The Challenges of the Last Decade of Observations of PNe

1. The Challenges of the LastDecade of Observations of PNe Bruce Balick University of Washington HST image by Hans Van Winckel, and Martin Cohen Model by Vincent Icke Gdansk June, 2005

2. The Challenges of the LastDecade of Observations of PNe • Introduction: In the past decade HST, Spitzer, and many other new tools have opened new ranges of spectral coverage and, at the same time, pushed the imaging observations to the milliarcsec domain. • Data: Observational progress has been dizzying. • Most theoreticians are just starting to recover. • Conclusion: The endpoint of stellar evolution is the startpoint for uncovering significant new insights into late stages of stellar evolution. Gdansk June, 2005

3. H-R Diagram, 1 Msun

4. 1 solar mass, no rotation Inter-pulse Period = 105 y Sackman, Boothroyd & Kraemer 1993 Astrophysical Journal 417 473

5. Betelgeuse - Ascending the “AGB”; preparing to eject a protoPN

6. RoundPNefrom Isotropic WindsKwok, Purton, & Fitzgerald 1978; Dyson, Pik’elner…

7. Challenge: If winds are Isotropic then why aren’t all PNe round? • do almost all dying • AGB/post AGB stars • build collimators? • How? • <20% are round. The other symmetries of PNe fall into clear patterns and categories. Gdansk June, 2005

8. Challenge. What paradigm? • GISW models were generally successful in explaining the large-scale features of most PNe.

9. HST upended our complacency Cat’s Eye NGC 6543 1” seeing [N II] [O III] Gdansk June, 2005

10. The devil is in the details… FLIERs Jets Paradigm lost?

11. Challenge: Why are many outflows stunningly collimated, esp pPNe? • where there’s collimation, there must be collimators Kwok, Hrivnak, Su et al

12. Q: Challenge: How do dying stars make disks without accretion?A: Mass-transfer binaries?Q: Challenge: Can accretion do it alone? What’s the collimator?A: At best, a thick disk. Challenge: The disks are too thin! He 3-1475 He 3-401 He 2-90 CRL 618

13. Challenge: Too Many Axes, Not Enough Disks Sahai & Trauger 1998

14. CRL 2688 7 pairs! Red = H2 2.12 mm Blue = scattered starlight Contours = 12 CO Cox et al 2002 Kastner et al 2001 blueshifted redshifted

15. Challenge: CO studies of outflowsshow HUGE momentum excess! • Bujarrabal, Alcolea, and their collaborators: radiation-driven winds aren’t a complete answer > gravitational powering by close binaries?

16. Ellipticals with Attitude:soft X rays fill the bubble BD+30˚3639 NGC 7009 NGC 6543

17. Challenge: Changing Wind Mode? NGC 6543 Corradi et al 2004

18. Challenge: “Hubble Flows” OH 231.8+4.2Alcolea et al. (2001) A&A 373,932

19. He2–104 Result: ages ≈ 5700 yr Corradi et al 2002

20. Menzel 3Santander et al 2004 275 km s-1 Bottom line: all major components have nearly the same expansion ages.

21. Challenge: Steady Winds or Eruptions? Physics of “Hubble” outflows: • sudden ejection + ballistic flow? • self similar? (adiabatic?) • magnetic “event” (see Frank talk) • What processes orchestrate the spectacular grand finale at the AGB tip? • Whither all that outflow momentum?

22. Magnetized Wind Collimation Model Isodensity surfaces Steady magnetized wind carrying dipolar field. Stellar rotation • flings equatorial fields and creates a (passive) disk • winds polar fields and traps high-latitude winds Steady state solution; can’t make Hubble flow Magnetic “bomb” next. IRAS 17106-3046 Kwok et al. 2000 h Carinae Morse et al. 1998

23. Grand Challenge: What creates and shapes PNe? Astronomy: How do stars create high-order symmetries in a brief event? • Internal? Thermonuclear pulse? Symmetry imposed by emerging B fields? • External? Sudden CE phase or tidal onset? • What generates plural symmetry axes?

24. Applause

25. M2-9: 40 years of mischief

26. M2–9 HST motion picture

27. Common Envelope Collimator? Colors: Outflow Velocity Field Wire Frame: Isodensity Surface F. Garcia, A.Frank, N. Soker, B. Balick, in progress

28. Early MHD Simulation Mz 3 Image Heuristic Model Magnetic fields, sudden Ionization & heating, steady winds Model V, Garcia-Segura et al 1999 Astrophys J, 517, 767

29. Magnetic “Bomb”: sudden emergence of surface B fieldsFrank, Matt & Balick (in progress) ?? Some “al” #’s: Thompson, Hines, & Sahai (1997) If we assume: Mcore = 0.5 Msun Vesc = 1000 km/s MEgg ≈ 0.062 Msun(Bujarrabal et al. 2001) REgg ≈ 104 AU Then: Rcore ≈ 0.2 Rsun Bcore ≈ 105 Gauss KEcore ≈ 1046 erg Tspin-down ≈ 100 years

30. Whither the fields? Hd+HeII Hg+HeII HeII 4686 Hb+HeII NGC 1360 stellar circular polarization and models for 2832G (-1343, 1708, 2832, 194 G; 4 obs/42 days) LS1362 Abell 36? EGB 5? “Discovery of Magnetic Fields in CPNs” Jordan, Werner, O’Toole, ASP Conf Ser (LANL Prerprints) ESO-VLT1 + FORS1

31. Wherefore the fields? … we show that an asymptotic-giant-branch (AGB) star can indeed generate a strong magnetic field, having as its origin a dynamo at the interface between the rapidly rotating core and the more slowly rotating envelope of the star. The fields are strong enough to shape the bipolar outflows that produce the observed bipolar planetary nebulae. “Dynamos in AGB stars as the origin of magnetic fields shaping planetary nebulae” E.G. Blackman, A. Frank, J.A. Markiel, J.H. Thomas, H.M. van Horn Nature, 409, 485-487 (25 January 2001)

32. Wherefore the fields? Numerical simulations of the shape of the magnetic field lines in a magnetic star. Field lines protruding through the surface of the star (red) are held together and stabilized by the twisted ring inside the star (blue). This magnetic field configuration drifts slowly outward (over a period of hundreds of millions of years) under the influence of the finite electrical resistivity of the star, then distorts into the shape of the seam on a tennis ball. “A fossil origin for the magnetic field in A-stars and white dwarfs” J. Braithwaite and H.C. Spruit Nature, 431, 819-821 (14 October 2004)