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Infall and Outflow

Infall and Outflow. Infall and Outflow Early History: pre-1990*. David J. Wilner (CfA). *an incomplete, selective review. Dense Cores in Dark Clouds LXV: A Symposium in Honor of the 65 th Birthday of Phi Myers October 22, 2009. Historical Perspective.

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Infall and Outflow

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  1. Infall and Outflow

  2. Infall and OutflowEarly History: pre-1990* David J. Wilner (CfA) *an incomplete, selective review Dense Cores in Dark Clouds LXV: A Symposium in Honor of the 65th Birthday of Phi Myers October 22, 2009

  3. Historical Perspective Star Formation Slipher’s “Space Lines” Barnard’s Dark Clouds Bok globules, T Tauri’s Radio Molecular Lines Molecular Cloud Maps Skewed CO Lines Infall and Outflow Myers Cores: next talks 1900 -1918 1940s 1960s 1970s 1980s modern era Red Sox Champions (5x) Babe Ruth sold… Pesky hesitates Impossible Dream Fall Classic Bucky Dent Bill Buckner Curse Reversed!

  4. Radio Molecular Lines • 1960s: discoveries of OH, H2O, NH3 , H2CO • early 1970s: CO and more, but not much star formation • high mass regions too confused, dark clouds too faint • highly supersonic linewidths Goldreich & Kwan 1974 Zuckerman & Evans 1974 Arons & Max 1975

  5. Maps of Linewidths

  6. also TMC2, Ho et al. 1977 1981: “Larson’s Laws” = turbulence

  7. Skewed CO Profiles: Infall? Snell & Loren 1977

  8. infall interpretation? red/blue stats x map behavior x complexity ✓ Loren et al. 1981 Leung & Brown 1977 Phillips et al. 1981

  9. Bipolar Outflows Snell, Loren & Plambeck 1980

  10. Dense Cores: NH3

  11. Dense Cores: Outflows 0/10 “starless” 7/16 w/IRAS

  12. Outflows and Star Formation • not predicted: form a star by losing mass? • angular momentum removal • magneto-centifugal winds • outflow statistics • effectively ubiquitous • timescale = embedded phase • outflow impact • Poutflow > (MDv)core • disperses dense core • plays role in defining star mass Myers et al. 1988

  13. Inside-Out Collapse Shu 1977 • semi-analytic model • self-gravitating isothermal sphere with most unstable equilibrium • unphysical but reasonable initial condition for dense core collapse • many important extensions

  14. Stage Set for 1990s Chandler et al. 1990 • deeply embedded protostellar candidates identified, e.g. B335, and starless cores • “predictive” theory • recognition of bipolar outflows (though evolution not clear) • improving chemical understanding of dense gas tracers • bigger, more sensitive, mm-wave telescopes, esp. IRAM 30 meter • Phil’s systematic approach

  15. END

  16. Implications for Infall Obs r(r) v(r) • kinematic evidence for inside-out collapse is difficult to detect! • emerges from random motions only within few x 0.01 pc for 1 M star • tiny mass with high v • infall simultaneous with much faster outflow • short-lived phenomenon Anglada et al. 1987 Shu 1977

  17. Schematic Star Formation ARAA 1987 25, pp 23-81

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