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Circulation Flows

Circulation Flows. Cooling flows with bubble return !. Bill Mathews (UC Santa Cruz). Fabrizio Brighenti (Bologna). David Buote (UC Irvine). X-ray Luminosity of Elliptical Galaxies. ROSAT. O’Sullivan et al. 2001. Observed SNIa rate in E galaxies SNu = 0.16 per L B = 10 10 per 100 yrs

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Circulation Flows

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  1. Circulation Flows Cooling flows with bubble return! Bill Mathews (UC Santa Cruz) Fabrizio Brighenti (Bologna) David Buote (UC Irvine)

  2. X-ray Luminosity of Elliptical Galaxies ROSAT O’Sullivan et al. 2001 Observed SNIa rate in E galaxies SNu = 0.16 per LB = 1010 per 100 yrs Is almost certainly too high (Cappellaro et al. 1999)

  3. X-ray Luminosity of Elliptical Galaxies O’Sullivan et al. 2001

  4. Range of Lx/LB determined by extent of circumgalactic gas Mathews & Brighenti 1998 Lx/LB = (rex/re)0.6

  5. Optically Dark Groups & Elliptical Galaxies NGC 5044 O’Sullivan et al. 2001 Filled circles: Optically dark galaxies/groups aka “Overluminous Elliptical Galaxies” (OLEG) “Fossil Groups” Vikhlinin et al. 1999 Ponman et al. 1994

  6. Optically Dark Groups with Mvir known from X-ray Observations NGC 6482 LB ~ Mvir may result from hierarchical assembly Several (all?) dark groups are baryonically “closed” like rich clusters: fb = Mbary/Mtot ~ 0.16 (WMAP)

  7. Warm gas in NGC 5044 -- Stellar Ejecta? stellar isophotes 6 kpc Caon et al. 2001 with crazy velocity field scale > SNIa remnants ejecta receives momentum H + [NII] very disturbed

  8. Extended Dusty Core in NGC 5044 -- Stellar Ejecta? B-I image Goudfrooij 1991 12 x 12 kpc

  9. ~50-60% of Normal Ellipticals and ~90% of Radio-Jet Ellipticals have Dusty Cores Van Dokkum & Franx 1995 Verdoes Kleijn et al. 1999 HST images

  10. Accelerated Cooling in Dusty Stellar Ejecta Cooling at 1 kpc in NGC 4472 Even dusty gas at 107 K cools very rapidly Cooled gas still contains dust Reliable minimum gas flow to black hole no dust Mathews & Brighenti 2003

  11. XMM & Chandra Observations of NGC 5044 20 kpc 150 kpc In pressure equilibrium |/|~|T/T| Scale of hot bubbles >> size of SNIa remnants Filling factor f ~ 0.5 in r < 20kpc XMM image is smooth beyond ~30 kpc Buote, Lewis, Brighenti, Mathews 2003

  12. Gas Temperature Profile in NGC 5044 1T fit to data: 2T -- a better fit to data: r (kpc) r (kpc) Multiphase temperature Tc ~T* ≤ T ≤ Th but no gas with T ≤ Tc (dM/dt)cool < 0.4 Msun /yr expected: ~5 Msun /yr Buote, Lewis, Brighenti, Mathews 2003

  13. Gas Temperature Profiles in Groups & Clusters Groups Clusters Sun et al. 2003 Allen et al. 2001 dT/dr > 0 at small radii

  14. 2T Multi-phas Emission in NGC 5044 r (kpc) r (kpc) Cool Cool phase dominates in r ≤ 30 kpc Filling factor of cool gas is f ~ 0.5 in r < 20 kpc Buote, Lewis, Brighenti, Mathews 2003

  15. Global Properties of NGC 5044 E/group ReE = 10 kpc LB,E = 4.5x1010∑LB,dwarfs = 10x1010 160 ~WMAP baryons missing iron Buote, Brighenti & Mathews 2004

  16. Global Energetics of NGC 5044 E/group Energy in cavities Ecav = PfV = 1 x 1058 erg Total SN energy Esn = 8 x 1060erg Gas binding energy Ebind = Eth = ∫thdV = 2 x 1061erg Black hole mass Mbh = 7.6x10-5 M*1.12 = 6 x108 Msun Haring & Rix 2004 Black hole energy Ebh = .1 Mbh c2 = 1 x 1062 erg to retain gas: the efficiency of black hole heating is < 0.02 power to maintain low density phase: PfV/tbuoy ~ 1043 erg/sec ~ Lx,bol = 6 x 1042 erg/sec => dMbh/dt = 4 x 10-3 Msun/yr

  17. Circulation Flows Construct flows that simultaneously move in both radial directions with no net cooling or radial mass flow: cooling inflows balanced by bubble outflows This is not convection as in stellar interiors, the S variations are more extreme Successful circulation flows: must look like cooling flows with dT/dr > 0 near center but with no cooling below ~Tvir/3 must reproduce observed iron abundance profiles to achieve this must recirculate both mass and thermal energy out from the center of the flows

  18. Simple Steady State Circulation Flows Can low-density, heated bubbles carry enough gas upstream to balance the cooling inflow mass flux? Mathews et al. 2003

  19. Simple Steady State Circulation Flow in NGC 4472 Red: cooling inflow Green: bubble outflow Steady circulation flows with no net mass flux are possible Bubbles do not heat inflowing gas very much the emission-weighted <T> profile is that of the cooling inflow; but bubbles may contribute to the X-ray spectrum Bubbles with larger mass mb require more heating at rh, but if mb is too large, there is no volume left for cool phase, f --> 0 Small bubbles move too slowly and also consume all available volume near rh, f--> 0 h = 3 rh = 5 kpc Mathews et al. 2003

  20. Radial Abundances in NGC 5044 A measure of integrated historical stellar enrichment iron silicon r (kpc) r (kpc) are central abundance dips real? large metal enhancements in r < 100 kpc much larger than stellar Re Buote, Lewis, Brighenti & Mathews 2003

  21. More XMM-Chandra Abundances in NGC 5044 silicon/iron magnesium sulfur oxygen r (kpc) r (kpc) <zSi/zFe>em = 0.83 solar => 70-80% of iron from SNIa within 100 kpc Why do O and Mg vary differently? Buote, Lewis, Brighenti & Mathews 2003

  22. XMM Iron Abundances in NGC 5044 Iron in r < 100 kpc Iron in 100 < r < 300 kpc Buote, Brighenti & Mathews 2004 zFe ~ 0.1 - 0.2 solar (where is the missing iron?) Buote, Lewis, Brighenti & Mathews 2003 Total iron mass within r = 100 kpc is ~ 108 Msunfrom all historic SNIae?

  23. Central Iron Abundance Peaks are Common in group NGC 507 in 12 CF and 10 non-CF clusters Kim & Fabbiano 2004 De Grandi et al. 2004

  24. Central Iron Abundance Peaks are Common in group NGC 507 in 12 CF and 10 non-CF clusters about 200 kpc Kim & Fabbiano 2004 De Grandi et al. 2004 “excess” iron mass in CF clusters correlates with LB of central E galaxy Excess iron mass ~ total iron from all SNIae in central E

  25. Time-dependant Cooling flows for NGC 5044 with f( r) assume fixed filling factor profile f(r ) for inflow begin with standard cooling flows for NGC 5044 with three f(r) no heating -- only radiative cooling range of flow: rh = 5 < r < re = 500 kpc calculate for 10 Gyrs result: (dM/dt)cool(rh) ~ 6 Msun/yr cooling flow is very insensitive to filling factor profile so choose constant ...profile with f(rh) = 0.5 as observed Mathews, Brighenti & Buote 2004

  26. Time-dependant Circulation flows for NGC 5044 Now assume no gas flows in past rh = 5 kpc The incoming mass flux at rh and stellar mass loss are heated by AGN and instantaneously circulated outward according to dp/dV Only the inflowing cool phase is computed Circulated gas may be heated further if h > 0 Ignore bubble drag momentum exchange Mathews, Brighenti & Buote 2004

  27. Time-dependant Circulation flows for NGC 5044 Normalized recirculation probability: parameters are (m, n, rp,kpc, <h>) Mathews, Brighenti & Buote 2004

  28. Time-dependant Circulation flows for NGC 5044 Spatially concentrated recirculation of gas without additional heating (h = 0): Dotted lines are NGC 5044 observations Flow begins at t = 2.7 Gyrs After only ~ 1 Gyr, gas near rp cools unacceptable Mathews, Brighenti & Buote 2004

  29. Time-dependant Circulation flows for NGC 5044 Spatially extended recirculation of gas without additional heating (h = 0): Flow began at t = 2.7 Gyrs Flow is shown at t = 8 Gyrs when catastrophic cooling occurred Temperature too low Density too high zFe peak too low and broad unacceptable Mathews, Brighenti & Buote 2004

  30. Time-dependant Circulation flows for NGC 5044 Flows with additional heating continue until t = 13.7 Gyrs without cooling Spatially extended recirculation of heated gas (h = 1.6 and 1.9) Luminosity of AGN in NGC 5044 is ~hLh = 4 1042 erg/s Temperature peak is reproduced Density is acceptable No gas flows into origin No gas cools Iron abundance peak from SNIae contains ~108 Msun of iron! All major attributes of 5044 are reproduced Mathews, Brighenti & Buote 2004

  31. Does the SNIa iron cool or mix into hot gas? SNIa with 1051 ergs and MFe = 0.7 Msun explodes in elliptical ISM: ne = 0.01 T = 107 equilibrium temperature profile after 5 x 104 years: Star-ISM boundary at 20 pc Diffusion zone

  32. Cooling of an Iron-rich Plasma

  33. Cooling plus Diffusion Four mixing times tm 105, 107, 2x107, 2x108 yrs zFe To avoid cooling, Fe must mix with ~5 Msun in the ISM If magnetic fields reduce the diffusion rate, the SNIa iron may cool T tcool

  34. ~60 % of Ellipticals have Dusty Cores HST images Van Dokkum & Franx 1995

  35. Heated Bubbles have Adiabatically Cooled Rims Gas adjacent to expanding bubbles is cooled by adiabatic expansion Brighenti & Mathews 2002

  36. Heated Bubbles have Adiabatically Cooled Rims Self-similar flow around spherical piston expanding into isothermal gas of decreasing density Gas temperature just beyond piston is lowered M = Mach No. at shock Brighenti & Mathews 2002

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