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Forward. 1987 , Whistler: first time I met Malcolm 1989-1991 , post-doc at MPIfR: study of molecular gas in UC HII regions (NH 3 , C 34 S, CH 3 CN) with 100m and 30m tel.  pc-scale clumps and strong, optically thick emission

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  1. Forward • 1987, Whistler: first time I met Malcolm • 1989-1991, post-doc at MPIfR: study of molecular gas in UC HII regions (NH3, C34S, CH3CN) with 100m and 30m tel.  pc-scale clumps and strong, optically thick emission • 1992-…, Arcetri (with Malcolm): NH3, CH3CN observations with VLA & PdBI  0.1 pc HMCs, cradles of OB stars • 1994-…, younger phase??? Luminous IRAS sources, with H2O maser but w/o UCHII

  2. IRAS 20126+4104: the story • 1994: 30-m survey of IRAS sources with H2O maser: 13CO, CS, C34S, CH3OH, HCO+, HCN, CH3CN  dense clumps and outflows • 1995: PdBI follow up of ‘‘wisely’’ chosen source: IRAS 20126+4104 DC config., 4 antennas, only 3mm RX: HCO+(1-0); CH3CN(5-4) v=0,1; CH313CN(5-4)

  3. IRAS 20126+4104: the story • 1994: 30-m survey of IRAS sources with H2O maser: 13CO, CS, C34S, CH3OH, HCO+, HCN, CH3CN  dense clumps and outflows • 1995: PdBI follow up of ‘‘wisely’’ chosen source: IRAS 20126+4104 DC config., 4 antennas, only 3mm RX HCO+(1-0); CH3CN(5-4) v=0,1; CH313CN(5-4)

  4. Results • HCO+bipolar outflow • different orientation wrt Wilking et al. (1990) • blue- & red-shifted in both lobes • CH3CN  rotating disk (?) • velocity gradient perpendicular to outflow • NIR  H2 jet; embedded cluster Open questions • CO & HCO+: one or two outflows? • CH3CN: rotation or expansion?

  5. Wilking et al. (1990) blue-shifted red-shifted

  6. HCO+(1-0) high-velocity low-velocity

  7. Results • HCO+bipolar outflow • different orientation wrt Wilking et al. (1990) • blue- & red-shifted in both lobes • CH3CN  rotating disk (?) • velocity gradient perpendicular to outflow • NIR  H2 jet; embedded cluster Open questions • CO & HCO+: one or two outflows? • CH3CN: rotation or expansion?

  8. outflow axis 3 arcsec resolution

  9. Results • HCO+bipolar outflow • different orientation wrt Wilking et al. (1990) • blue- & red-shifted in both lobes • CH3CN  rotating disk (?) • velocity gradient perpendicular to outflow • NIR  H2jet; embedded cluster Open questions • CO & HCO+: one or two outflows? • CH3CN: rotation or expansion?

  10. Results • HCO+bipolar outflow • different orientation wrt Wilking et al. (1990) • blue- & red-shifted in both lobes • CH3CN  rotating disk (?) • velocity gradient perpendicular to outflow • NIR  H2jet; embedded cluster Open questions • CO & HCO+: one or two outflows? • CH3CN: rotation or expansion?

  11. (?)

  12. 1997: PdBI AB config., 5 antennas, 3mm & 1mm H13CO+(1-0); SiO(2-1); CH3CN & CH313CN(12-11) Results • SiO bipolar jet • consistentwith H2 jet and HCO+ bipolar outflow at high vel. • expanding at 100 km/s • CH3CN  rotating accretion(?) disk • Malcolm’s insight: line width suggests Keplerian rotation! • peak velocity suggestive of infall Open questions • SiO & HCO+: why is low velocity emission different? • What is the mass of the (proto)star?

  13. high-velocity low-velocity

  14. high-velocity low-velocity

  15. Inclination=9° Opening ang.=21° Vexp=100 km/s (R/Rmax)

  16. 1997: PdBI AB config., 5 antennas, 3mm & 1mm H13CO+(1-0); SiO(2-1); CH3CN & CH313CN(12-11) Results • SiO bipolar jet • consistentwith H2 jet and HCO+ bipolar outflow at high vel. • expanding at 100 km/s • CH3CN  rotating accretion(?) disk • Malcolm’s insight: line width suggests Keplerian rotation! • peak velocity suggestive of infall Open questions • SiO & HCO+: why is low velocity emission different? • What is the mass of the (proto)star?

  17. jet disk 0.7 arcsec resolution

  18. Malcolm’s insight: FWHM R-0.5 Keplerian rotation

  19. systemic velocity FWHM R-0.5 Keplerian rotation

  20. dMacc/dt = 10-3 MO/yr

  21. 1997: PdBI AB config., 5 antennas, 3mm & 1mm H13CO+(1-0); SiO(2-1); CH3CN & CH313CN(12-11) Results • SiO bipolar jet • consistentwith H2 jet and HCO+ bipolar outflow at high vel. • expanding at 100 km/s • CH3CN  rotating accretion(?) disk • Malcolm’s insight: line width suggests Keplerian rotation! • peak velocity suggestive of infall Open questions • SiO & HCO+: why is low velocity emission different? • What is the mass of the (proto)star?

  22. In the meanwhile… • Zhang et al. (1998, 1999): NH3 with VLA Keplerian disk (20 MOstar); low-velocity NH3 in SiO jet • Hofner et al. (1999): 3.6 cm cont. with VLA thermal jet of 1000 AU • Moscadelli et al.(2000): H2O maser with VLBA conical jet over < 300 AU • Shepherd et al. (2000): 12CO(1-0) with OVRO precessionof jet/outflow

  23. 2002: PdBI BC config., 6 antennas, 3mm & 1mm C34S(2-1) & (5-4); CH3OH(2-1) v=0,1 & (5-4) v=1 Results • CH3OH bipolar jet • similar to HCO+low-velocity bipolar outflow • precession explains difference between HV and LV flow • C34S disk • Keplerian rotation about 7 MO star • pseudo-Keplerian rotation on larger scales mimics more massive star • temperature & density gradient in disk

  24. IRAS 20126+4104 jet in H2 line H2 knots

  25. Lebròn et al. (2006) IRAS 20126+4104 Cesaroni et al. (2005) Precession model: opening angle=37° Vexp=100 km/s 360°/20000 yr

  26. Precession explains difference between high- and low-velocity HCO+(1-0) emission!

  27. 2002: PdBI BC config., 6 antennas, 3mm & 1mm C34S(2-1) & (5-4); CH3OH(2-1) v=0,1 & (5-4) v=1 Results • CH3OH bipolar jet • similar to HCO+low-velocity bipolar outflow • precession explains difference between HV and LV flow • C34S disk • Keplerian rotation about 7 MO star • pseudo-Keplerian rotation on larger scales mimics moremassive star • temperature & density gradient in disk

  28. IRAS 20126+4104 Cesaroni et al. Hofner et al. Moscadelli et al. Keplerian rotation: M*=7 MO Moscadelli et al. (2005)

  29. More and more studies… • Edris et al. (2005): CH3OH & OH with Merlin Keplerian rotation (< 20 MOstar) • Sridharan et al. (2005): K, L’, M’ with UKIRT disk and binary system (850 AU separation) • Trinidad et al. (2005): H2O & 1.3cm with VLA rotation of H2O maser jet? • Lebròn et al. (2006): 12CO(2-1) with 30m precessionof outflow

  30. IRAS 20126+4104: the picture • Clump: 1 pc, 400 MO, 40 K • Outflow/jet: < 0.5 pc, > 64000 yr, 100 km/s, 8 10-4 MO/yr, precession every 20000 yr • Keplerian disk: 4 MO, 1500 AU, 150 K, > 108 cm-3, T & nH2 gradient, accretion(?) at 10-3 MO/yr • (proto)star: 7+/-2 MO, 104 LO Best example of circumstellar accretion disk in high-mass (proto)star important implications on high-mass star formation

  31. IRAS 20126+4104: the never-ending story • Is the distance 1.7 kpc??? • Is the clump counter-rotating??? • parallax of 44 GHz CH3OH masers • merging of C34S Pico Veleta with PdBI • SiO velocity in precessing jet, H2O maser VLBI monitoring, high resolution & sensitivity PdBI imaging of CH3CN disk, etc. etc.…

  32. IRAS 20126+4104: the never-ending story • Is the distance 1.7 kpc??? • Is the clump counter-rotating??? • parallax of 44 GHz CH3OH masers • merging of C34S Pico Veleta with PdBI • SiO velocity in precessing jet, H2O maser VLBI monitoring, high resolution & sensitivity PdBI imaging of CH3CN disk, etc. etc.…

  33. Still a lot to understand… Malcolm’s tips urgently needed!

  34. close to star: T > 300 K far from star: T < 200 K

  35. Zhang et al. (1998) Keplerian rotation about 20 MO star

  36. Shepherd et al. (2000) H2 knots

  37. disk Yao et al. (2000) Sridharan et al. (2005)

  38. Sridharan et al. (2005)

  39. SiO HV H2 NH3 LV cm HCO+ H2O CH3OH LV CO(7-6) jet/outflow structure

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