Download EPICS, exoplanet imaging with the E-ELT

EPICS, exoplanet imaging with the E-ELT
Markus Kasper, Jean-Luc Beuzit, Christophe Verinaud, Emmanuel AllerCarpentier, Pierre Baudoz, Anthony Boccaletti, Mariangela Bonavita,
Kjetil Dohlen, Raffaele G. Gratton, Norbert Hubin, Florian Kerber, Visa
Korkiaskoski, Patrice Martinez, Patrick Rabou, Ronald Roelfsema, Hans
Martin Schmid, Niranjan Thatte, Lars Venema, Natalia Yaitskova
ESO, LAOG, LESIA, FIZEAU, Osservatorio Astronomico di Padova,
ASTRON, ETH Zürich, University of Oxford, LAM, NOVA
AO4ELT, Paris, 23 June 2009
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Outline

Science goals (6s)
 Instrument and AO concept (12s)
 Science Output prediction (4s)
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Exoplanets observations early 2009



~ 300 Exoplanets detected, >80% by radial velocities, mostly gas
giants, a dozen Neptunes and a handful of Super-Earths
Constraints on Mass function,
orbit distribution, metallicity
Some spectral information from
transiting planets
HR 8799, Marois et al 2008
Beta Pic, Lagrange et al 2009
Spectrum of HD 209458b
AO4ELT, Paris, 23 June 2009
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Richardson et al., Nature 445, 2007
(Some) open issues
 Planet
formation (core accretion vs gravitational
disk instability)
 Planet evolution (accretion shock vs spherical
contraction / “hot start”)
 Orbit architecture (Where do planets form?, role of
migration and scattering)
 Abundance of low-mass and rocky planets
 Giant planet atmospheres
AO4ELT, Paris, 23 June 2009
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Object Class 1, young & self-lum
Planet formation
in star forming regions or young associations
Requirements:
• High spat. resolution of ~30 mas
(3 AU at 100 pc, snow line for G-star )
• Moderate contrast ~10-6
AO4ELT, Paris, 23 June 2009
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Object Class 2, within ~20 pc
Orbit architecture, low-mass planet abundance
~500 stars from Paranal ± 30 deg, ~60-70% M-dwarfs
Requirements
• High contrasts
~10-9 at 250 mas
(Jupiter at 20pc)
• + spatial resolution
~10-8 at 40 mas
(Gl 581d,~8 M)
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Object Class 3, already known ones
Planet evolution and atmospheres
discovered by RV, 8-m direct imaging (SPHERE, GPI) or
astrometric methods (GAIA, PRIMA)
From ESO/ESA WG report
GAIA discovery space
SPHERE discovery space
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Contrast requirements summary
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Concept
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Concept: Achieve very high contrast
Highest contrast observations
require multiple correction
stages to correct for
1.
2.
3.
Atmospheric turbulence
Diffraction Pattern
Quasi-static instrumental
aberrations
Diff. Pol.
Visible diffraction
suppression
XAO
NIR diffraction
suppression
Coherencebased
concept?
IFS
XAO, S~90%
Diffraction + static
aberration correction
Contrast ~ 10-3-10-4
Contrast ~ 10-6
Speckle Calibration,
Differential Methods
Contrast ~ 10-9
x 1000 !
AO4ELT, Paris, 23 June 2009
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XAO concept
Main parameters
(baseline)
AO + coro

Serial SCAO
M4 / internal WFS,
XAO
 XAO: roof PWS at
825 nm, 3 kHz
 200x200 actuators
(20 cm pupil spacing)
RTC requirements:
Efficient algorithms
studied outside
EPICS phase-A
1e-6
1e-7
Numerical simulation, see poster of Visa Korkiakoski
AO4ELT, Paris, 23 June 2009
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High Order Testbench (HOT)
Demonstrate XAO / high contrast concepts


Developed at ESO in collaboration with Arcetri and Durham Univ.
Turb. simulator, 32x32 DM, SHS, PWS, coronagraphy, NIR camera
H-band Strehl ratios ~90% in 0.5 seeing (SPIE 2008, Esposito et al.
& Aller-Carpentier et al. ) correcting 8-m aperture for ~600 modes
See poster of Aller-Carpentier
100
95
90
85
SR (%)

80
75
70
65
60
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AO4ELT, Paris, 50
232 June 2009
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6
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Star magnitude
10
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HOT: XAO with APL coronagraph
 700K object next to K0 star
• Good agreement with
SPHERE simulations
• Additional gain by quasi-static
speckle calibration (SDI, ADI)
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HOT speckle stability
0
+ 6hrs
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+30 hrs
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Correction of quasi-static WFE incl.
segments piston
DM “cleans” its control area from speckles
 Need: measure static aberrations some nm level at science
wavelength through residual turbulence (PD or Speckle
Nulling)

Standard WFE specs ok for
most optics (near pupil)
Concept to be demonstrated
 FP7 funded exp.
(FFREE@LAOG and HOT)
AO4ELT, Paris, 23 June 2009
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HOT: Segments piston and correction of
quasi-static WFE
0.3
0.25
0.2
0.15
0.1
0.05
HOT pupil with DM and segmentation
AO4ELT, Paris, 23 June 2009
With segmentation
Residual PSF calibration
Getting from systematic PSF residuals (10-6-10-7) to 10-8-10-9
 Spectral Devonvolution (Sparks&Ford, Thatte et al.),
Trade-off: spectral bandwidth vs inner working angle,
 IFS (baseline Y-H)

Multi-band spectral or polarimetric differential imaging for smallest
separation, needs planet “feature” (e.g. CH4 band, or polarization)
 IFS and differential polarimeter (600-900 nm)

Coherence based methods (speckles interfere with Airy Pattern, a
planet does not)
 Self-Coherent camera (see talk by P. Baudoz)

Angular Differential Imaging (ADI)  All
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Example: Spectral Deconvolution
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Speckle chromaticity and Fresnel
SD needs “smooth” speckle spectrum
-> near-pupil optics
20 nm rms at
10x Talbot
20 nm rms in
pupil plane
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End-2-end analysis
Apodizer only leads to improved final contrast
APLC
Apodizer
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E-ELT WFE requirements
 Segment
 Segment
alignment (PTT)
figuring
 Segment high orders
 M2-5, f>50 cycles/pupil
 Roughness
< 36 nm rms
< 50 nm rms
< 50 nm rms
< 30 nm rms
< 5 nm rms
AO4ELT, Paris, 23 June 2009
Baseline Concept
All optics near the pupil plane
minimize amplitude errors and speckle irregular chromaticity
AO4ELT, Paris, 23 June 2009
Detection rates, MC simulation
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Predicted Science Output
MC simulations
 planet population with orbit and mass
distribution from e.g. Mordasini (2007)
 Model planet brightness (thermal,
reflected, albedo, phase angle,…)
 Match statistics with RV results
Contrast model
 Analytical AO model incl.
realistic error budget
 Spectral deconvolution
 No diffraction or static WFE
 Y-H, 10% throughput, 4h obs
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Detection rates, nearby+young stars
Contrast requirements
Mordasini et al. 2007
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Predicted EPICS output
Target
class
# targets
Selfluminous
planets
Giant
planets
Neptunes
Rocky
planets
1. Young
stars
2. Nearby
stars
3. Stars
w. planets
688
~100
(~100)
Dozens
512
Dozen
~100
Dozens
Very few
(?)
Dozen
>100
Some
>100
>Dozen
>2
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Summary

EPICS is the NIR E-ELT instrument for Exoplanet
research
 Phase-A to study concept, demonstrate feasibility by
prototyping, provide feedback to E-ELT and come up
with a development plan
 Conclusion of Phase-A early 2010
 Exploits E-ELT capabilities (spatial resolution and
collecting power) in order to greatly advance Exoplanet
research (discovery and characterization)
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END
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