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01Dec2006 The Big Picture Ge/Ay133 Review/ 0.05-5 AU region. - PDF document

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01Dec2006 The Big Picture Ge/Ay133 Review/ 0.05-5 AU region. Jovian planets througout the And No strong preference for orbital distances except for a pile up of hot Jupiters at P~3 days. Why do we care about gas

  1. 01Dec2006 “The Big Picture’’ Ge/Ay133 Review/

  2. 0.05-5 AU region. Jovian planets througout the And…

  3. No strong preference for orbital distances… …except for a “pile up” of hot Jupiters at P~3 days.

  4. Why do we care about gas & ice in disks? Disk-star- and Theory protoplanet interactions lead to migration while the gas is present . Core- accretion & ice? 1 AU at 140 pc subtends 0."007. Jupiter (5 AU): V doppler = 13 m/s Simulation G. Bryden (JPL) V orbit = 13 km/s Observation?

  5. Characterizing large disk samples? SED Models: HH 30 G.J. van Zadelhoff 2002 Chiang & Goldreich 1997 IR disk surface within several 0.1 – several tens of AU (sub)mm disk surface at large radii, disk interior.

  6. Statistically, how long do gas/dust rich disks “survive”? Basic result: Disks dissipate within a few Myr, but with a large disp. for any SINGLE system. When they go, however, the dissipation is FAST in comparison w/ disk “lifetime.”

  7. Putting it all together: A comparison of various disk dispersal mechanisms The stellar encounter (SE) and external photo- evaporation time scales are calculated for the core of the Orion proto- stellar cluster. Hollenbach et al. (2000, PP IV)

  8. Did the Sun form as part of a rich cluster?

  9. One important set of clues: Short-lived nuclides in meteorites Murchison CAIs terrestrial terrestrial Thin section (chondrules)

  10. How do we tie astronomy & meteorite timescales together?

  11. How do disks evolve, REALLY?

  12. This? Or this? Turbulent disks & stochastic migration.

  13. Look at time to open a gap as compared to the viscous response time scale of the disk gas. Find: Planet mass needed to open gap:

  15. CO Good Dynamical, Temp. Tracer Dent et al. 2005, JCMT T MB (K) v LSR (km/s) The CO line shape is Sensitive to: R disk , M star, Inc. These can be measured M. Simon et al. w/resolved images: 2001, PdBI

  16. Disk chemistry? Depending on dust opacity, cores may spend a long time in the “plateau” phase before runaway gas accretion. Form cores closely spaced in higher density region. Need spatially resolved measurements of disk gas & its composition.

  17. Enter ALMA: Dust simulation (L.G. Mundy), realistic phase errors, but no CLEAN/MEM. Superb site & large array exceptional performance (50 12m telescopes, by 2012). Llano de Chajnantor; 5000 m, good for astronomy, tough for humans!

  18. When rings are seen around >10 Myr old stars… the dust must be made in place. • CSO/HST have reached similar conclusions about structure of the disk around Fomalhaut and how it is generated. Is there a planet required to maintain it? Kalas, Graham, & Clampin – Marsh et al. – ApJ, Feb. 2005 HST, Nature, June 2005

  19. The future: discovery space for indirect methods… Radial velocity Astrometry

  20. HD 149026 Transiting systems rare but incredibly informative…

  21. … and photometry from space can be extremely good! Brown, T.M. et al. 2001, ApJ, 552, 699 HD 209458 - HST The KEPLER mission is dedicated to photometry and can search for earth mass planets in the so- www.kepler.arc.nasa.gov called habitable zone via transits.

  26. IDPs can be analyzed in the lab! Comet dust assembled from sub- micron sized components.

  27. provenance! Samples of known

  28. 1999 KR 16 First (non-Pluto) trans-Neptunian object found in 1992 (Jewitt & Luu), now many many hundreds. They are found through their motion on the sky, gives R, i fairly quickly.

  29. Plutinos 3:2 2:1 g n i s s o r c e n u t p e N scattered KBOs classical KBOs

  30. What can meteorites tell us about the early S.S.?

  32. These irons and pallasites likely originate in the cores or core-mantle boundaries of differentiated bodies.

  34. Equilibrium Gas Abundances in Silicate Magmas SiO 2 + 2Fe 3 O 4 → 3Fe 2 SiO 4 + 0 2 SiO 2 + 2Fe + O 2 → Fe 2 SiO 4 The atmosphere is also strongly affected by core formation, and its timing.

  35. The future: discovery space for indirect methods… Radial velocity Astrometry

  36. Finding other Earths? The Space Interferometry Mission (SIM)

  37. If we locate other Earths, how might we then characterize them in detail? TPF-I TPF-C

  38. Nulling: Use the fringes to suppress the central star. First tests w/ Keck in 2006. TPF?...

  39. What can remote sensing of atmospheres tell us?

  40. What would be possible with TPF as presently envisioned? About R ≈ 100 even in the very best set of circumstances. What might you want?

  41. Coupled evolution of the biosphere and atmosphere:

  42. R ≈ 1000 needed to distinguish abiotic and prebiotic earth

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