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 MEarth 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

Planetary search methods

Perryman 2000

Planetary search methods

Perryman 2000

- HARPS 1 m/s => > Saturn out to 5 AU with 10 yr monitoring- VLTI 10 mas => > 10 MEarth in terrestrial planet forming zone

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)

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

Ground-based spectrum of nearest T dwarf

Scholz et al. 2003

Need space to observe critical H2O and CH4 bands

Model exo-planetary atmospheres

Note change in mid-infrared spectral features with age

Based on Burrows et al. 1997

Exo-earths with OWL• Sun is ~1010 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 D4 ! )

• Spectroscopy– Exo-biospheres?

Gilmozzi 2003

Solar system @10 pc

Jupiter @5AU Earth @1AU

OWL 100mJ Band80% Strehl104 sec0.4’’ seeing

O.1’’

Gilmozzi 2003

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 imagesat mid-IR and mm

Formation of planetary systems

Massive gas-rich disks

Tenuous debris disks

Planet buildingphase

M(gas + dust)=0.01 Msun

t=few Myrgas + dust interstellar

M(dust)<1 Mearth

t>10 Myrdust 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

Synergy ground-based facilities

Dutrey et al. 2000

Example: Vega debris disk

Simulation PdB 1mm data

Wilner et al.2002

Dust trapped in resonances due to unseen planet with few MJup?

star

What ALMA andJWST are expectedto see…

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

Disks around brown dwarfsExample of synergy between facilities

101hr

-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

BDDisk

Natta & Testi 2001

Pathways to life?

Based on Ehrenfreund & Charnley 2000

Search for building blocks of pre-biotic molecules

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

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) H2

• Warm dust (60-1000 K)