t cool
advertisement
General Introduction to Galaxy Clusters: Scaling Relations Brian McNamara University of Waterloo Astronomical Units & Terminology 1 1 T 2 r500 3.5 Mpc 5 keV T 2 r2500 500 kpc 5 keV 1 T 2 M 500 6x1015 M 5 keV 1 2 T M 2500 2x1014 M 5 keV Kiloparsec Distance Light year Distance scaled to critical density of Universe 1000 parsecs = 3x1021 cm 3.26 parsecs Milky Way Diameter = 100,000 ly = 30 kpc 1053 erg Energy keV Temperature 1 keV = 1.16 x 107 K dynes/cm2 Pressure cluster center P=10-10 dyne/cm2 supernova explosion/GRB 10-16 Atm Why Study Galaxy Clusters? • Cosmology - evolve by gravity: dominated by dark matter, non-gravitational processes less dominant; sensitive to matter and dark energy density; scaling relations - fair sample conjecture: baryons, dark matter, baryon fraction • Galaxy formation & Evolution - closed boxes: retain byproducts of stellar evolution; history of star formation - uniform sampling in space & time - merging & perturbation: dynamical evolution of galaxies • Cosmic cooling problem - only few percent of baryons have condensed in clusters - cooling flows/feedback What is a galaxy Cluster? Abell 1689 RC =4 Richness Classes M3 + 2 0 1 2 3 4 5 QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. 30-49 50-79 80-129 130-199 200-299 300> Sizes 1-3 Mpc 300 1000 kms1 Mcl 1013 1015 M M vir 3 2 r /G 1015 h 1 M for 1000 kms 1 Galaxy Cluster at X-ray & Visual wavelengths X-ray visual 100 kpc Lx = 1043 - 1045 erg s-1 gas 101 104 cm3 kTgas m p 2 Tgas = 107 - 108 K Bremsstrahlung emissivity: ne ni Teh / kT Chandra Xray Observatory QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. E = 0.5-10 keV EA = 600 cm2 @1.5 keV FOV = 16.9x16.9 arcmin PSF = 0.5 arcsec FWHM XMM-Newton QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. E = 0.1-15 keV EA = 922 cm2 @ 1 keV FOV = 33 x 33 arcmin PSF ~ 4 arcsec FWHM Chandra’s mirrors QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Grazing incidence optics critical angle few degrees Wolter Type 1 QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. emitted spectrum observed spectrum Fe L Fe K s (E,T,Z) R(E, ) g(E,T,Z)T 1/ 2 exp(E /kT) • ionization equilibrium Normalization: EM • temperature sensitivity • metallicity sensitivity N > 8 • Z ~ 1/3 solar Arnaud 05 n n dV p e X-ray surface brighness profile Ix r3 Beta Model 3 surface brightness: Ix [1 (r /rc )] electron density: n e (r) n 0 [1 (r /rc ) 2 ]3 / 2 Multiple beta models: Ettori 2000 1 2 2/3 ratio of energy per unit mass in galaxies to that in gas Gas Temperature: depth of potential well Tx T 0.590.03 Mushhotzky 2004 Normalization agrees with high temperature simulations Low sigma clusters too hot; or sigma too low for T Mass Profiles d ln T 0 d ln r model Gitti et al. 07 M tot ( r) Abell 2390 kTr d ln d ln T Gm p d ln r d ln r 2 3 / 2 r (r) 0 1 rc kr2 3rT dT M tot ( r) Gm p r 2 rc2 dr Metallicity Distribution SN II SN Ia De Grandi & Molendi 01 element enhanced (Si, S, Ne, Mg) early enrichment z >> 0.5 Wise et al. 04 top-heavy IMF? Typcal Gas Profiles “red sequence” Gladders & Yee 05 Optical: good for finding distant clusters poor measure of cluster properties X-ray: good measure of cluster properties poor tracer beyond z ~ 1 Borgani & Guzzo 01 Gaussian density perturbations QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. 10 Mpc / a Ncl a Hierarchical clustering QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Number density of clusters: amplitude of perturbations, a Degree of clustering: m Galaxy Cluster Virgo Consortium, Springel et al. 05 Cluster Scaling Relations Simple assumptions: gravity, adiabatic compression, shocks M T 3/2 x 1 (1 z) Lx T (1 z) 2 x Implications: Lx M 4 /3 3/2 (1 z) 7/2 Same internal structure, but distant clusters denser, smaller, more luminous Observables in reverse order of difficulty: L , T , M x x Departures from scaling relations: additional physics (cooling, feedback, etc.) Evolution of scaling laws: Ettori et al. 04 examples: Lx 2V M TR R T M V M gas 1/ 2 M T 3/2 T 1/ 2 (T > 2 keV) Lx MT M T 1/ 2 1.5 Lx T 2 Simulations + Observations compare to scaling relations problems: models deal primarily with DM mass observations deal with luminous baryons simulated & observed parameters (eg. T) do not always probe same quantity Mass Function constrains m , 8 mean matter density in units of critial density, amplitude of primordial density fluctuations strategy: find observational proxies for mass Lx - easy to measure, sensitive to non-gravitational processes Tx - difficult to measure except for brightest objects M - even tougher Mass-Temperature Relation Scaling relation: M ~ T3/2 r500 M T1.5 r 2500 •small deviations from self similarity for cool clusters •normalization varies by ~30% between studies •least affected by non-gravitational physics •consistent wit self-similar evolution -Ettori et al. 04 Vikhlinin et al. 06 Ettori et al. 04 Arnaud 05 Issues: • Beta model fits • inner core • reference radius • redshift range Mass-luminosity Relation scaling relation: L~M4/3 1/ 2 slope m L M 1.590.05 intercept 4 8 Stanek et al. 06 LM p P = 1.59 +/- 0.05 Stanek et al. 06 = 1.88 +/- 0.43 Ettori et al. 04 too steep! LX (erg s-1) Luminosity-Temperature Relation 10 L ~ T2.6 5 1. preheating 2. feedback 3. cooling L ~ T2 gravity 1 3 5 T (keV) 10 Markevitch 1998 fgas fgas(r2500 -r500) Baryon fraction as cosmological probe T(keV) T(keV) assumption: universal fb f b b /m f b f gas f gal fgal ~ 0.016 f gas / f gal 10 Vikhlinin et al. 06 Ettori & Fabian 99 Ettori et al. 03 2 b 0.045h70 (from BBN & WMAP) 0.04 m b / f b 0.300.03 fgas (r2500) Constraints on m , from fgas m 0.25 0.96 Z Z assume fgas = constant f gas (1 z) 2 d(h(z)) 3A/ 2 h(z) m (1 z)3 Allen et al. Allen et al. • geometrical test • precise mass estimates over z • biases in aperture size, f constancy 2 • priors: H0, b h N(M) 1015 M m 1 m 0.3, 0.7 N(L) mass & luminosity function sensitivity to Eke et al. 92 m, Lx Mullis et al. 04 Evolution: Lx > 5x1044 erg s-1 z > 0.5 Summary • Clusters close to self-similar population (M-T) • Dark matter profile universal: theory solid • Gas scaling steeper than predicted: problem: baryon physics: cooling, heating • Cosmological parameters from clusters in concordance with SNIa, WMAP, etc. The Cosmic Cooling Problem and Galaxy Formation in Cooling Clusters B.R. McNamara University of Waterloo Cosmic Cooling Problem cooling is a runaway process fewer condensed baryons than models predict Model Predictions Observations 0.07h Balogh et al. 01 CDM hierarchy fails to account for bulge luminosities K-band luminosity function no feedback DM halo feedback Bower et al. 06 Benson et al 03 more luminous, massive halos have larger cooling times fails to explain turnover in luminosity function Rees Ostriker 77, Binney 77, White Rees 78 Cosmic Star Formation Rate Density “anti-hierarchical?” galaxy clusters Gyr Juneau et al. 2005 3 6 galaxy/SMBH formation 9 10 Bang! cD galaxies:struggle against cooling & star formation * *** *** * * ** ** * Juneau et al. 05 * * --- “Cooling flows” redshift < 0.3 (Rafferty et al. 2006) cD Galaxies are not “old, red, dead” NGC 1275 in Perseus SFR = 15 Mo yr -1 QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Conselice et al. 01 X-rays Emerging from the cool core of a galaxy cluster cD galaxy tcool~108 yr .M ~ L / T ~M ~100-1000 Mo radiative cooling losses x gas/tcool Rcool =100 kpc yr-1 .M < 10-100 Mo yr-1 spectroscopic limit spec X-ray Spectroscopy: Cooling 5-10 times less than predicted but not zero Fe XVII XMM-Newton 1999 -- Implication: Heating, feedback Peterson et al. 2003 Structure of a Cool Cluster Core Hot Atmosphere T = 108 K Ne = 10-3 cm-3 conduction 3 Mpc Starburst galaxy X-ray Cavities Cooling Region Ne = 10-2 cm-3 Rcool ~ 50-100 kpc Condensation Region tcool < 7x108 yr Rcond ~ 10 - 30 kpc 100 kpc star formation correlates central cooling time < 1 Gyr blue tcool ~7 x 108 yr Rafferty et al. 07 see also Edwards et al. 07 Star formation rate in Abell 1835 consistent with net cooling rate R-band U-band Starburst 1011 Mo of Gas SFR = 100 - 200 Mo yr-1 = Lx,spec McNamara et al. 06 Edge & Frayer 2002 Spitzer Mid-IR Starburst Spectrum of Abell 1835 de Messieres, O’Connell, McNamara, et al. in prep. Calculating Star Formation Rates Bruzual-Charlot 06 Standard cooling flow old stars cD galaxy Star formation < 50 kpc across Nebular filaments tAP < 1 Gyr MAP =108-1010 Mo cooling time (Gyr) Starburst associated with coolest keV gas kT r is the gas multiphase here? . M< 200 Mo .yr-1 tcool~tdyn r tcool = 3x108 yr ~ tSFR E ~1059 E ~ 1062 erg erg MS0735.6+7421 Perseus ghost cavity 1’= 20 QuickTime™ and a TIFF (Uncompressed) decompressor kpc are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. 1’ = 200 kpc weak shock M=1.3 shock Fabian et al. 05 McNamara et al. 05 Gitti et al. 07 Optical, radio, X-ray Gravitational Binding Energy Released by SMBH r t = r/v 20/40 cavity enthalpy thermalized in wake of rising cavity gravitational potential energy turned into kinetic energy enthalpy = internal energy+work H E pV 1 pV U MgR VgR V M V dp R Vp dR dp/dr g dE Tds pdV (therm #1) dH Tds Vdp McNamara & Nulsen 07, ARAA 0 adiabatic, radiative losses negligible H Vp Kinetic energy in wake = enthalpy lost by rising cavity Cluster Outflows: AGN Powered Starburst winds: < 1042 erg s-1 AGN outflows: . 1044 -1046 erg s-1 conduction ? Ecav,shock = 1059 - 1062 erg Mout ~ Mdisp/tcav = 1010 Mo/108 yr ~ 100 Mo yr-1 H alpha Fabian et al. 03 eg., Crawford, Hatch, & Co Blanton et al. 01 Star formation rate consistent with net cooling rate Starburst Abell 1835 1011 Mo of Gas Edge & Frayer 2002 U-band R-band E cavitycavities = 1.7 x 1060 erg cavities SFR = 100 - 200 Mo yr-1 = Lx,spec Ecavity = 1.7x1060 erg McNamara et al. 06 Pcavity = 1.4 x 1045 erg s-1 ~ Lx,cool Heating & Cooling Diagram jet power Rafferty et al. 06 Birzan et al. 04 X-ray cooling luminosity Heating-cooling Diagram for gEs All quenched! pV 4pV 16pV Nulsen et al. in prep. Heating-Cooling Diagram Bondi accretion QuickTi me™ and a TIFF ( Uncompressed) decompressor are needed to see thi s pi ctur e. Allen 06 gE & groups Quic kTime™ and a TIFF (Unc ompres sed) dec ompres sor are needed to see this pic ture. quenched “old, red, dead” cD clusters ongoing star formation cold accretion Rafferty 06 gEs from Nulsen et al. 06 QuickTi me™ and a T IFF (Uncom pressed) decom pressor are needed to see t his pict ure. Cooling rates approaching SFRs cooling Fuse mass continuity optical/UV star formation rate Rafferty et al. 06 Conditions conducive to AGN-regulated feedback loop Voigt & Fabian 04 1) tcool ~ 108 yr Rafferty et al. 06 Birzan et al. 04 2) LAGN ~ Lx Voit & Donahue 05 Donahue et al. 06 Voit 05 3) Entropy floors SMBH Specific Accretion per Event ~ doubled in mass M BH MBH / MBH Pcavity 1 1 M yr 0.1 5.67x10 45 erg s1 MBH 0.16 M yr1 (clusters) • sub-Eddington Accretion Mechanisms Bondi- only low mass systems Rafferty et al. 06 Stars - intermittent, not enough Gas - likely, but hard to regulate Black Hole Mass vs Bulge Mass Gebhardt et al. 00 Bulge Mass vs SMBH Mass SMBH mass ~ 10-3 bulge mass “Magorrian Relation” Kormendy et al. 03 Gebhardt et al. 00 Ferrarese & Merritt 00 Bulge Growth Rate vs SMBH Growth Rate Rafferty et al. 06 Abell 1835 AGN dominated Magorrian Relation Starburst dominated 10% conversion efficiency . Low Radio Frequency Traces Energy Shock M=1.34 E=9x1060 erg s-1 t=140 Myr Wise et al. 07 Radio: Lane et al. 04 74 MHz Hydra A shock 6 arcmin 1061 erg Nulsen et al. 05 Wise et al. 07 tshock= 140 Myr tbuoy= 220 Myr tbuoy > tshock 380 kpc Cluster scale heating events MS0735.7+7421 Lx E = 1/4 - 1/3 keV/baryon Excess: ~ 1 keV/baryon Others: Herc A, Hydra A Gitti et al. 07 Summary • SFRs approaching XMM/Chandra cooling rates • SFR thermostatically controlled by AGN AGN • Regulate cooling & star (galaxy) formation • Exponential turnover in galaxy luminosity function • Prevent baryon “over cooling” • Excess entropy (preheating)? Challenge: How do cavities heat, enthalpy, shocks, ?
