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Key Types Introduction

Key Types Introduction. Wesley A. Traub Harvard-Smithsonian Center for Astrophysics. Michelson Summer School on High-Contrast Imaging Caltech, Pasadena 20-23 July 2004. Reminders of main topics. C, IWA, OWA types perturbations. C. K~20 mag Bkgd objects. 7 arcsec wand. J~21 mag

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Key Types Introduction

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  1. Key Types Introduction Wesley A. Traub Harvard-Smithsonian Center for Astrophysics Michelson Summer School on High-Contrast Imaging Caltech, Pasadena 20-23 July 2004

  2. Reminders of main topics • C, IWA, OWA • types • perturbations

  3. C K~20 mag Bkgd objects 7 arcsec wand J~21 mag Bkgd object 20 arcsec radius circle Ref: McCarthy & Zuckerman (2004); Macintosh et al (2003)

  4. Search space: best to date Keck IRCAL, Lick AO, K Ks, AO, NACO, VLTI WFPC2, HST, I CFHT, AO, H Keck NICMOS, 10sig 50% det, HST, H XAO, 10m, R, 2007 Airy Halo

  5. Earth & Jupiter-Saturn, 100 stars Simulations by Bob Brown, STScI

  6. Earth & Jupiter-Saturn Regions

  7. Radial-velocity Stars

  8. RV stars and brown dwarfs

  9. 1.8-m range

  10. TPF-C Range

  11. C, IWA, OWA Contrast C: Example: C = 10-10 driven by Earth/Sun = 2x10-10. Inner working angle IWA: Example: IWA = 3 /D driven by 1 AU/10pc = 0.100 arcsec. Outer working angle OWA: Example: OWA = 48 /D driven by N = 96 actuator DM.

  12. Image-plane coronagraph simulation 1st image with Airy rings mask, centered on star image 1st pupil 2nd pupil Lyot stop, blocks bright edges 2nd image, no star, bright planet Ref.: Pascal Borde 2004

  13. Wide-band (quadrant-phase) mask

  14. y v Shaped-pupil mask x u Image: cut along the x-axis Pupil: Spergel-Kasdin prolate-spheroidal mask Image: dark areas < 10-10 transmission A(x, 0) = exp(-(x/)2) A(0, y) = periodic & messy Kasdin, Vanderbei, Littman, & Spergel, preprint, 2004

  15. Discrete-mapped pupil (2): Densification Clean image, narrow FOV Image with many aliases Densified pupil Entrance pupil, sparsely filled FOV is small.

  16. Continuous-mapped pupil Input wavefront: uniform amplitude. Mirror 2 100 dB = 10-10 = 25 mag Output wavefront: prolate-spheroidal amplitude. Output image: prolate spheroid Mirror 1 Compact star image, easily blocked

  17. Nulling-shearing coronagraph

  18. Phase ripple and speckles Polishing errors on primary Pupil plane Phase ripples from primary mirror errors Speckles generated by 3 sinusoidal components of the polishing errors No DM: Image plane With DM: Image plane

  19. Phase + amplitude ripple and speckles h(u) = n (an+ian')cos(Knu) + (bn+ibn')sin(Knu) = total ripples Describes all possible phase and amplitude ripples (= errors). DM can give I() = (0) + n [(bn’)2 + (an’)2 ] (k+Kn)  bigger speckles + [ 0 + 0 ] (k-Kn)]  smaller (zero) speckles

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