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You-Hua Chu Robert A. Gruendl Martín A. Guerrero Univ. of Illinois

Hot Gas in Planetary Nebulae. You-Hua Chu Robert A. Gruendl Martín A. Guerrero Univ. of Illinois. Hot Gas Expected in Interacting Winds. Fast wind is shocked to 10 7 - 10 8 K Hot gas in bubble interior 10 6 K Conduction layer 10 5 K.

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You-Hua Chu Robert A. Gruendl Martín A. Guerrero Univ. of Illinois

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  1. Hot Gas in Planetary Nebulae You-Hua Chu Robert A. Gruendl Martín A. Guerrero Univ. of Illinois

  2. Hot Gas Expected in Interacting Winds Fast wind is shocked to 107 - 108 K Hot gas in bubble interior 106 K Conduction layer 105 K

  3. Complications and Problems • Fast stellar wind - isotropic? collimated? - constant velocity? - constant mass loss rate? • Mixing with nebular gas - thermal evaporation - dynamic ablation - presence of magnetic field • Non-equilibrium ionization - abundance, temperature, mass

  4. When we can’t get potatos, we eat yams… (massive star bubbles)

  5. Interstellar and Circumstellar Bubbles Low-mass  RG, AGB  CSPN Slow wind Fast wind   Circumstellar Circumstellar nebula bubble Interstellar bubble   Slow wind Fast wind Massive   RSG, LBV  WR 

  6. Circumstellar Bubble NGC 6888

  7. Chandra X-ray Image of NGC 6888 Gruendl, Guerrero, Chu 2003, in prep. R: H G: [O III] B: X-ray

  8. Circumstellar Bubble S308

  9. XMM-Newton X-ray Image of S 308 HD 50896 * Chu et al. 2003, submitted R: H G: [O III] B: X-ray

  10. X-ray Spectra of Hot Gas in WR Bubbles NGC 6888 (Chandra) S 308 (XMM)

  11. X-ray Observations of Shocked Fast Wind • Detection of hot gas associated with fast winds • - 6 PNe, 2 WR bubbles, 2 superbubbles* • Properties of the hot gas: • Te [106 K ] Ne [cm-3 ] LX [erg/s] • PN 2-3 106 100 1031  1032 • WR 1-2 106 1 1034 • SB 8 106 0.1 1033 (* Townsley et al. 2003, ApJ, in press - Rosette & Omega)

  12. Pressure-driven bubble with heat conduction at interface  Lx (obs) / Lx (expected) = 10-1 to 10-3    • Adjust fast wind • wind velocity • mass loss rate Dynamically mix nebular material Reduce heat conduction More observations are needed.

  13. and potato skins… (105 K gas at the interface)

  14. FUSE - Nebular OVI Absorption NGC 2392 IC 418 1032 1032 1037 1037 H H Stellar P Cygni profile; nebular O VI absorption

  15. FUSE - Nebular OVI Emission NGC 7009 NGC 6543 Star Inside Outside 1032 1037 Stellar P Cygni profile; nebular O VI emission

  16. FUSE - Nebular OVI Emission NGC 3132 NGC 7293 Star 1032 1037 Inside O I O I C II No stellar P Cygni profile; No nebular O VI emission

  17. Hot gas is cool !!!

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