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HIGH RESOLUTION & CONTRAST Imaging F. Pedichini
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PARSEC: 3.26 ly 1 Pc 3 Pc 1 A.U. 1 arcsec 2 arcsec
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EXO_Planets @ 10 pc 5 A.U. 3 A.U. 1 A.U. 10 pc 100 mas 500 mas 300 mas 1rad = 206265 arcsec [1 mas = 1e-3 arcsec]
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Airy disc @ telescope [mas] : 1.22λ/D Lambda [µm]Mirror 0.1Mirror 1.0Mirror 10Mirror 40Mirror 100 0.35880888.82.20.8 0.65163416316.34.01.6 2.5628462862.815.76.3 10251362513251.362.825.13
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Airy disc @ 8.2 m, high contrast: Sun flux @ 10pc = 1.5e9 γ/s [R band] [mas] Peak normalized flux 1.22λ/D @ 630 nm ~ 18 mas
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Sun flux @ 10pc = 1.5e9 γ/s [R band] Jupiter flux @ 10pc, 5A.U. = 5.0 γ/s [R band] Jupiter flux @ 10pc, 1A.U. = 125 γ/s Jupiter flux @ 10pc, 0.5A.U. = 600 γ/s
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Planet contrast vs Sun distance: [mas] Diffraction profile for 8.2 m telescope 3e-2 8e-3 8e-4
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Detection is not Contrast !
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Detection is not Contrast (the Math) !
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Airy profile flux normalized Detection ! texp[s]0.5 A.U.1 A.U.5 A.U. 170722322 10223670771 10070712236224 1000223607071707 Sun flux @ 10pc = 1.5e9 γ/s Jupiter flux @ 10pc, 5A.U. = 5 γ/s Jupiter flux @ 10pc, 1A.U. = 125 γ/s
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Texp [s] Flux, noise [γ] 5 A.U. 0.5 A.U. 1 A.U. Detection !
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Terra, terra…. Jupiter
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Simple telescope optics: PUPIL plane IMAGE plane PUPIL plane
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Less Simple telescope optics: PUPIL plane IMAGE plane PUPIL plane OCCULTING DISK
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Lyot Coronagraph telescope optics: PUPIL plane IMAGE plane PUPIL plane OCCULTING DISK LYOT STOP
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Lyot Coronagraph gain 100 in contrast:
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Coronagraph ! texp[s]1 A.U.5 A.U.Terra 1A.U. 18741.25 102741212.5 10086639125 100027391221250 Sun flux @ 10pc = 5e9 γ/s Jupiter flux @ 10pc, 5A.U. = 5 γ/s Terra flux @ 10pc, 1A.U. = 1.3 γ/s
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Texp [s] Flux, noise [γ] 5 A.U. 1 A.U. Coronagraph Detection
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Lyot gaussian Coronagraph gain ~1e4 in contrast:
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NO OBSTRUCTION SECONDARY 11% OBSTRUCTION
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Seeing @telescope:
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Detection; FWHM size is crucial ! r=25r=15r=10 r=5 Noise level r.m.s. 33 Integral Signal 10000 S/N=4 S/N=34 S/N=1 S/N=17 S/N=0.5 S/N=11 S/N=6 S/N=? S/N [peak] S/N [integral]
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Seeing @ 8.2 m, low contrast: Flux normalized to 1 [mas] 600 mas FWHM seeing Airy profile Seeing profile FWHM=1”
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Strehl, Kolmogorov and Marechal:
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the Large Binocular Telescope Aperture diameter [m]2 x 8.4 (f# 15) Wavelenght [µm]0.32 ÷ 10 Mount controlAlt-Az on oil pad Lens profile error[nm]<50 (active and adaptive optic ) Image blurring [arcsec]0.3 ÷ 0.9 (0.015 diff. limit) Adaptive optics facility embedded in the secondary mirror LocationMount Graham (Arizona)3200 m
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the Large Binocular Telescope
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Adaptive Optics basic: MTF N.C.P.A.
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Experimental PSF (LBT FLAO results): H band[1.6µ] Esposito et al. SPIE 2011
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Strehl vs guide star (LBT FLAO results): Esposito et al. SPIE 2011
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HIP76041 750nm-10nm seeing 1” 600 modi no optics -> scale = 7.2mas/pix Ghost E. Pinna, priv. com.
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HR 8799 infrared light from ExoPlanets: Esposito et al. A&A 549, 2013
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PSF reconstruction… where are the planets here ?
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Theoretical limit for 8.2m @ 650nm (texp 3600 s + A.O. σ 80 nm + Lyot-coro) 10 pc 5 pc 1 J 4 J 10 J 50 J
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Angular Differential Imaging: RA = 0°RA = 20°RA = 45° PA = 0°PA = 20°PA = 45°
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V-SHARK-Forerunner: 600nm A.O. at 1600 f.p.s. (goal 16÷17 mas. resolution) Io moons of Jupiter Simulated image of
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V-SHARK CORONAGRAPH optical layout
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V-SHARK in 3d:
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Hot Stuff (Advanced Adaptive Optics) Adaptive Optics can work at visible; running fast, saving the errors and doing blind de-convolution you get this…! Courtesy of S. Jefferies (Maui Air Force Lab)
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No A.O. at 1.2m telescope! Applied Optics, Vol. 48, Issue 1, pp. A75-A92 (2009) http://dx.doi.org/10.1364/AO.48.000A75 Courtesy of S. Jefferies (Maui Air Force Lab)
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Is this possible….? 880 nm 3.6 meter telescope 1.22 λ/D = 61mas 10 cm @ 560 km = 36mas
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Next future LBTI vs EELT: 21 m baseline 2 x 1000÷4000 actuators Ro=13÷6 cm 37 m baseline 4000 actuators Ro=30 cm
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NGS vs LGS :
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che la Forza sia con Voi ! grazie per l’attenzione Courtesy of D. Bonaccini (ESO)
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