On-sky performance of SPHERE XAO system - Upgrade

On-sky performance of SPHERE XAO system
Upgrade perspectives
J.-F. Sauvage, T. Fusco, C. Petit
DOTA/HRA
Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
Science objectives
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High contrast imaging down to planetary masses
Investigate large target sample: statistics, variety of stellar
classes, evolutionary trends
Complete the accessible period window
First order characterization of the atmosphere (clouds,
dust content, Methane, water absorption, effective
temperature, radius, dust polarization)
 Understand the planetary system origins
Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
Ingredients of a high-contrast imager
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Large telescope
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High performance AO system to compensate for
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Atmospherical turbulence
Static optical aberrations
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A coronagraphic device to cancel out the main
part of the star light
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Dedicated post-processing methods enhancing
the planet signal wrt the star light residuals
Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
Two major international projects
Gemini Planet Imager - GPI
Gemini South
Amérique du nord
PI: Bruce Macintosh
Spectro-Polarimetric High-contrast Exoplanet REsearch
VLT-UT3
Europe
PI: Jean-Luc Beuzit
Journées Scientifiques de l’ONERA
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Châtillon, 20-21 janvier 2015
SPHERE : An outstanding instrument for VLT
PI : J.-L. Beuzit (IPAG)
PS: D. Mouillet (IPAG)
Ing. Système: K. Dohlen (LAM)
Resp. OA : T. Fusco (ONERA)
12 European institutes
10 years of development
25 M€ (consolidated)
250 FTE
8 tons
6x4x2.5m
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
The global concept of SPHERE
SAXO
Beam control
(DM, TT, PTT,
derotation)
Pola control
Calibration
Fore
optics
High frequency AO correction (41x41 act.)
High stability : image / pupil control
Visible – NIR Refraction correction
FoV = 12.5’’
40x40 SH-WFS in visible
1.2 KHz, RON < 1e-
Vis
Coronagraph
Extreme
AO
NIR
Coronagraph
Common Path
Pupil apodisation,
Focal masks: Lyot, A4Q, ALC.
IR-TT sensor for fine entering
Nasmyth platform, static bench,
Temperature control, cleanliness control
Active vibration control
Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
Coronagraphic imaging:
Dual polarimetry, direct BB + NB.
λ = 0.5 – 0.9 µm,
λ/2D @ 0.6 µm, FoV = 3.5”
ZIMPOL
IFS
IRDIS
0.95 – 1.35/1.65 µm
λ/2D @ 0.95 µm,
Spectral resolution: R
= 54 / 33
FoV = 1.77”
0.95 – 2.32 µm; λ/2D @ 0.95 µm
Differential imaging: 2 wavelengths, R~30,
FoV = 12.5’’
Long Slit spectro: R~50 & 400
Differential polarization
SPHERE : from the concept …
…to reality
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
SPHERE : from the concept …
…to reality
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
SPHERE : from the concept …
…to reality
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
From design to sky :
Say what we do, and do what we say
SAXO compliance matrix @ PAE
The on-sky system exactly fits the original design
Glasgow SPIE conf 2004
Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
SAXO : laboratory performance
Ultimate performance
: up to mag 9-10
Still a « decent » correction (a few tens of percent in H) : up to mag 15
2-3 mag better than the specfication !!!!
OCAM² - FLI company
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
First light
4 mai 2014 – 22:28 UT
« May the 4th be with us »
Definition of a First Light:
•First time the star light falls on detector
•Forget to record data
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
First light for SAXO
On sky data (May 2014)
H band 80% SR
J band 70% SR
Y band 60% SR
40x40 EMCCD filtered SH WFS
41x41 Piezzo DM
SAXO, le cœur de SPHERE
un cœur qui bat 1200 fois par seconde
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
Very first observations
Shape structure
ρ-3
 Diffraction
ρ-2
 WFS noise
ρ0
 WFS aliasing
Very first image
Spatial filter open
ρ-3
1
2
ρ-11/3  fitting
3
AO cut-off = 840 mas
4
5
4 / 5 Airy rings clearly visible
ρ -2
ρ0
ρ-11/3
WFS spatial filter = open
fc= 840 mas
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
Temporal stability
Saturated PSFs
20 min
Extremelly good stability of « static » speckle over a complete acquisition sequence
23:19 UT 23:36 UT
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
Image coronographique – 1ière détection
Naine blanche : m = 11
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
Experience vs simulation
2014/05/16
05:37 UT
seeing ~ 0.7
On sky data
1.9 λ/d
1.8 λ/d
1.45 λ/d
1.3 λ/d
Simulation
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
1.2 λ/d
1.1 λ/d
SPHERE vs GPI
GPI
GP
20 minutes in H band
15 minutes in H2 band
HD 165054, G4V, V=8.5
Preliminary reduced data
© A. Vigan (LAM)
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Journées Scientifiques de l’ONERA
Châtillon, 20-21 janvier 2015
Summary of SAXO perf (on sky)
Typical seeing / wind speed conditions = medium - bad
SR loss
SR loss
Laboratory data (0.85’’ seeing)
x 0.8
Perf evolution vs flux = OK (same as lab)
BUT : SR déficit ~ 15 / 20 %
SAXO preliminary on-sky error budget
75 %
Modal variance
Open loop
SR loss = Tip Tilt !!
~ 15 % of SR loss
Close loop
Tip Tilt modes
HODM modes
Fitting
Grand total
variance @ 1.6 µm (rad²)
0.15
0.088
0.04
0.24
Associated SR (%)
86.1 %
91.6 %
96 %
75.1 %
SR without TT = 88 %
SR with TT
= 75 %
SR on imgae = 75 %
The Tip-Tilt issue
High freq over-excitation ~ 10 mas !!!!
=> SR loss = 15 / 20 %
Open loop TT temporal spectrum
Residual jitter ~ 9 mas rms instead of 2 !
Limitation for very small inner working angle (< 0.1’’)
Limitation for VIS (= Zimpol) images (max SR < 25 %, FWHM > 20 mas)
Problem identified … ESO and SPHERE teams are working on possible solutions
Visible in open loop => not an AO loop issue
Not visible on internal data
Already seen on VLTI data !!!!
Probably related to M2 control
Test to be performed without M2 guiding
Closed loop TT temporal spectrum
FAQ : how to win 20% performance ?
Shut down M2 !!
M2 on
M2 off
SAXO : monitoring perf and turbulence
Strehl
r0
Wind
DM Sat
WFS Flux
DTT
Position
SAXO : monitoring perf and turbulence
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GEN_SPARTA data
Acquired for each OBS template
 30s sampling of SAXO quality
 Includes DTTS images => Non Corono perf
 Now : not completely forwarded in science
archive
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Philo : considere RTC as the 4th SPHERE
instrument
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Data provided into archive, as well as
science data
Down to very short separations
Imaging in I band (0.8 m)
H(0.65 m)
0.15’’
0.34’’
Zimpol PSF
V band (0.55 m)
H (0.65 m)
I band (0.82 m)
SPHERE-SAXO status
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COM4
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Full features now operational
 Vibration
filtering
 Automatic setup with flux
 Kalman on TT, OMG…
Full performance validated IR - VIS
 15% SR loss explained by secondary mirror
 M2 handling compatible with operation
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Science Verification
Now over
 First papers to be published
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Perspectives
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PSF Internal quality can be improved
Simple low order NCPA compensation (LIFT)
 Non-linear Dark Hole compensation
(COFFEE)
 On-sky estimation of NCPA
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Change the deformable mirror
Study pro/cons of different providers
 Optics design to be modified
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