Lecture 10: Bubbles and PNe September 26, 2011

III. Conduction Layer - Probe the thermal conduction layer High ions produced by thermal collisions O VI N V C IV Si IV

UV Probes of the 10 5 K Gas C IV N V O VI  Å )  1548, , , 1037 Obs. HST STIS HST STIS FUSE I.P. (eV) T (K) 1.0    10 5 T eff (K) >35,000 >75,000 >125,000

Interface of the WR Bubble S308 C IV Boroson et al. 1997, ApJ, 478, 638 N V S II

S ideal for conduction study HD * R: H  G: [O III] B: X-ray Boroson et al. (1997) detected N V absorption from the conduction layer. HST STIS observation of N V and C VI emission was scheduled, but STIS died. FUSE observations of O VI were awarded, and it died, too. Spitzer can observe Ne V, but it ran out cryogen.

FUSE Observations of NGC 6543 Gruendl, Chu, Guerrero 2004, ApJL

III. Conduction Layer - Probe the thermal conduction layer High ions produced by thermal collisions - NGC 6543: given the boundary conditions of hot interior and warm shell, thermal conduction appears to be consistent, but does not explain the low X-ray luminosity. Gruendl, Chu, Guerrero 2004, ApJL

Stars and Nebulae: Evolving Together Steffen & Schönberner (2006)

Stars and Nebulae: Evolving Together Steffen & Schönberner (2006)

Interacting-Wind Model of PNe

Hot Gas in Planetary Nebulae Guerrero et al. (2005) Chu et al. (2001) Gruendl et al. (2006) NGC 2392 NGC 6543 NGC 7026 X-ray emission detected by Chandra & XMM-Newton

Hot Gas in Planetary Nebulae X-ray emission detected by Chandra & XMM-Newton T = 1-3 x 10 6 K n  100 cm x10 6 K2.7x10 6 K 1.7x10 6 K

To Ensure Detection of Diffuse X-rays 1.Closed shell or lobes to confine hot gas. 2.Stellar winds – P Cygni profiles 3.Nearby, no large extinction 4.OVI, NV lines from interface layer NGC 246, NGC no high ions, no X-rays High ions and diffuse X-rays from IC 418, NGC 2392, NGC 6826, NGC 7009

FUSE - Nebular OVI Emission NGC 7293 (Helix)NGC 6543 (Cat’s Eye) Stellar P Cygni profile  fast stellar wind Nebular O VI emission  hot gas from shocked wind O VI 1032 O VI 1037 Inside Nebula Outside Nebula Star Ly  1026

O VI of PNe detected in X-rays

O VI of PNe not detected in X-rays

Pressure-driven bubble with heat conduction at interface Bubble dynamics does not match L x (obs) / L x (expected) = to  Adjust fast wind - wind velocity - mass loss rate  Reduce heat conduction Dynamically mix nebular material (mass-loading)  

What Next? Swept-up Shell Reasonably well understood Interface (conduction) layer Spatially-resolved high-dispersion UV spectra are needed Hot interior Spatially-resolved high-resolution X-ray spectra are needed