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Tatsuhiko Hasegawa (ASIAA) 2010 February ALMA-T Users Workshop

Tatsuhiko Hasegawa (ASIAA) 2010 February ALMA-T Users Workshop. Quantitative Characterization of Tori in Evolved Stars – A possible observational project on evolved stars with ALMA. Summary An evolution scenario for (post-)AGB stars and (pre-)planetary nebulae

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Tatsuhiko Hasegawa (ASIAA) 2010 February ALMA-T Users Workshop

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  1. Tatsuhiko Hasegawa (ASIAA) 2010 February ALMA-T Users Workshop Quantitative Characterization of Tori in Evolved Stars – A possible observational project on evolved stars with ALMA

  2. Summary • An evolution scenario for (post-)AGB stars and (pre-)planetary nebulae • Evidence of torus and jet developments at the end of AGB phase. • Difficulties for quantitative descriptions of the torus developments. • Straw man target list. Observing line. • Detection feasibility of expanding tori. Demonstrations of detections with SMA. • Dynamical times of tori and jets – This is the best we have. We need more points with better angular resolutions. • List of theoretical explanations.

  3. Summary • Resolving the torus structures in 20 – 30 (post-)AGB stars and (pre-)planetary nebulae in the CO(2-1 or 3-2) line with a 0.1 – 0.01 arcsecond resolution with ALMA to determine the basic physical parameters of the tori [R_in, R_out, h_z, V(expansion), M(torus), dynamical time ]. • Quantitatively describing the formation and evolution of the torus structures in the evolved stars from the sample. Taking a census of deviations from the axial symmetry and radial expansion of the torus-like structures. How common are the tori among the evolved stars ? • Providing constraints to the theorists.

  4. Fong et al. 2006 (ApJ, 652, 1626) – Evolved stars, Pre-planetary nebulae, and Planetary nebulae in HR diagram

  5. M* (main seq) = 0.8 – 8 M_sun H+, C+, O+ Evolved Planetary Nebula V(expansion) ~ 15 km/s CO, H2 AGB phase (Mira variables) C/O > 1 (carbon stars) C/O < 1 (M type stars) C/O ~ 1 (S stars) Young Planetary Nebula H+, C+, O+ Pre-Planetary Nebula CO, H2 CO, H2 HI, C+, OI CO, H2

  6. Glassgold 1996, ARAA, 34, 241. Omont 1991, NATO ASI, p171. d = 200 pc case Interstellar UV radiation Circumstellar Envelope 10 K Tk =500 K 1'' Transition Zone 2000 K Vexp = 15 km/s Photosphere Vexp R* = 2.5 AU R1 = 250 AU R2 = 20,000 AU = 0.1 pc

  7. Planetary Nebula NGC 6302 HST image 30’’

  8. Planetary Nebula NGC 7027 • Central star • HII region ( R = 5” ) • Molecules (CO, R = 35” ) • Dust

  9. Zhang & Kwok 1998 ApJS, 117, 341

  10. Fong et al. (2006) BIMA CO(1-0) vs HST and mid-IR IRAS 17106 –3046 Kwok et al. 2000 (ApJ, 544, L149)

  11. Provisional list of evolved stars for a torus survey with ALMA O-rich stars D (pc)C-rich stars D (pc) R Dor 70 IRC +10216 130 pc HD 179821 5.6 kpc CIT 6 380 pc IRC +10011 510 ? Y Cvn 300 pc RW Lmi 390 pc RX Boo 160 22272+5435? 1.7 kpc R Leo 114 17106–3046 TX Cam 330 07134+1005 (SMA obs) I K Tau 250 23166+1655 VY CMa 1500 04296+3429 VX Sgr 410 17150–3224 NML Cyg 3400 ? 17441–2411 Mira 130 20000+3239 HD 161796? 1 kpc TT Cyg 510 89 Her 1 kpc CL Mon 770

  12. RA DEC DEC RA –10 km/s channel map 0 km/s channel map +10 km/s channel map Velocity Velocity RA RA RA Velocity Velocity RA RA

  13. NGC 7027. HCO+(3–2). SMA. Huang et al. (2010, submitted)

  14. p Gruis CO(2–1) SMA Chiu et al. 2007 ApJ, 645, 605

  15. Torus ejection period Jet launch SMA SMA Huggins 2007, ApJ, 663, 342

  16. TABLE 2 Jet-Torus Scenarios (Huggins 2007, ApJ, 663, 342) Magnetic wind from single star ……………………… Jets and torus ? Primary mass loss + companion accretion disk O Discrete torus ejection ? Companion accretion disk + CE ejection ………………… Wrong sequence Common Envelope ejection + magnetic polar wind O Jet lag ? (Common Env.) magnetic polar + equatorial explosion O Jet lag ? (CE) primary accretion disk + late nebula ejection ……… Wrong sequence Common Env. partial ejection + primary accretion disk O Jet lag ? CE ejection + post-CE primary accretion disk (RLOF) ....... Timescale too long ?

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