I. Outbursts from Supermassive Black Holes and their Impacts on the Hot Gas in Elliptical Galaxies II. Stripping of Hot Gas from Galaxies C. Jones, W Forman, M. Markevitch, A. Vikhlinin, E. Churazov, M. Machecek, P. Nulsen, R. Kraft, M. Sun, S. Murray, L. David, S Heinz, M. Vargas entire Chandra team Outbursts in clusters -- Perseus & M87 -- where did the gas in cooling flows go? Spectacular Shock + Plasma bubbles interacting with hot gas Outbursts in elliptical galaxies Centaurus A -- the jet, counterjet and radio lobes Interaction of the jet with the ISM Other normal exploding galaxies in Virgo -NGC4552, NGC4636, M84 A Chandra survey of ellipticals The X-ray luminosity of SMBH in normal galaxies Stripping of hot gas from galaxies - interactions of the galaxies with the ICM and galaxy-galaxy interactions Galaxies at the centers of large cooling flow systems M87 arms & arcs W. Formans talk this afternoon -- shocks and bubbles In galaxies, X-ray and radio observations allow us to probe the interactions between the central AGN, the relativistic plasma and the X-ray gas. First example - Centaurus A How do AGN jets affect gaseous coronae? Example of how cooling gas can be reheated by supersonic outflows. U Centaurus A the Nearest Radio Galaxy Kraft et al. 2000,2001,2003 Chandra VLA Centaurus A Bubbles and Jets Nearest active galaxy (3.4 Mpc; 1=17pc); Merger with gas rich galaxy 250 X-ray point sources + nucleus + jet + knots Spectacular view of an X-ray jet with opposing bubble; Chandras resolution comparable to energy-loss travel distance of X-ray emitting photons (assuming moderately relativistic bulk motions) Diffuse emission kT=0.3 keV typical for faintgalaxy Radio contours show interaction of radio plasma and origin of bubble Bubble diameter 3 kpc Multiple Outbursts in Cen A Series of outbursts seen in radio (Ekers/Burns) Nuclear jet 65 masec (5-10 yrs) Inner lobe =6x10 8 yrs Northern middle lobe Linear size to 250 kpc Repeated outbursts spanning 10 9 yrs The Jet in Centaurus A Chandra (blue) and VLA (red 8.4 GHz) observations (Hardcastle et al 2003) Jet is synchrotron emission from relativistic electrons (Feigelson et al. 1980) Faint, well-collimated inner jet region detected. In standard FRI sources, this region is where efficient, supersonic flow transports energy up to where jet flares and becomes turbulent. Could have in situ particle acceleration here. The Jet in Centaurus A Many of the X-ray knots correspond to radio knots -- in three, X-ray peaks lie closer to the nucleus than radio peaks. Ratio of X-ray to radio emission varies by more than order of magnitude Counter-jet - two X-ray knots correspond to radio knots Proper Motion of Radio Knots in Jet Comparison of 1991 and 2002 VLA observations shows features with detectable proper motion along jet. Motion ~0.06 to 0.1 in 11 years. Motion corresponds to apparent speed on sky of ~ 0.5c Most compact features show no detectable motion Hardcastle et al 2003 What are the Knots in the Jet? Weak knots in jet are not moving with jet flow, due to standing shocks with some feature that is fixed in host galaxy frame. SNRs? Need type II to get L X, but spectra are power law, not thermal. NOT SNRs. Also rule out compressions of synchrotron emitting material in jet Normal stars? Expect 10 6 in jet cone, so not normal stars. High mass stars (Wolf-Rayet) or gas clouds? (maybe too many for stars) Gas clouds - molecular gas in disk and cool (10 4 K) line emitting gas. Mass ~10 4 Msun. Jet may illuminate structure of ISM in elliptical galaxy. Why so few knots in counterjet? Differences in jet collimation? Chandra images of SW lobe with radio contours Centaurus A - Southwest Radio Lobe Model X-ray bubble as driven by expansion of radio plasma Gas temperature in lobe ~2.9 keV (in ISM kT = 0.3 keV) Enhancement width ~ 15 Shell gas density cm -3 (In ISM ~ cm -3 ) Shell overpressured ( dyn cm -2 ; in ISM ~10 -12, in lobe ~ ) Bubble expanding supersonically at Mach 8.5 (2400 km/sec) Thermal energy in shell is ergs + kinetic energy (6.5 times greater) + internal bubble energy (Thermal energy of gas within 15 kpc is ergs) Strong source of energy input to galaxy corona. Centaurus A - jet, lobes reheat ISM Chandra Recent Nuclear Outbursts powered by cooling flows NGC years years years 10 7 years NGC years years years NGC507 An Exploding Elliptical in Virgo Bright X-ray nucleus Small lobes - 1 kpc Outburst yrs ago Rims are hotter than surrounding gas (Mach 1.4 expansion) pV ~ ergs/lobe Core radio source mJy (2380 MHz) Chandra ACIS observation M89 NGC4552 NGC4552 (M89) Exploding Elliptical in Virgo Bright X-ray nucleus Small lobes - 1 kpc Outburst yrs ago Core radio source mJy (2380 MHz) Chandra ACIS observation NGC M89 Chandra Chandra smoothed image NGC4552s velocity 340 km/sec -- M87s 1300 km/sec 15 kpc tail (in plane of sky) Exploding elliptical in Virgo -- M84 Chandra image shows nucleus, bar and filaments. Lobes ~ 4 kpc diameter - outburst ~ yrs ago Interaction with radio lobes of 3C272.1 Finoguenov & Jones 2000,2001 Bubbles in a galaxy -- M84 For Perseus, M87, M84, and for almost all others gas surrounding bubble is cool No shock heating in lobe H-shaped gas has kT~ 0.6 keV Ambient gas temperature increases from 0.6 to 0.8 keV with increasing radius X-ray image; radio contours Scale 20 across bar of H. Another Exploding Elliptical -NGC4636 Strange X-ray structure in an otherwise normal Virgo elliptical galaxy Double pin wheel-like structure in X-rays! X-ray arms ~8 kpc long. Jones et al 2001 NGC4636 Small, weak radio source of about 1.4x10 38 erg/sec in core Energy injection (from nucleus) in regions east and west of galaxy center Shock travels more rapidly into lower density and forms pin wheels The energy in the outburst is ergs; occurred years ago Sharp edge and spectra confirm classic cold front kT out = 0.80 keV; kT in =0.68 keV possible high interior abundance What is the outside? Emission seen in ASCA/ROSAT to 300 kpc (1 o ) Matsushita et al (1998) Implies large mass No other bright galaxies Fossil group (OLEG; see Vikhlinin et al ) What is moving? Galaxy + small dark matter halo + gas Gas only - driven by relativistic plasma Cluster Sloshing - see Markevitch et al. Astroph NGC on larger scales A Chandra Survey of Ellipticals Two ROSAT surveys of early-type galaxies -- Beuing et al used RASS to measure X-ray emission for 293 galaxies with B T 730 km/s) collision with N4435 Conclusion: low gas temperature, small gas velocities, disturbed morphology explained by galaxy-galaxy collision as NGC4438 passed ~5 kpc south of NGC4435 with a relative velocity of 900 km s -1, ~10 8 years ago. (Machacek et al 2004) H emissionH contours on X-ray emission 3C radio source in interacting dumbbell galaxy pair. Chandra optical The Dumbell galaxy NGC4782/4783 Gas removed by ram pressure stripping? By AGN? X-ray luminosity is low ergs/sec Gas has been removed from halos - by galaxy/galaxy stripping? By AGN? Faint, extended X-ray emission around the dumbell Smoothed Chandra image Conclusions Outbursts (emission from the nucleus)ares common in early-type normal galaxies Large outbursts/high Eddington ratio (e.g. Cen A) likely result from mergers or large cooling flow. Low level X-ray emission from AGN probably fueled by accretion from surrounding gas (even in low mass galaxies). Outbursts can reheat the cooling gas through jets, shocks and bubbles Stripping of outer coronae, by ram pressure or galaxy-galaxy interactions does not appear to impact nuclear emission THANKS to Conference Organizers Temperature Map of NGC1404 Region Chandra X-ray Image Simulation by Ricker & Sarazin A true cold front Gas around NGC1404 has kT~ 1 keV Infalling into ambient gas of kT~1.5keV Caught in the act see the simulation! Extended X-ray Emission in Galaxy Nuclei NGC4649 A normal elliptical in Virgo As expected -- Hot ISM and binary X-ray sources. Chandra ACIS-S Images: 10 Chandra 3-color X-ray Image of Perseus M87 Chandra and VLA Radio (blue) and Chandra X-ray (red) The NGC4636 Model Observed parameters kT arms =1 keV; kT arm /kT ambient =1.75; n arm /n ambient =2 Shock model parameters M=1.7 (v=700 km/sec) E inj = ergs Age= years To prevent accumulation of cool gas requires outbursts every years Radio quiet outbursts, precursor to radio emission onset? Self-Regulation (see Churazov et al. 2001) Super massive black hole is at the bottom of the gravitational potential Lowest entropy gas settles to the SMBH If cooling dominates, entropy decreases, accretion rate increases, energy output from SMBH increases, input to gas increases, entropy decreases, accretion declines Cooling begins to dominate Bondi Accretion For M87 we observe M BH ~ 3 x 10 9 M sun, T~ 1keV, n e ~ 0.1 cm -3 And for Bondi accretion dM/dt = 0.01 M sun /yr, r Bondi ~ 50pc (0.6arc sec), giving a power of 7 x erg/s Twice the X-ray luminosity of the entire cooling flow region of M87 Other examples see A2052 (Blanton et al) Hydra A (McNamara et al) A2597 (McNamara et al) Centaurus A Jet Chandra images of SW lobe with radio contours Raw Chandra image of SW radio lobe with 13 cm radio contours. Adaptively smoothed Chandra image of SW radio lobe. Cen A Southwest Radio Lobe Model X-ray bubble as a bubble driven by expansion of radio plasma Gas temperature in lobe ~2.9 keV (in ISM kT = 0.3 keV) Enhancement width ~ 15 Shell gas density cm -3 (In ISM ~ cm -3 ) Shell overpressured ( dyn cm -2 ; in ISM ~10 -12, in lobe ~ ) Bubble expanding supersonically at Mach 8.5 (2400 km/sec) Thermal energy in shell is ergs + kinetic energy (6.5 times greater) + internal bubble energy (Thermal energy of gas within 15 kpc is ergs) Strong source of energy input to galaxy corona. Bubble Simulation Origin of Edges After bubble inflation (50 Myr) Bubble continues to expand and rise (buoyant) Surrounded by shell of cool gas Cooler than surroundings (since expands adiabatically) Bubble develops cap as it rises As bubble disappears, gas falls back towards cluster center and mixes Core is disturbed and 50% of energy injected into bubble is deposited in core gas (Quillis et al. 2001) What is relative importance of bubbles vs. mergers for driving sloshing in 2/3 of regular clusters? Conclusions Rich observational data base Remarkable detail; challenge to Modelling the Intergalactic and Intracluster Medium Began Chandra/XMM era in a simple world with some mergers and many cooling flows Now much more complex ICM; learn some physics about Magnetic fields Thermal conduction Formation of radio halos (see Markevitch et al. papers) M87 relative deviations Subtract smooth radial surface brightness, then divide by model 14 kpc ring - clearest example of shock-driven feature 17 kpc arc - also weak shock Eastern and southwestern arms brighten at ~14 kpc 37 kpc southern arc 1=4.5 kpc ~ 10 8 yrs ~10 7 yrs ~10 6 yrs Arms may provide a second mechanism for uplifting cool gas from the core. Radio shows arms, bubbles and a torus. Very complex radio and X-ray morphology in arms Buoyant bubbles and arms Single/Primary systems (see Jones/Forman 1999) Strong peak dense gas short cooling time Suggests no recent merging disruption; appear dynamically relaxed Have central dominant galaxy (XD) with 80% radio emission Hot gas radiates in a potential Cools & accretes If cooling time is short enough . Allen/Fabian NGC507 Bubbles and Fronts z= =28.7 kpc Eastern edge shows factor of 4 decrease in surface brightness Motion of dark matter core + optical galaxy to east or infalling gas or cold core moving Complex central emission two peaks (white) (Kraft et al. 2003) NGC507 Bubbles and Cold Fronts Peculiar double peak explained by radio source displacing gas Possible jet filling brighter lobe Brighter lobe shows evidence of compression pushing on X-ray hot gas OK radio explains peculiar double peak Just another beautiful edge/cold front? No temperature jump! XMM-Newton data show a high interior abundance approximately twice the exterior (0.5 vs. 0.25) Gas is cool so emissivity is sensitive to abundance Take a -model, and boost interior by expected emissivity of gas with twice the abundance Excellent description!! An abundance front? The Solution? NVSS radio shows . Nearly fills interior of edge Radio drives overabundant material from the center into a shell Appears as an abundance edge N507 Abundance and temperature maps Edge from complex combination of high abundance, low temperature Driven by radio bubbles/jet NGC5846 z=0.005; 1=9 kpc Clumpy shell of X-ray emission embedded in extensive group atmosphere Radio peak aligned with X-ray AGN (L x =10 39 erg/sec) Galaxy group has L x =6.5x10 41 erg/sec Radio emitting plasma drives hot gas - Radio bubble to north? Similar to ZW3146 with bubble around galaxy center expanding into hot gas NGC5846 Real structure in X-ray shell Projection through shell L clump = 2.7x10 38 erg/sec ( keV) 4 net cts Active Nucleus Clump