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The Structure of AGB Winds

The Structure of AGB Winds. Moshe Elitzur (Kentucky) Ž eljko Ivezi ć (Princeton) Dejan Vinkovi ć (Kentucky). Habing, Tignon & Tielens ‘94. Once the sonic point is crossed…. Radiation pressure decouples the outflow from the wind origin Subsequent outflow Radiation pressure Gas drag

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The Structure of AGB Winds

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  1. The Structure of AGB Winds Moshe Elitzur (Kentucky) Željko Ivezić (Princeton) Dejan Vinković (Kentucky)

  2. Habing, Tignon & Tielens ‘94 Once the sonic point is crossed… • Radiation pressure decouples the outflow from the wind origin • Subsequent outflow • Radiation pressure • Gas drag • Gravity

  3. Radiation pressure • Gas drag • Gravity  Just math… Elitzur & Ivezic ‘01

  4. Solution of HTT ‘1st simplified model’ – negligible reddening

  5. Physical Domain <>F  V (1 + V)-0.36

  6. (HTT)

  7. Scaling Away from boundaries, wind structure fully controlled by 

  8. Scale of v set by Velocity Profile V < 1: k = 2/3 (drift) V > 1: k  0.4 (reddening)

  9. Radiation pressure: • v L1/2 • v independent of K. Young 1995: Miras, low : • v independent of L

  10. Lower – decoupling: • Higher – reddening: Drift + Reddening effect on v

  11. Data Same ndd/nH for C- and O-stars!

  12. Ivezic & Elitzur ’03 v = 18 SED Analysis • Shape  V • Flux level   Zubko & Elitzur ’00 v = 0.83 Solutions by DUSTYhttp://www.pa.uky.edu/~moshe/dusty/

  13.  + distance  L • L + v   , 22 W Hya

  14. AGB winds are generally spherical,PN are asymmetric. How come?

  15. IRC+10216 – the mother of all C-stars HCN J = 1 – 0 Dayal & Bieging ‘95

  16. IRC+10216 – K band Weigelt, G. et al. ‘02

  17. IRC+10216 – the bipolarity inside • Spherical at ~ 4,000 AU (molecules; Lindqvist et al ‘00) • Asymmetric at ~ 60 AU (K-band; Men'shchikov et al ’02) • V ~ 40 (equator) – 20 (poles) • ~ 10-5 Myr-1 3·10-4 Myr-1about 50 years ago

  18. IRC+30219 (CIT6) b v r Schmidt, G.D et al. ApJ (2002)

  19. CIT6 – Molecules Lindqvist et al ‘00

  20. CIT6 – the bipolarity outside? • Asymmetric at ~ 5,000 AU – both molecules and K-band (JET!) • The next phase of IRC+10216?

  21. What about O-rich stars? • IRC+10011 – the mother of all OH/IR stars

  22. IRC+10011 (CIT3)  = 1.24 m  = 1.65 m Vinković et al ‘03 Hofmann et al ‘01  = 2.12 m

  23. Successful fit of SED and 4 images (visibilities)

  24. IRC+10011 – the bipolarity inside • Spherical at K-band and beyond • Asymmetric at J-band; scale ~ 100 AU, ~ 100 yr (?) • V ~ 40 (equator) – 20 (poles) • ~ 1 – 2·10-5 Myr-1

  25. W43A – the Jets are Out! Imai et al ‘02

  26. Conclusions • The “standard model” works • Single variable – • Dust drift – major ingredient • 22 ~ 1 for both O- and C-rich; why? • AGB wind phase ends with jets • how prevalent? • time scales?

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