with inputs from A Roberge D Defrère C Beichman W Danchi J C Augereau etc P3 panel exozodiacal disks We all live in a debris disk Asteroid collisions ID: 810732
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Slide1
O. Absil & C. Eiroawith inputs fromA. Roberge, D. Defrère, C. Beichman, W. Danchi, J.-C. Augereau, etc.
P3 panel: exozodiacal
disks
Slide2We all live in a debris disk!Asteroid collisionsComet outgassingDust is luminous (much more than the Earth)Dust is expected in any planetary systemDust in planetary systems
Kuiper
belt: 40 K, 50 AU
Zodiacal disk: 300 K, 1 AU
Slide3ObservationsDust not uniformly distributedSimulations
Earth at 1 AU
Stark &
Kuchner
2008
Slide410-100 zodi tolerable for closest targetsAsymmetries need thorough investigationThe exozodi issue: visible imaging
2m
4m
6m
8m
12m
Slide5Shot noise: 100 zodi tolerable in averagePreserves 75% of mission outcomeAsymmetries: ~10 zodi tolerableThe exozodi issue: IR interferometry
Slide6If Solar system is the rule, “Earth explorer” could just skip unsuitable systemsCan afford to loose some timeEZs interesting on their ownWhat if EZ mode is around 10 zodi? 100 zodi?Is the distribution log-normal at all? Bimodal?But ... do we really care?
100
zodi
?
10
zodi
?
< 1
zodi
?
Bad systems
100
10
1
0.1
0.01
1000
Slide7What we know: exo-Kuiper beltsDetected since 1984IRAS, ISO, SpitzerSensitivity ~ 100 × solarHerschelDown to 1 × solarActual distribution will soon be known for the cold partsWhat about warm parts?
100
×
solar
Bryden et al. 2006
Slide8What we want to know: exozodisMid-infrared most suitedPhotometrySpitzer: IRS, MIPSImaging10-m telescopes, (JWST)InterferometryKeck Nuller, VLTI/MIDINear-infrared can helpInterferometryCHARA/FLUOR, VLTI/VINCI
Slide9Exozodis: where we standIRS, MIPS1000 zodi at 3-σLarge sample~2% of systemsKeck Interferometer Nuller300 zodi at 3-σSmall sample (on-going)K-band interferometry 1000 zodi at 3-
σ
Small
sample
(on-
going
)~20% of MS stars with large amount of
hot
dust??
EZs
≠
from solar
zodi??
100
10
1
0.1
0.01
KIN
300
zodi
1000
Slide10Solution #1Use models to connect Kuiper belts with exozodisProblem: planetary system architecture matters!Solution #2Survey exozodis to build histogramWhat
should
be
the goal sensitivity
?Probably around 30 zodi (
3-
σ
)
Solution #3
Characterise
exozodis
around
all identified targets(need to wait for SIM or RV
detections, and to reach 10 zodi)
What
needs
to
be
done
?
Slide11What does it take?LBTIExpect ~30 zodi at 3-σSurvey starting > 201260 targets:
sufficient
?
Other
possible
nullers
ALADDINBalloonFKSI/Pegase
Other
instruments
Small
coronagraphs
:
need
to be
investigated
Slide12Invest in modellingProbability distribution (log-normal? bimodal? other?)How deep is enough? 30 zodi? Asymmetries: better predictions needed!Invest in LBTICould greatly reduce the exozodi problem if it lives up to the expectationsSupport development of other exozodi findersALADDIN, balloon, FKSI (share the same payload)Small coronagraphs?Conclusions / recommendations