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Exo-planets: ground-based How common are giant planets? What is the distribution of their orbits? –3.6m HARPS: long-term radial velocity monitoring of.

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Presentation on theme: "Exo-planets: ground-based How common are giant planets? What is the distribution of their orbits? –3.6m HARPS: long-term radial velocity monitoring of."— Presentation transcript:

1 Exo-planets: ground-based How common are giant planets? What is the distribution of their orbits? –3.6m HARPS: long-term radial velocity monitoring of large samples to 1 m/s => Saturns out to ~5 AU –VLT-AO/OWL: Direct imaging of giant planets; complement to JWST NIRCAM/MIRI direct detection –VLTI (10  as)/ALMA (100  as): astrometry => >10 M Earth out to large AU; complement to GAIA, which can observe much larger sample but for shorter period Ewine van Dishoeck, ESO-ESA coordination meeting, September 15 2003, Garcching

2 Planetary search methods Perryman 2000

3 Planetary search methods Perryman 2000 - HARPS 1 m/s => > Saturn out to 5 AU with 10 yr monitoring - VLTI 10 mas => > 10 M Earth in terrestrial planet forming zone

4 Giant planets (cont’d) How do giant planets affect terrestrial planet formation? Inward migration, ejection of remnant planetesimals, pumping up of i,e –Link ground-based giant planet systems with space-based searches for Earth-like planets? Free-floating/isolated exo-planets and brown dwarfs => formation from disk or fragmenting cloud? –VLT/JWST searches in/near star-forming regions (younger objects have larger luminosities)

5 Giant planets (cont’d) Planetary atmospheres: composition => thermal properties, mass, age –VLT, OWL => high-res spectra; complements JWST NIR, MIRI spectrophotometry and low-res spectra

6 Ground-based spectrum of nearest T dwarf Scholz et al. 2003 Need space to observe critical H 2 O and CH 4 bands

7 Model exo-planetary atmospheres Note change in mid-infrared spectral features with age Based on Burrows et al. 1997

8 Exo-earths with OWL Sun is ~10 10 times brighter than Earth at VIS –concentrate light as much as possible –make separation as large as possible  both D and Strehl must be very large OWL would see –Earth-like planets in HZ out to 30pc –cold Jupiters out to Pleiades (120pc) and beyond –hot Jupiters further out (but resolution)  D=100m just enough for this (sensitivity  D 4 ! ) Spectroscopy –Exo-biospheres? Gilmozzi 2003

9 Solar system @10 pc Jupiter @5AU Earth @1AU OWL 100m J Band 80% Strehl 10 4 sec 0.4’’ seeing O.1’’ Gilmozzi 2003

10 The answer lies in the past, during the time when the star and its planets are being assembled Simulation G. Bryden Why are exo-planetary systems different from our own? Theory Need spatially resolved images at mid-IR and mm

11 Formation of planetary systems Massive gas-rich disks Tenuous debris disks Planet building phase M(gas + dust)=0.01 M sun t=few Myr gas + dust interstellar M(dust)<1 M earth t>10 Myr dust produced in situ - Time scale for gas and dust dissipation? => Jovian planet formation timescale - Time scale for dust settling and grain growth? - Planet formation mechanism: core accretion vs. disk instability - Physical structure disks (T, n, v, ….)? - Chemical evolution gas + dust

12 Synergy ground-based facilities Dutrey et al. 2000

13 Example: Vega debris disk SimulationPdB 1mm data Wilner et al. 2002 Dust trapped in resonances due to unseen planet with few M Jup ? star What ALMA and JWST are expected to see…

14 Synergy between ground and space SIRTF/Herschel/submm bolometer arrays will detect (largely unresolved) mid- and far-infrared excesses around hundreds of stars of different age, luminosity, evolution stage, … ALMA and JWST-MIRI will have the sensitivity to detect and image dust in disks down to lunar masses at subarcsec resolution (down to 1 AU) out to distances of 300 pc VLTI-MIDI will be able to image the hot dust within few AU in brightest systems Herschel will provide peak luminosity and spectral energy distribution Complete spectroscopy 1  m to 3 mm of both gas and dust by combined VLT/JWST/Herschel/ALMA data in brighter systems GAIA essential to obtain accurate distances for analysis and statistics

15 Disks around brown dwarfs Example of synergy between facilities 10  1hr -Brown dwarf with VLT -Peak disk luminosity with Herschel (unresolved except in nearest objects) -Mass + image cold dust and gas with ALMA -Image warm gas with VLTI ALMA VLT Herschel BD Disk Natta & Testi 2001

16 Pathways to life? Based on Ehrenfreund & Charnley 2000 Search for building blocks of pre-biotic molecules

17 Links between disks and comets - Pre-biotic gas-phase molecules in disks with ALMA - Ices in disks with VLT/JWST/OWL - Silicates, organic refractory material with VLT/JWST/OWL Silicates in disk: mid-IR CO ice in disk: IR Organics in protostars: mm Malfait et al. 1998 Thi et al 2002 Cazaux et al. 2003

18 ALMA and JWST: perfect complement 0.3 - 7 mm 0.015 – few arcsec Thousands of lines by hundreds of gas- phase molecules CO as cold mass tracer Cold dust (10-100 K) 1 - 28  m 0.03 – 1 arcsec Major gas and solid- state species; PAHs; atomic lines Direct observation (warm) H 2 Warm dust (60-1000 K)


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