1

Study of an adaptive Study of an adaptive optics system for the optics system for the

astronomy in the astronomy in the visiblevisible

Study of an adaptive Study of an adaptive optics system for the optics system for the

astronomy in the astronomy in the visiblevisible

Sandrine Thomas,Sandrine Thomas,A. Tokovinin, N. van der Bliek, B. Gregory, A. Tokovinin, N. van der Bliek, B. Gregory,

R. Tighe, R. Cantarutti, P. Schurter, E. Mondaca, D. R. Tighe, R. Cantarutti, P. Schurter, E. Mondaca, D. SprayberrySprayberry

Santa Cruz, Santa Cruz, 2nd of March2nd of March 2006 2006

2

OutlineOutlineOutlineOutline

Limitations of classical AOs Limitations of classical AOs GLAO technics GLAO technics (Ground Layer Adaptive Optics) (Ground Layer Adaptive Optics)

Description and performanceDescription and performance

Example of SAM Example of SAM (SOAR Adaptive Module)(SOAR Adaptive Module)

TurSim, BIM60, Laser, WFSTurSim, BIM60, Laser, WFS

Shack-Hartmann WFS studyShack-Hartmann WFS study

4

Main lMain limitations of AOimitations of AOMain lMain limitations of AOimitations of AO

Low sky coverageLow sky coverage

Small isoplanetic angle (a few arcsec)Small isoplanetic angle (a few arcsec)

Difficult correction in the visibleDifficult correction in the visible

Np

h

Np

h

per

cm

per

cm

22 an

d p

er s

econ

de

an

d p

er s

econ

de

Wavelength in micronsWavelength in microns

CorrectioCorrection n possiblepossible

CorrectioCorrection n impossiblimpossiblee

5

SolutioSolutionsnsSolutioSolutionsns

Sky coverage solution Sky coverage solution = laser guide star= laser guide star

But: But: cone effect and cone effect and

Tip/tilt problemTip/tilt problem

Anisoplanetism solutionAnisoplanetism solution: 3D turbulence : 3D turbulence reconstruction (tomographyreconstruction (tomography + MCAO + MCAO) )

BUTBUT:: complex systemcomplex system

Correction in the visible Correction in the visible : increase of : increase of the number of actuatorsthe number of actuators

BUTBUT:: complex and flux problem complex and flux problem

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GLAOGLAOGLAOGLAO

Tomography Tomography = measure in 3D of = measure in 3D of the turbulencethe turbulence

Only one starOnly one star:: use of the cone use of the cone efeffet fet (+ measure of the tip/tilt)(+ measure of the tip/tilt)

dhHhhglobal222 )/1()(

GLAO = measure and GLAO = measure and correction of the ground correction of the ground layerlayer

• Uniform correction over a Uniform correction over a larger FoVlarger FoV• Gain in resolution in the Gain in resolution in the visiblevisible

HH

hh

n WFSsn WFSs

n guides n guides starsstars

CommandCommand

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Why is it working?Why is it working? Turbulence profilesTurbulence profiles

Why is it working?Why is it working? Turbulence profilesTurbulence profiles

Good night

Bad night

Tokovinin et al. 2003, campain at Cerro PTokovinin et al. 2003, campain at Cerro Pààchonchon

60%60%

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Performance of Performance of SAMSAMPerformance of Performance of SAMSAM

COMPENSATION: COMPENSATION: wide FoV (ex 3’)wide FoV (ex 3’)COMPENSATION: COMPENSATION: wide FoV (ex 3’)wide FoV (ex 3’)

On-axisOn-axis 1’1’ 2’2’ 3’3’ SeeingSeeing

0.7 μm

Wide FoVWide FoVVVisibleisible

GLAOGLAO+ +

1 laser guide star1 laser guide star

Good sky Good sky coverage coverage Improvement Improvement in FHWM (factor in FHWM (factor 2-5)2-5)

SAM SAM and my and my contributionscontributions

TurSimTurSim

OAPsOAPsWFSWFS

DMDM

Tokovinin A. et al, SPIE, Tokovinin A. et al, SPIE, 20042004

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Optical designOptical designOptical designOptical design

Total Total transmission transmission

==0.85-0.90.85-0.9

atat = [0.4-0.9]= [0.4-0.9]mm

TurSim

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TurSimTurSimTurSimTurSim

Physical simulation of the Physical simulation of the atmospherical turbulence atmospherical turbulence Different atmospherical Different atmospherical

conditions possibleconditions possibleDifferent speeds Different speeds Different sources: Different sources:

Diode lDiode laser, aser, LEDLED UV, UV, LEDLED white white

rr00 300 300 m m atat 633 nm 633 nmAdjustable Adjustable

beam diameterbeam diameter

d/rd/r00 << 4545/r0

/dPSFPSF

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TurSimTurSimTurSimTurSim

Zernike Zernike decompositiondecomposition

i

ii rZar )()(

0

2

rDNa ii

Optical transfert Optical transfert functionfunction

35044.3exp)( rffOTF

noisnoisee

rr00

Thomas S., SPIE, 2004

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Choice of the DMChoice of the DMChoice of the DMChoice of the DM

SimulatedSimulated

MeasureMeasuredd

Tests of the electrostatic mirror OKO79 Tests of the electrostatic mirror OKO79 from OKOTECH then of the bimorph miroir from OKOTECH then of the bimorph miroir BIM60 from CILAS:BIM60 from CILAS: Stroke and inter-actuators strokeStroke and inter-actuators stroke AberrationsAberrations Influence functions ….Influence functions ….

BIM60BIM60

Tokovinin A., Thomas S., Vdovin G., SPIE, 2004

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SAM’s DMSAM’s DMSAM’s DMSAM’s DM

Pupil = 60 mm Pupil = 60 mm

but but 50 mm50 mm used used

6060 actuarors actuarors

Radius of curvature Radius of curvature

== 16.2 m16.2 m

Astigmatism = Astigmatism = 3 3 mm

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DMDM

WFS moduleWFS module

TurSimTurSim

CCD CCD

SAM’s prototypeSAM’s prototypeSAM’s prototypeSAM’s prototype

ReferenceReference

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Closed-loopClosed-loopClosed-loopClosed-loop

Image quality after correction of the mirror Image quality after correction of the mirror aberrations 20 nmaberrations 20 nm rms rms

DM uncorrectedDM uncorrected DM correctedDM corrected

Turbulence characteristicsTurbulence characteristics

Closed-loop study Closed-loop study

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Starfire Optical Range (SOR)Starfire Optical Range (SOR)Albuquerque, NMAlbuquerque, NM

LaserLaserLaserLaser

Laser: • Nd:YAG 355nm triple, 8W at 10 kHz• LLT: D = 30cm, behind secondary, H=10km• Gating: KD*P Pockels cell, dH=150m

Tip/tilt Measurement: 2 NGS (R<18)• Quad cell • APDs connected to fiber optics

Why UV?Why UV?High Rayleigh diffusion High Rayleigh diffusion ((-4-4))

Easy separation between science and Easy separation between science and WFSWFS

No visual hazardNo visual hazard

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The SHWFSThe SHWFSThe SHWFSThe SHWFS

Good precision Good precision of the position of the position measurementmeasurement

Good Good

reconstruction reconstruction of the of the

distorted distorted wavefrontwavefront

22errerr = = (C(Cmes mes – C– Ctruetrue))22

1000 iter1000 iter

Distorted wavefront Distorted wavefront Micro-lens Micro-lens

array array

DetectorDetectorCCD CCD camera camera

Spot position Spot position Reference Reference positionposition

(in collaboration (in collaboration mainly with T. Fusco, mainly with T. Fusco, A. Tokovinin)A. Tokovinin)

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Front d’onde planFront d’onde plan

ContextContextContextContext

AtmosphèreAtmosphèreAtmosphere + Atmosphere + photon and readout photon and readout

noisenoise

Parameters of the studyParameters of the study

• Spot shapeSpot shape• Turbulence Turbulence strength strength rr00

• Photon number per Photon number per subaperture: subaperture: NNphph

• Readout noise: Readout noise: NNrr

• Subaperture FoV Subaperture FoV • Spatial resolution:Spatial resolution: Nyquist, NyquistNyquist, Nyquist/2/2

Nph= 200Nsamp= 2D/r0= 2Nr= 3

Monte-Carlo simulationMonte-Carlo simulation

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Centroid calculation Centroid calculation methodsmethods

Centroid calculation Centroid calculation methodsmethods

CoG:CoG:• Thresholding, TThresholding, T• Windowing, WWindowing, W• Weighted CoG, Weighted CoG, FFww

Quad CellQuad Cell

CorrelationCorrelation

jiji

jijiwjii

x I

FIx

C

,,

,,,,

IrIl

IrIlCx

ji

iiwjiwcorr yyxxFIFIyxF,

, ),(),(

Correlation peak estimation:Correlation peak estimation:

Non-linearity

Ctrue

Cmes

CoG + CoG + thresholding, Tthresholding, T Parabola fittingParabola fitting Gaussian fittingGaussian fitting

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20

20

2222 )(1)( atmnlNNerr xfxphr

Error variance expressionError variance expressionError variance expressionError variance expression

22errerr = = (C(Cmes mes – C– Ctruetrue))22

1000 iter1000 iter

ResponsResponse e

coefficiecoefficientnt Non-Non-

linearilinearity ty

termterm

Term from Term from atmosphericatmospheric

alaldistortionsdistortions

Noise Noise termsterms

26

22

2 1

2ln2

samp

T

phN N

N

Nph

Noise termsNoise terms Noise termsNoise terms

2

4

2

222

3 samp

s

ph

rN N

N

N

Nr

CoGCoG

WCoG WCoG (corrected (corrected by by ))

CorrelatioCorrelationn

4222

4222

22

2

1

2ln2 wwT

wT

samp

T

phN NNN

NN

N

N

Nph

42

422

2

2

2

22

)2(ln32 wsamp

wT

ph

rN NN

NN

N

Nr

Hyp: Nyquist, Gaussian spotHyp: Nyquist, Gaussian spot

PaperPaper:: Thomas et al. submitted Thomas et al. submitted

2

2222 44

2

ph

r

samp

N N

N

Nr

2

22 1

2ln2

samp

T

phN N

N

Nph

Hyp: Nyquist, diffraction spotHyp: Nyquist, diffraction spot

Ns = pixels numberNt = spot FWHMNsamp = Sampling = correlation function FWHMW = FoV

phN N

Wph

22

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Term from atmosphericalTerm from atmospherical distortionsdistortions

Term from atmosphericalTerm from atmospherical distortionsdistortions

Atmospherical Atmospherical turbulence onlyturbulence only

35

0

22 5.0

rdWatm

For CoG -For CoG -corrcorreelation lation

For 4Q For 4Q 35

0

2 07.0

rd

atm(W)(W)

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W optimizationW optimizationW optimizationW optimization

Weak turbulenceWeak turbulence

Photon noise Photon noise and and atmospherical atmospherical turbulenceturbulence

35

0

22 5.02

rdW

N

W

ph

(W)(W)

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Methods comparisonMethods comparisonMethods comparisonMethods comparisonProsPros ConsCons

ThresholdThresholding ing ––WindowinWindowingg

Reduction of noisy Reduction of noisy pixelspixels

Not robust at low fluxNot robust at low flux

Quad CellQuad Cell Robustness and good Robustness and good noise propagation at low noise propagation at low flux and high Nflux and high Nrr

Response coefficient to Response coefficient to adjust and difficult to adjust and difficult to estimateestimate

Non-linear, not precise Non-linear, not precise at high fluxat high flux

Weigthed Weigthed windowinwindowingg

Robustness and good Robustness and good noise propagation noise propagation

Response coefficient to Response coefficient to adjustadjust

CorrelatioCorrelationn

Independent from the Independent from the size and shape of the size and shape of the spotspot

Peak determinationPeak determination

Big calculation Big calculation

By adapting the parameters for each method, it is possible to By adapting the parameters for each method, it is possible to find the minimum error with the minimum of changes find the minimum error with the minimum of changes

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ExampleExample 1: Planet Finder 1: Planet Finder ExampleExample 1: Planet Finder 1: Planet Finder

WCoGWCoG--CorrelationCorrelation

Nyquist, NNyquist, Nrr= 0.5 e-, = 0.5 e-, d/rd/r00=1=1

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SAM WFSSAM WFSSAM WFSSAM WFS

Shack-Hartmann Shack-Hartmann • 10x10 sub-apertures10x10 sub-apertures• 8x8 pixels per subapertures8x8 pixels per subapertures• UV-Visible (UV-Visible (1100-100-11100 nm)00 nm)

CCD-39 EEV + controler SDSU-III CCD-39 EEV + controler SDSU-III • Readout noise = 5.9eReadout noise = 5.9e- - at 200 Hz at 200 Hz• Binning capacity (Binning capacity (1x1, 2x2, 4x41x1, 2x2, 4x4))

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ExampleExample 2: SAM 2: SAMExampleExample 2: SAM 2: SAM

QC then QC then WCoGWCoG-correlation-correlation

Nyquist/2, NNyquist/2, Nr r = 5 e-, = 5 e-, d/rd/r00=2=2

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ConclusionConclusions 1s 1ConclusionConclusions 1s 1

Adaptive optics wide FoV in the visible Adaptive optics wide FoV in the visible Study of the main components of SAMStudy of the main components of SAM

TurSim: Development et validation TurSim: Development et validation MD: Validation and test of 2 types of mirrorMD: Validation and test of 2 types of mirrorContribution to the optical designContribution to the optical designDevelopment and use of a prototype Development and use of a prototype

Theoretical study and simulation of a SH WFS: Theoretical study and simulation of a SH WFS: Definition of an error budgetDefinition of an error budgetComparison of different methods of spot positionComparison of different methods of spot positionDevelopment of analytical expressions Development of analytical expressions Application to different type of systemsApplication to different type of systems

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Search for tertiary Search for tertiary companions to close companions to close spectroscopic binariesspectroscopic binaries

Search for tertiary Search for tertiary companions to close companions to close spectroscopic binariesspectroscopic binaries

HIP 48215

VLT4VLT4

In collaboration with A. Tokovinin, M. Sterzik, S. Udry

Tokovinin A., Thomas S., Sterzik M., Udry S., A&A, 2006

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ContextContextContextContext

How do we explain the separation of How do we explain the separation of close binaries of a few days?close binaries of a few days?

Molecular cloudMolecular cloud

HowHow??

Accre

tion

Accre

tion

Close binariesClose binaries

Angular Angular momentumomentumm

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Close binaries formation Close binaries formation Close binaries formation Close binaries formation IdeaIdea:: orbital shrinkageorbital shrinkageMagnetic breaking or disk breaking…Magnetic breaking or disk breaking…Evolution like Kozai cycle (Kozai 1962) Evolution like Kozai cycle (Kozai 1962)

Hypothesis: deposition of the angular momentum in Hypothesis: deposition of the angular momentum in a tertiary componenta tertiary component

Existence = Melo et al. 2001, SimulationExistence = Melo et al. 2001, Simulationss: Sterzik et al. 2003: Sterzik et al. 2003

qq1, 1,

PP11~10d~10d

qq3, 3, PP33~10~1044 yryr

Loi de Loi de Kepler’s :Kepler’s : M

P

a2

3

a = demi granda = demi grand--axeaxeq = rapport des massesq = rapport des massesP = période P = période

??

QuestionQuestion: : Are tertiaries Are tertiaries needed in the SBs needed in the SBs formation?formation?Are all SBs part of a Are all SBs part of a multiple system?multiple system?

Eggleton 2001, Eggleton 2001, Kiseleva-Eggleton,Kiseleva-Eggleton, 20042004

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Tertiary detectionTertiary detectionTertiary detectionTertiary detection

Close < 100pc Close < 100pc (Hipparcos) larger (Hipparcos) larger separations separations

Periods [1Periods [1jj – 30 – 30jj] ] CORALIE, Batten et al. CORALIE, Batten et al. (1989), recent paper(1989), recent paper

DwarfsDwarfs from from 0.4 to 1.7 0.4 to 1.7

MM.. ( more numerous( more numerous,, close, not close, not

too bright and sharp lines.)too bright and sharp lines.)

SampleSample

HIP 279030pc, G8V

TechnicsTechnics

165 SBs in 161 systems165 SBs in 161 systems

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NACO: AO on Yepun (VLT4)NACO: AO on Yepun (VLT4)NACO: AO on Yepun (VLT4)NACO: AO on Yepun (VLT4)

2 runs2 runs:: Novembre Novembre 2004 and July 20052004 and July 2005Band K + bands J H for Band K + bands J H for some of Nov.some of Nov.72 objects observed +72 objects observed +

2 calibrators2 calibrators

1pixel = 13.30 13.30 masmas

• NACO: Imagery, NACO: Imagery, polarimetry, spectroscopy, polarimetry, spectroscopy, coronography coronography • = 1= 1--5 5 m.m.• R ~ 50% in K band with a R ~ 50% in K band with a reference star of V=12 reference star of V=12

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Example of companionsExample of companionsExample of companionsExample of companions

HIP 98578HIP 98578

1 = 3.70” 1 = 340K = 2.25

2 = 0.39”2 = 353K = 0.62

AA

BB

CC

= = SBSBRepresentative Representative narrow-band images narrow-band images FoV = 2’’ x 2’’FoV = 2’’ x 2’’

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Data reductionData reductionData reductionData reductionRegular data reduction, package EclipseRegular data reduction, package EclipseDAOPHOT procedureDAOPHOT procedure:: fitting of the fitting of the image with the primary.image with the primary.PSF extractionPSF extraction

• Position error Position error = 0.5 mas if = 0.5 mas if m<3m<3mm and 5 mas if and 5 mas if m=5m=5mm

• rms magnitude difference error rms magnitude difference error = 0.02= 0.02mm if if m<3m<3mm and and 0.050.05mm if if m=5m=5mm

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Detection limitDetection limitDetection limitDetection limit

33 detection detection from from I I ((rr,,))

Check with Check with simulationsimulation

ModelModel

Separation in arcsecSeparation in arcsec

mm

43

= 0.1”, = 0.1”, m m = 3= 3

HIP86289HIP86289

False detectionsFalse detectionsFalse detectionsFalse detections

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Search for wider companionsSearch for wider companions Search for wider companionsSearch for wider companions

1. Extract data, 1. Extract data, <2’<2’2. Plot CMD (2. Plot CMD (J, J-KJ, J-K))3. Select candidates < 0.23. Select candidates < 0.2mm

from the main sequencefrom the main sequence

N* = 8

2 physical companions2 physical companions

POSSPOSS: :

Palomar Observatory Sky SurveyPalomar Observatory Sky Survey

2MASS2MASS

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Period distributionPeriod distributionPeriod distributionPeriod distribution

BinariesBinariesTertiariesTertiaries

SBs with a tertiaires have a SBs with a tertiaires have a significatively significatively larger larger fraction of systems with fraction of systems with PP11<10<10dd

Period P1, dPeriod P1, d

NN PP33=10=104 4

PP11

PP33 = 5 = 5 PP11

MSC catalogMSC catalog ((Tokovinin,1997)Tokovinin,1997)

Our observationsOur observations

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q3q3logP3logP3

Pro

bab

ilit

yP

rob

ab

ilit

y

Correction for incomplete Correction for incomplete detectiondetection

Correction for incomplete Correction for incomplete detectiondetection

Correction done by maximum likelyhoodCorrection done by maximum likelyhood

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Fraction of tertiary vs SB’s Fraction of tertiary vs SB’s period period

Fraction of tertiary vs SB’s Fraction of tertiary vs SB’s period period

96% of SBs with P<396% of SBs with P<3dd have tertiaries have tertiaries96% of SBs with P<396% of SBs with P<3dd have tertiaries have tertiaries

Less SBs have Less SBs have tertiariestertiariesLess SBs have Less SBs have tertiariestertiaries

Robust Robust methodmethod

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ConclusionsConclusions 2 2ConclusionsConclusions 2 2

Tertiary fraction depends on the period PTertiary fraction depends on the period P11 of the SBsof the SBs– For PFor P11<3<3dd, almost all SBs , almost all SBs multiple systems multiple systems– If PIf P1 1 is bigger, is bigger, pure SBs. Tertiary frequency < pure SBs. Tertiary frequency <

one of solar type systemsone of solar type systems

Different period distribution between Different period distribution between triple and binariestriple and binariesSame mass distributionSame mass distribution

No relation between PNo relation between P11 and P and P33

Most massive component = closest one Most massive component = closest one pure SBs pure SBs no Kozai cycle no Kozai cycle

Hyp: accretion, Hyp: accretion, disk brakingdisk braking..

SBSBs s could have lost their could have lost their tertiariestertiaries..

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PerspectivesPerspectivesPerspectivesPerspectives

Implementation of GLAO systems Implementation of GLAO systems 1st generation of AO for the ELTs1st generation of AO for the ELTsFollow-up of the WFS study in the case Follow-up of the WFS study in the case of a laser guide starof a laser guide star

Problem of SBs is only partially Problem of SBs is only partially resolvedresolvedOther science: Brown dwarf formation, Other science: Brown dwarf formation, Herbig AeBe star formation.Herbig AeBe star formation.

50MERCI A TOUSMERCI A TOUSMERCI A TOUSMERCI A TOUS