy feedback and the cores of galaxy clusters:

Radio-galaxy feedback and the cores of galaxy clusters Chris Reynolds Dept. of Astronomy andamp; Center for Theory and Computation University of Maryland

Collaborators:

Collaborators Steve Allen (KIPAC/Stanford) Laura Brenneman (UMd) Elyse Casper (UMd) Yun-Young Choi (KIAS) Andy Fabian (Cambridge) Sebastian Heinz (MIT) John Stocke (Colorado) Jim Stone (Princeton) John Vernaleo (UMd)

Outline:

Outline The importance of supermassive black holes for the formation/properties of galactic scale structure ('AGN Feedback') The feedback between AGN and the hot gas in galaxy clusters Problems with simple hydrodynamic models Possible resolutions The fueling of radio-galaxies 'Inefficient accretion' may not be so inefficient!

Slide4:

I : Black Hole Feedback & Galaxies:

I : Black Hole Feedback andamp; Galaxies Several lines of evidence suggesting a connection between supermassive black holes and the formation/properties of galaxies… Correlation between black hole mass and velocity dispersion of galactic bulge Paucity of high-mass galaxies requiring highly-efficient feedback process Lack of cold gas in post-merger elliptical galaxies 'Entropy problem' of the intracluster medium 'Cooling flow problem' of the intracluster medium

Slide6:

Gebhardt et al. (2000); Ferrarese andamp; Merritt (2000) Tight relationship between black hole mass and galaxy properties

I : Black Hole Feedback & Galaxies:

Semi-analytic modeling of the galaxy luminosity function…:

Semi-analytic modeling of the galaxy luminosity function… Cole et al. (2000); Benson et al. (2003) Faint-end flattening explained through star formation feedback. Need more efficient form of feedback to produce bright-end than star formation!

Post-processing of the Millennium Run :

Post-processing of the Millennium Run Croton et al. (2006)

I : Black Hole Feedback & Galaxies:

Slide11:

Di Matteo et al. (2005)

I : Black Hole Feedback & Galaxies:

Slide13:

Virgo cluster (DSS) Virgo cluster (XMM) Matsushita et al. (2002)

Excess entropy in the ICM:

Excess entropy in the ICM LX-T relation Self-similar collapse gives LT2 Actually observe LT3 ICM in lower-mass clusters is under-dense!  ICM possesses excess entropy compared with self-similar collapse model Entropy injected at high-redshift (Bryan andamp; Voit 2005) Galactic winds, AGN, thermal conduction, or radiative cooling? Bryan andamp; Voit (2005)

I : Black Hole Feedback & Galaxies:

Cooling Flows…:

Cooling Flows… (Deprojected) X-ray data allow us to determine density and temperature Cooling time… Find that inner 100kpc of relaxed ICM atmospheres possess cooling times less than 1010yr Unless offset, would expect significant cooling Abell 4059 (DSS and Chandra) Choi et al. 2004

Cooling Flows…:

Cooling drives star formation?:

Cooling drives star formation? XMM-Newton OM study (Hicks andamp; Mushotzky 2005)

Slide19:

High-resolution spectra of clusters with XMM Spectral line analysis clearly shows gas cooling from kT~5keV to 1-2keV But no cooling below 1-2keV is apparent! Strong evidence that the ICM is heated Likely to be low-z manifestation of same feedback that truncates massive galaxy formation! XMM-RGS data for A1835 (Peterson et al. 2001) Also, Tamura et al. (2001); Peterson et al. (2005)

II : Radio-galaxy feedback in clusters of galaxies:

II : Radio-galaxy feedback in clusters of galaxies Many clusters show undisputed signatures of radio-galaxy/ICM interactions Signatures ICM cavities Ghost cavities Cold filaments Shocks and compression waves Perseus A (ROSAT-PSPC) Heinz, Reynolds andamp; Begelman (1998) Bohringer et al. (1995)

Chandra observations of cooling-core clusters:

Chandra observations of cooling-core clusters Cygnus-A Smith et al. (2002) Hydra-A Nulsen et al. (2004) Virgo/M87 Young et al. (2002) Synopsis: Jet-blown cavities common 'Ghost' cavities common Shocks are elusive! Abell 4059 / PKS2354-35 Heinz et al. (2002)

Slide22:

Abell 4059 (122ks Chandra Observation) [Casper et al., in prep.]

Slide23:

Unsharp mask of the 900ks Chandra observation of the Perseus cluster (Fabian et al. 2005)

Radio-galaxy feedback:

Radio-galaxy feedback Key Questions Can a quasi-stationary state be established whereby AGN heating balances ICM cooling? What is the physics of the ICM heating process? How does the AGN fueling get regulated? How dramatic are excursions from average state? How exactly is the AGN fueled? Accretion of the hot ICM/ISM or cold gas? What is the efficiency of the accretion?

Slide25:

Episode of jet activity produces Outward propagating shock Cavity/plume structure Sound waves andamp; weak shocks (from interface of cavity) Axisymmetric hydrodynamic simulations of transient jet (ZEUS-3D) (Reynolds, Heinz andamp; Begelman 2002) Cocoon described by relativistic hydro… 'inertia of pressure' important for KH and RT instabilities. Most work to date uses (matched) non-relativistic hydro

Energetics (simple axisymmetric case):

Energetics (simple axisymmetric case) Use entropy cut to separate cocoon matter andamp; ambient ICM Calculate change in gravitational, kinetic and internal energies (total injected energy ~20 units) Find an 'inflation' of the ICM due to heating and remaining bulk motions… Reynolds, Heinz andamp; Begelman (2002)

Modeling the feedback loop:

Modeling the feedback loop Direct attack on question of whether a quasi-steady state can be achieved Ingredients of the model Initially hydrostatic, spherically-symmetric ICM atmosphere described by 'beta-model' Follow hydrodynamic interaction of jet produced by central object with ZEUS-MP (half-sphere domain; 10kpc-1Mpc) Allow radiative cooling of the ICM (Sutherland andamp; Dopita 1993) In 'feedback runs', assume that jet-power is set by mass accretion rate across inner boundary of the simulation (10kpc)

Slide28:

3-d single-burst case / Density (ZEUS-MP v1.5) Vernaleo andamp; Reynolds, ApJ in press Pure cooling Single-burst jet

Slide29:

Instantaneous fueling scenario Vernaleo andamp; Reynolds, ApJ in press

Slide30:

Instantaneous fueling scenario Vernaleo andamp; Reynolds, ApJ in press

Slide31:

Delayed fueling scenario Vernaleo andamp; Reynolds, ApJ in press

Slide32:

Delayed fueling scenario with ICM rotation Vernaleo andamp; Reynolds, ApJ in press

What ingredients are missing from the feedback model?:

What ingredients are missing from the feedback model? MHD and Plasma transport processes Thermal conduction and Viscosity Dissipation of wave energy New instabilities of the ICM atmosphere AGN physics… Accretion instabilities could lead to shorter timescale intermittency Maybe jet precesses? Needs to be quasi-isotropic on cooling timescale (few108 yr) Dissipation of energy stored in global ICM modes? Evidence for dissipation of sounds waves by thermal conduction (see Fabian, Reynolds et al. 2005)

Slide34:

Absorption coefficient for linear sound waves… Absorption length-scale  and  are the viscous and thermal conduction suppression factors Fabian, Reynolds et al. (2005)

What ingredients are missing from the feedback model?:

What ingredients are missing from the feedback model? MHD and Plasma transport processes Thermal conduction and Viscosity Dissipation of wave energy New instabilities of the ICM atmosphere AGN physics… Accretion instabilities could lead to shorter timescale intermittency Maybe jet precesses? Needs to be quasi-isotropic on cooling timescale (few108 yr) Dissipation of energy stored in global ICM modes? 330-1500MHz spectral index map of Perseus (Dunn et al. 2005)

What ingredients are missing from the feedback model?:

What ingredients are missing from the feedback model? MHD and Plasma transport processes Thermal conduction and Viscosity Dissipation of wave energy New instabilities of the ICM atmosphere AGN physics… Accretion instabilities could lead to shorter timescale intermittency Maybe jet precesses? Needs to be quasi-isotropic on cooling timescale (few108 yr) Dissipation of energy stored in global ICM modes? 3C401 (Chandra and MERLIN cont.) Reynolds, Brenneman andamp; Stocke (2005) Theoretical work by Balbus andamp; Soker (1990) and Omma et al. (2003)

IV: Fueling the AGN:

IV: Fueling the AGN How is the AGN fueled? Accretion of hot ISM (Bondi-like flow)? Accretion of cold material? What is the efficiency of jet-production? How is the fueling regulated by the large scale properties of the ICM core?

Slide38:

Virgo cluster (Chandra) Jets seem to blow 'bubbles' in the ISM We can estimate power to blow a bubble if we know the pressure of the ISM M87: Power to blow cavities same as estimates for power of jets (few1044 erg/s)

Slide39:

NGC 4969

Slide40:

Chandra observations of 9 elliptical galaxies (Allen, Dunn, Fabian, Taylor andamp; Reynolds, astroph/0602549)

Slide41:

Slide42:

Compute Bondi accretion rate from the measured densities and temperatures Estimate jet power from analysis of ISM cavities Data consistent with efficient (~3-5%) conversion of Bondi flow into jet power!

Slide43:

Loewenstein et al. (2001) Seems like these SMBHs are very efficient at producing jets, not light!

Problems for radiatively-inefficient accretion flow (RIAF) theory…:

Problems for radiatively-inefficient accretion flow (RIAF) theory… Extreme lack of e/m luminosity usually attributed to disk being in advective state Such disks seem to lose most of their mass flow to outflows… Trickle of matter flowing into black hole unbinds rest of the flow Hawley, Balbus andamp; Stone (2001)

Slide45:

Hawley, Balbus andamp; Stone (2001)

The problem…:

The problem… Assuming jets derive power directly from accretion, we have… Observationally, fj0.03-0.05. Taking j0.1 implies f0.3-0.5 i.e., need substantial fraction of mass to make it to the black hole! Could be alleviated by black hole spin… Fraction of mass flow that makes it to BH Real efficiency of jet production

Conclusions:

Conclusions Several lines of evidence point to supermassive black hole feedback on massive galaxy formation Cluster cooling cores may be the on-going low-redshift manifestation of this feedback X-ray observations show obvious manifestations of radio-galaxy interaction with intracluster medium Physics behind heating andamp; feedback not clear Simplest hydrodynamic model does not distribute heating correctly Jet precession? Thermal conduction? MHD instabilities of the ICM core? Global modes? How is the AGN fueling regulated? Jet power seems simply related to Bondi accretion rate! Suggests that accretion is efficient at producing jets.

Slide48:

Croton et al. (2006)

II : Radio-galaxy feedback in clusters of galaxies:

II : Radio-galaxy feedback in clusters of galaxies Many clusters show undisputed signatures of radio-galaxy/ICM interactions Signatures ICM cavities Ghost cavities Cold filaments Shocks and compression waves Abell 4059 (Chandra) Heinz, Choi, Reynolds, Begelman (2002)

II : Radio-galaxy feedback in clusters of galaxies:

Slide52:

density T X-ray map Phase 1 (supersonic) Phase 2 (early subsonic) Phase 3 (late subsonic) Reynolds, Heinz, Begelman (2001)

Slide53:

Jones andamp; De Young (2005) O’Neill et al. (2005)