1. Magnetic Channeling and Confinement in the Hypersonic Winds of Massive, Luminous Stars Rich Townsend University of Delaware Stan Owocki Asif ud-Doula Mary Oksala David Cohen Marc Gagné Steve Skinner ESO Chile ̶ November 2006

2. Overview - σ Ori E - θ 1 Ori C

3. Luminous

4. Radiation-driven wind

5. CNO cycle

6. Convective core

7. Radiative envelope

8. 197820022005 No magnetic field * ?

9. Plasma PhysicsStellar Evolution Compact Objects Circumstellar Environment

10. θ 1 Orionis C

11. Feigelson et al. (2002) θ Ori - Chandra ACIS-S - θ 1 Ori C (O5.5)

12. Wojdowski & Schulz (2005) 10 7 K / 1 keV / 1,000 km s -1 θ 1 Ori C ζ Pup

13. Babel & Montmerle (1997) M agnetically C onfined W ind S hock

14. ud-Doula & Owocki (unpub.) ZEUS - Density

15. ud-Doula & Owocki (unpub.) ZEUS - Temperature

16. Gagné et al. (2005) 10 7 K / 1 keV / 1,000 km s -1

17. ZEUS - DensityZEUS - Temperature ud-Doula & Owocki (unpub.)

18. Magnetic Confinement η = B 2 /8π / ρv 2 /2 η = [B * R * /Mv ∞ ] (r/R * ) 22 -4. η*η* r A /R * = η * 1/4

19. ZEUS - DensityZEUS - Temperature ud-Doula & Owocki (unpub.)

20. ! Field Strength Rotation Rate Mass-Loss Rate

21. σ Orionis E

22. Skinner et al. (2004) - σ Ori AB (O9.5 + B0.5) - σ Ori E (B2) σ Ori D (B2) - σ Ori - Chandra ACIS-S

23. σ Ori AB σ Ori E 10 7 K / 1 keV / 1,000 km s -1 Skinner et al. (2004) σ Ori - Chandra ACIS-S

24. Hesser et al. (1977) Landstreet & Borra (1978) Bohlender et al. (1987)

25. Kaufer et al. (1999)

26. “ two more or less isolated clouds … near the intersection of the magnetic and rotational equator ” Groote & Hunger (1982)

27. Field lines are almost rigid

29. R igidly R otating M agnetosphere Townsend & Owocki (2005)

33. Townsend, Owocki & Groote (2005)

35. Townsend, Owocki & ud-Doula (in prep.) Rigid Field Hydrodynamics

36. Townsend, Owocki & ud-Doula (in prep.)

38. Summary New approaches for modeling magnetic confinement in massive stars –MHD –RRM –RF-HD Rewarding success in reproducing optical & X-ray properties

39. Ongoing & Future Work Confrontation between RF-HD and UV, X- ray (& interferometric) observations Hybrid RF-HD/MHD models to simulate centrifugal breakout Laboratories for understanding magnetic- radiation-rotation interaction Synergies with other classes of magnetic object – Polar, AB Dor, Magnetar

40. http://shayol.bartol.udel.edu/massivewiki/

41. Sanz-Forcada et al. (2004)

42. C entrifugal B reakout ud-Doula, Townsend & Owocki (2006) ZEUS - Density

43. ud-Doula, Townsend & Owocki (2006) ZEUS - Temperature