1. From Cloud to Cluster: A Tale of Orion Steven Stahler Eric Huff

2. T associationsopen clustersOB associations two influences: 1 low-mass outflows 2 self-gravity mostly 11 and 2mostly 2 dispersal dispersal + contraction

3. T associationsopen clustersOB associations two influences: 1 low-mass outflows 2 self-gravity mostly 11 and 2mostly 2 dispersal dispersal + contraction

4. Accelerating Contraction dissipation contraction increase as in stars shocks virial theorem

5. supported Observation: Clouds supported by turbulence. virial theorem Larson 1981

6. Idealized Model spherical, isothermal turbulent dissipation Mac Low 1999 star formation Jones & Walker 1989 Schmidt 1959 (n=1) low mass only

7. Contraction and Expansion unstable

9. Density Spike massive stars?

10. Velocity Profiles

12. Low-Mass Stars in the ONC Schmidt law

13. Conclusions Clouds supported by dissipative, turbulent pressure undergo - - accelerating contraction - accelerating star formation Schmidt law reproduces ONC low-mass star formation. Density spike provides environment for high-mass star formation.