Download Large filed of view and ELTs: an impossible marriage?

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Large field of view and ELTs: an
impossible marriage?
Paolo Ciliegi (INAF -OABO) on behalf of the MAORY team
Multi conjugate Adaptive Optics RelaY for the E-ELT
INAF (OA-Bologna, OA-Padova, IASF-Bologna, OA-Arcetri)
Università di Bologna
Office National d’Etudes et des Recherches
Aerospatiales
European Organisation for Astronomical Research in
the Southern Emisphere
Tomelleri s.r.l.
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
OUTLINE
•MAORY OVERVIEW : the multi conjugate adaptive optics
module for ELT
• THE LARGEST POSSIBLE FIELD OF VIEW @ ELT from
GLAO to DIFFRACTION LIMIT
• SYNERGIES BETWEEN SURVEY FACILITIES AND ELT.
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
What is MAORY?
 Multi conjugate Adaptive Optics RelaY for the E-ELT
 Corrected field of view
– Central unvignetted 53"x53"
– Maximum requested field Ø=120"
– Technical field Ø=160" for Natural Guide Star search
 Wavefront sensing
– 6 Sodium LGS WFS
LGS projected from M1 edge
– 3 NGS WFS
 Wavefront correction
– Telescope M4 + M5
– 2 post-focal deformable mirrors (4km, 12.7km)
 Output ports for science instruments
– Gravity invariant with mechanical derotation for MICADO
– Lateral port for detached instrument (no mechanical derotation)
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
3
What is MAORY?
 Client instruments
– MICADO
•
•
•
•
•
High angular resolution camera (and slit spectrograph)
Precision astrometry and photometry
Required AO correction: uniform with high sky coverage
Wavelength range 0.8-2.4µm. Field of view: 53"53"
MAORY thermal background < 50% (telescope + sky) @Ks
– SIMPLE
• High spectral resolution IR spectrograph
• Required AO correction: on-axis with high sky coverage
– Others
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
4
Overall layout
Pre-focal station
Nasmyth platform
MAORY
Area for detached instrument
Conference “Feeding the Giants: ELTs in the era of Surveys”
MICADO
Gravity invariant
port
Lateral port
-- Ischia 31/08/2011
5
Post-focal relay
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
6
Performance – Strehl Ratio
Seeing 0.8
0.6 arcsec
Ks 2.16µm
MAORY vs. ATLAS
ATLAS performance courtesy of T. Fusco
H 1.65µm
J 1.215µm
I 0.9µm
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
7
Performance – Sky coverage
Although we have 6 LGS projected from M1 edge, we still
need Natural Guide Stars (NGS) for
Tip Tilt correction
Sodium layer effects
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
9
Sky coverage…. where to search NGS
NGS WFS
MICADO
MAX FOV 160arcsec
53”
20”
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
10
Performance – Sky coverage





Sky coverage evaluated at North Galactic Pole
Reference conditions: Seeing 0.8", L0 = 25m
Random star counts generated by TRILEGAL code
3-NGS asterisms formed for each trial down to H ~ 21
“Best” asterism chosen. Figure of merit for each NGS asterism
– Measurement noise
– Temporal error
– Anisoplanatic errors (NGS positions and uneven brightness)
 Each star is assigned the Strehl Ratio value corresponding to its
position in the NGS seach field Ø = 160"
 Strehl Ratio comes from MCAO correction (1.5-1.8µm)
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
11
Performance – Sky coverage
Minimum field-averaged Strehl Ratio
Science field 53"53" (MICADO)
Sky Coverage
Ks
H
J
I
0.53
0.34
0.14
0.03
39%
0.51
0.32
0.13
0.03
50%
0.49
0.30
0.11
0.02
60%
0.47
0.27
0.09
<0.01
70%
0.41
0.22
0.06
<0.01
80%
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
12
THE LARGEST POSSIBLE FIELD OF VIEW @ ELT
LARGE FIELD OF VIEW AND ELT : AN IMPOSSIBLE MARRIAGE ?
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
13
THE LARGEST POSSIBLE FIELD OF VIEW @ ELT
LARGE FIELD OF VIEW AND ELT : AN IMPOSSIBLE MARRIAGE ?
The actual imaging camera designed for E-ELT is
MICADO characterized by superb capabilities in terms of
sensitivity (K ~ 30 mag AB, 5 sigma , 1-2 ours)
resolution (3 mas pix scale)
and astrometric precision.
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
14
THE LARGEST POSSIBLE FIELD OF VIEW @ ELT
LARGE FIELD OF VIEW AND ELT : AN IMPOSSIBLE MARRIAGE ?
The actual imaging camera designed for E-ELT is
MICADO characterized by superb capabilities in terms of
sensitivity (K ~ 30 mag AB, 5 sigma , 1-2 ours)
resolution (3 mas pix scale)
and astrometric precision.
The Micado Field of view is 53 x 53 arcsec.
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
15
53 x 53 arcsec field with a spatial resolution at the diffraction limit
level and a 3 mas pixels size is an impressive, huge field of view
that will open new frontiers in may astronomical fields
(see Greggio and Fiorentino talks)
MICADO 53’’x53’’
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
16
53 x 53 arcsec field with a spatial resolution at the diffraction limit
level and a 3 mas pixels size is an impressive, huge field of view
that will open new frontiers in may astronomical fields
….but of course is not a survey facility….
MICADO 53’’x53’’
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
17
WFI ESO 2.2m 2040’’ x 2040’’ (34’ x 34’)
MICADO 53 x 53 arcsec
WIRCAM CFHT near infrared 0.3’’/pixel
20’ x 20’
2 MASS 8.5’ x 8.5’
ACS HST
202’’x202’’
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
18
WFI at the ELT
Large deep imaging surveys have formed the backbone of
extra-galactic survey for the last 15-20 years and there is no
reason to expect this to change dramatically in the coming
years.
LSST
VISTA VST SASIR
Can we image a Wide Field Imager for ELT that can play a
direct role as survey facility?
Network Program “ Wide Field Imaging at the E-ELT :
from GLAO to diffraction limit”
PI . M. Arnaboldi (ESO) (E-TRE-ESO-508-0755)
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
19
We investigate the possibility for a Wide
Field Imager exploiting the full MCAO
corrected field
Balance between
NGS search field
NGS WFS
Number of detectors
90 x 90 arcsec
Pixel MICADO
scale : 8-10mas
MAX FOV 160arcsec
53”
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
20
ELT and Large Field of view
Maximum field of view at a resolution slightly worse
than diffraction limit (8-10 mas pixel scale) is about
90 x 90 arcsec.
We can reach bigger field of view (tens of squared
arcmin, 5’x5’) but we must accept moderate
resolution at the level of the GLAO correction.
These numbers confirm the difficulty of the giant
telescopes to work alone as survey facilities,
highlighting the absolute need for synergies among
different facilities.
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
22
SYNERGY --- MAORY and NEAR
INFRARED SURVEY
Which is the fundamental “food” for MAORY ?
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
23
SYNERGY --- MAORY and NEAR
INFRARED SURVEY
Which is the fundamental “food” for MAORY ?
In our sky coverage calculation, we simulated the availability of a
deep (down to H=21) infrared catalogue
For real observations we need real deep catalogues with:
Reliable stars/galaxies separation.
Accurate position (NGS probe have a FoV of 3’’)
These catalogue must be already available at the time of the proposal in
order to check the NGS asterism.
Deep near infrared catalogues will be a fundamental input
that forthcoming survey facilities like VISTA and SASIR
must provide to ELT.
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
24
CONCLUSION
THE COUPLED MAORY + MICADO IS A FANTASTIC TOOL IN TERMS OF STREHL
RATIO, EE, SENSIBILITY RESOLUTION AND ASTROMETRIC PRECISION
…HOWEVER WITH A FOV OF 53 X 53 arcsec is not an instrument for surveys
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
25
CONCLUSION
THE COUPLED MAORY + MICADO IS A FANTASTIC TOOL IN TERMS OF STREHL
RATIO, EE, SENSIBILITY RESOLUTION AND ASTROMETRIC PRECISION
…HOWEVER WITH A FOV OF 53 X 53 arcsec is not an instrument for surveys
We investigate the possibility for a Wide Filed imager @ ELT.
At resolution slightly worse than diffraction limit the maximum FoV is ~ 90 x 90 arcsec,
while at GLAO resolution is 5 x 5 arcmin.
…. So Large Field of views and ELT seems to be an impossible marriage !!!
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
26
CONCLUSION
THE COUPLED MAORY + MICADO IS A FANTASTIC TOOL IN TERMS OF STREHL
RATIO, EE, SENSIBILITY RESOLUTION AND ASTROMETRIC PRECISION
…HOWEVER WITH A FOV OF 53 X 53 arcsec is not an instrument for surveys
We investigate the possibility for a Wide Filed imager @ ELT.
At resolution slightly worse than diffraction limit the maximum FoV is ~ 90 x 90 arcsec,
while at GLAO resolution is 5 x 5 arcmin.
…. So Large Field of views and ELT seems to be an impossible marriage !!!
…. This impossible marriage implies that the synergies between survey
facilities and giant telescopes are fundamental.
As an example we show that large (possible all sky) deep (H~ 21) near infrared
catalogues are a fundamental input that forthcoming survey facilities must
provide to ELT
Conference “Feeding the Giants: ELTs in the era of Surveys”
-- Ischia 31/08/2011
27