Recent Developments in Stellar and Planetary System Formation

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

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

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

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 Galactic 'ecology' OB *s Superbubbles => GMCs 20 - 50 Myr superbubbles inject short-lived isotopes gravity Supershells / rings

NGC 1333 IC 348 IRAS 03235+3004

M. Bate

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

Spitzer IRAC

HH 46/47 HST 1997 - 1994

HH 46/47 HST 1997 - 1994

Irradiated jets in h Car (Tr 14)

The Orion Star Forming Complex Wei-Hao Wang

Infrared view of winter sky (10 - 120 mm)

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

Orion Molecular Clouds Orion B 13 CO Orion Nebula Orion A 2. 6 mm

20

Orion below the Belt: NGC 2024 (OB 1 d) Horsehead Nebula s Orionis (OB 1 c) NGC 1981 Ori OB 1 c NGC 1977 Orion Nebula Ori OB 1 d i Ori NGC 1980: Source of m Col + AE Aur ; V ~ 150 km/s runaways, 2. 6 Myr ago

Orion Nebula Trapezium (L = 105 Lo t < 105 yr ) OMC 1 Outflow (H 2 t = 3, 000 yr) BNKL (L = 105 Lo t << 105 yr) OMC 1 -S (L = 104 Lo , t < 105 yr)

Trapezium cluster Proper motions: Van Altena et al. 88 2. 6 1. 8 Vesc ~ 6 km s-1 2. 5 5

Orion BN/KL H 2 NICFPS APO 3. 5 m First light 21 Nov 04

0. 5 – 2. 2 mm 104 AU

11. 7 mm 104 AU Gemini S TRe. CS

OMC 1 H 2 fingers

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

UV photo-ablation of disks & planet formation: d 253 -535 in M 43

Orion Nebula: Disks seen in silhouette

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

Anatomy of a planetary system forming in an OB association

Disk mass-loss: UV Radiation => heatimg = > Mass – loss t ~ 1 Myr r > GM / c 2 ~ 40 AU for Soft UV (91 < l < 200 nm) ~ 5 AU for 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 d. OB 2 Lexternal(UV) ~ 1049 photons / sec Lself(UV) ~ 1040 - 1043 photons / sec

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 – 1045 Main-sequence star Blue-supergiant Supernova Dt (g sec-1) (3 – 30 Myr) (< 106 years) (1 year) • Massive star winds, Supernovae: - Inject short-lived isotopes: 26 Al, 60 Fe

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

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

Supernovae: Oldest meteorites: (CAIs: 4, 567. 6 Myr old = 0 ) Chondrules: +2 to 4 Myr 26 Al => 26 Mg (t 1/2 ~ 0. 7 Myr) 60 Fe => stable elements (t 1/2 ~ 1. 5 Myr) => Solar System formed in Orion-like OB association SN within few pc, few Myr of forming Solar System

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 60 Fe, 26 Al, …

The End