1 / 43

John Bally

Recent Developments in Stellar and Planetary System Formation. John Bally. Center for Astrophysics and Space Astronomy Department of Astrophysical and Planetary Sciences University of Colorado, Boulder. Galaxy formation, evolution, IMF.

ziva
Download Presentation

John Bally

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Recent Developments in Stellar and Planetary System Formation John Bally Center for Astrophysics and Space Astronomy Department of Astrophysical and Planetary Sciences University of Colorado, Boulder

  2. Galaxy formation, evolution, IMF Conditions for life Star Formation Elements (He => U) Planet formation Clusters Light, K.E. of ISM black holes (AGN, stellar) • Introduction • Star Formation: • The fundamental cosmic (baryonic) process • Determines cosmic fate of normal matter

  3. Star Formation Shrink size by 107; increase density by x 1021 ! Where planets also form • Giant Molecular Cloud Core Raw material for star birth • Gravitational Collapse & Fragmentation Proto-stars, proto-binaries, proto-clusters • Rotation & Magnetic Fields Accretion disks, jets, & outflows • Planets Most may form in clusters! C. Lada

  4. OB *s  superbubbles GMCs 20 - 50 Myr   gravity Supershells / rings  Star-Formation: • SF occurs in Giant Molecular Clouds (GMCs): • Decay of turbulence + • Gravity + W + B • Collapse => disks, jets => stars, planets • Fragmentation: • Non-hierachical multiples: disintegration • Dense (mostly unbound) clusters: • < n*> ~ 103 - 105 pc -3 • 90% of stars born in OB associations: • Multiple SN • Superbubbles • => • inject short-lived • isotopes Galactic 'ecology'

  5. NGC 1333 IC 348 IRAS 03235+3004

  6. M.Bate

  7. HH 46/47 Ha, [SII], [OII]

  8. Spitzer IRAC

  9. HH 46/47 HST 1997 - 1994

  10. HH 46/47 HST 1997 - 1994

  11. Irradiated jets in h Car (Tr 14)

  12. The Orion Star Forming Complex Wei-Hao Wang

  13. Infrared view of winter sky (10 - 120 mm)

  14. The Orion/Eridanus Bubble (Ha): d=180 to 500pc; l > 300 pc Orion OB1 Association: ~40 > 8 M stars: ~20 SN in 10 Myr l Ori (< 3 Myr) 1a (8 - 12 Myr; d ~ 350 pc)) 1b (3 -6 Myr; d ~ 420 pc) 1c (2 - 6 Myr; d ~ 420 pc) 1d (<2 Myr; d ~ 460 pc) Eridanus Loop Barnards's Loop

  15. Orion Molecular Clouds 13 Orion B 2.6 mm CO Orion Nebula Orion A

  16. 20

  17. NGC 2024 (OB1 d) Horsehead Nebula s Orionis (OB 1 c) NGC 1981 NGC 1977 Orion Nebula i Ori NGC1980: Source ofm Col + AE Aur ; V ~ 150 km/s runaways, 2.6 Myr ago Orion below the Belt: Ori OB1c Ori OB1d

  18. OMC 1 Outflow (H2 t = 3,000 yr) Orion Nebula BNKL Trapezium (L = 105 Lo t << 105 yr) (L = 105 Lo t < 105 yr) OMC1-S (L = 104 Lo , t < 105 yr)

  19. Trapezium cluster Proper motions: Van Altena et al. 88 Vesc ~ 6 km s-1 2.6 1.8 2.5 5

  20. Orion BN/KL H2 NICFPS APO 3.5 m First light 21 Nov 04

  21. 104 AU 0.5 – 2.2 mm

  22. 104 AU 11.7 mm Gemini S TReCS

  23. OMC1 H2 fingers

  24. High-velocity stars: I , BN , n (Gomez et al. 2005) BN: V~ 30 km s-1 I: ~ 13 km s-1 n: ~ 20 km s-1

  25. UV photo-ablation of disks & planet formation: d253-535 in M43

  26. Orion Nebula: Disks seen in silhouette

  27. HST 16 HST 10 HST 17 Irradiated proto-planetary disks:

  28. Anatomy of a planetary system forming in an OB association

  29. Disk mass-loss: UV Radiation => heatimg = > Mass – loss t ~ 1 Myr r > GM / c2 ~ 40 AUfor Soft UV (91 < l < 200 nm) ~ 5 AUfor ionizing UV ( l < 91 nm) (for Solar mass) Self-irradiation by central star vs. External irradiation by nearby massive star: Lself(UV) / 4 p d*2 = Lexternal(UV) / 4 p dOB2 Lexternal(UV) ~ 1049 photons / sec Lself(UV) ~ 1040 - 1043 photons / sec

  30. Impacts of the environment: • Life of a massive star ~ 3 to 40 Myr • ~ planet formation time-scale • Clustering, multiplicity: • - Close-encounters • - Truncate, shock-heat disks • UV radiation: • - External + Self => Mass-lost in ~ few Myr • UV dose:1042 – 1045Dt (g sec-1) • Main-sequence star (3 – 30 Myr) • Blue-supergiant (< 106 years) • Supernova (1 year) • Massive star winds, Supernovae: • - Inject short-lived isotopes: 26Al, 60Fe

  31. UV => Fast Growth of Planetesimals: Grain growth => Solids settle to mid-plane UV => Remove dust depleted gas => High metallicity in mid-plane Gravity => Instability => 1 - 100 km planetesimals - Fast Formation of 1 to 100 km planetesimals

  32. Growing grains: Orion 114-426 (Throop et al. 2001)

  33. Supernovae: Oldest meteorites: (CAIs: 4,567.6 Myr old = 0 ) Chondrules:+2 to 4 Myr 26Al => 26 Mg (t1/2 ~ 0.7 Myr) 60Fe => stable elements (t1/2 ~ 1.5 Myr) => Solar System formed in Orion-like OB association SN within few pc, few Myr of forming Solar System

  34. Conclusions • Most stars form in Orion-like regions • - Sibling star interactions • - Jets => halt star formation • Proto-planetary disks processed by UV • - Gas lost in few x 106 years • - Grain growth + sedimantation + UV • => Prompt planetesimal formation • Massive Stars: • - Mutual interactions => high velocity stars (BN) • => explosive outflows • - HII regions => halt star formation • - Supernavae: • => Inject 60Fe, 26Al, …

  35. TheEnd

More Related