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An Instrument Concept Study for OWL Multi-Object, Multi-Field Ir Spectrograph

An Instrument Concept Study for OWL Multi-Object, Multi-Field Ir Spectrograph. OWL-MOMFIS. Institutes: Laboratoire d’Astrophysique de Marseille (LAM) GEPI, Observatoire Paris-Meudon LESIA, Observatoire Paris-Meudon Centre de Recherche Astronomique de Lyon (CRAL) ONERA Main contributors:

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An Instrument Concept Study for OWL Multi-Object, Multi-Field Ir Spectrograph

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  1. An Instrument Concept Studyfor OWLMulti-Object, Multi-Field Ir Spectrograph OWL-MOMFIS MOMFIS

  2. Institutes: • Laboratoire d’Astrophysique de Marseille (LAM) • GEPI, Observatoire Paris-Meudon • LESIA, Observatoire Paris-Meudon • Centre de Recherche Astronomique de Lyon (CRAL) • ONERA • Main contributors: • Eric Prieto (PM), J.-P. Kneib (science case), P.-E. Blanc, J.-G. Cuby (PI) (LAM) • F. Hammer, M. Marteaud, P. Vola, P. Jagourel (OPM) • Collaboration to continue on ELT-Design Study • ESO contact: M. Casali Collaborations MOMFIS

  3. Science Case The ‘faint objects, near IR’ cosmology case… The End of the Dark Ages: First Light and Reionization (JWST SRD, E-ELT Opticon science case, TMT, GMT, SKA, etc.) • Nature of the first objects: popIII stars, BHs, AGNs,… • N(z), SFR(z), 〈Z〉(z), etc • How did they re-ionize the Universe ? • Mass Assembly of the galaxies Nick Gnedinhttp://casa.colorado.edu/~gnedin MOMFIS

  4. Number counts z = 6 JWST Science Req. Document Dz = 1 MOMFIS

  5. Complementarity with JWST OWL spectro 10ksec MOMFIS

  6. Performance J =28-29, R=4000 MOMFIS

  7. High level science specs MOMFIS

  8. MOMFIS

  9. Concept steering mirror instrument DM Pick-off mirror • F/6 input beam • Spherical Pick-off mirrors • Active Toroidal steering mirrors: • z translation • Rot: x,y,z • Curvature radius adaptation • Feed to fixed optics: • DM • Slicers • Spectrographs MOMFIS

  10. Conceptual Design WFS Beam steering mirror Slicer unit 3 spectrographs 1 cryostat ADC MOMFIS

  11. Spectrograph • F/1.8 camera • Detector: 2kx2k, 18 mm pixels • 150 mm pupil MOMFIS

  12. Cryostats • 900 Kg / cryostat • 190 LN2 l/day/unit • or 3-4 CCC f 760 mm Volume: 1,4m3 2300 mm f760 mm 1700 mm MOMFIS

  13. Beam Steering Mirrors Optical surface (metallic) Piezo actuator blocked Displacement probes Piezo actuator activated FEA model Zemax  Zernike polynomials Dz data file MOMFIS

  14. Mechanics 4.5 m Cable wrap Safety brake • Bearing Ø 4.5 m. Feasible (ROLLIX). Cost estimate: 60 kEuros • Motor. Feasible (ARTUS) Need specific development : 50KEuros Cost between 50 & 75 kEuros • Encoder. (HEIDENHAIM) Std tape (10m) allows ~ 270° encoding. Rotator implementation: MOMFIS

  15. Mechanics: FEA analysis Steering mirrors Corrector Carbon/epoxy Focal plate: carbon/epoxy + Iron Platform: steel Cryostats: stainless steel The mass of spectrograph composite structure is 3000 kg. At equivalent stiffness, the gain vs steel or Al is a factor 2 to 2.5. MOMFIS

  16. Flexures • The order of magnitude of flexures (for any 60° rotation of telescope) is: 1°- Translations: 100 µm. 2°- Rotations: 50 µrad. • The first eigen frequency of this structure is 36 Hz. MOMFIS

  17. Internal metrology instrument Dichroic Sensor DM Pick-off miroir • Artificial source at pick-off mirror level • Trough BSM and DM • Dichroic & WFS before instrument • Sensor: • WFE • Tip-Tilt • Defocus MOMFIS

  18. Positioner (a la OzPoz) MOMFIS

  19. Overall implementation MOMFIS

  20. MOAO 200 x 200 100 x 100 50 x 50 • Constellation of 3 NGS • Encircled energy in 50 mas pixels • H band 100 x 100 14 ESO Simulations (Le Louarn et al.) 15 16 MOMFIS

  21. MOAO Sky coverage ESO MOMFIS

  22. Conclusions #1 • Conceptual design meets science specs • Improve design (e.g. positioner, starbugs, hexapods for BSM) • Reduce weight (currently factor ~2 above spec) • Design relies on existing technologies, no critical development items (but for AO) • R&D activities continue in Opticon / ELT DS FP6 programmes: steering mirrors, slicers, metrology, etc. • MOAO: • Further studies required to demonstrate concept, open loop operation, etc. • Rely on AO developments done elsewhere (DMs, WFS) • Phasing with OWL-AO development plan (GLAO, MCAO) MOMFIS

  23. Conclusions #2 • Fallback operation: GLAO, MCAO on a smaller field • Phased implementation: • Start with GLAO • Continue with MCAO • Implement MOAO in a 2nd/3rd phase • Redundancy / modularity (e.g. one extra-cryostat) : maintainability • Growing telescope: ‘just’ a matter of pupil stops ? MOMFIS

  24. Conclusions #3 • Development time: • ~ 4 yrs to PDR, including phase A & breadboarding • ~ 6 yrs from PDR to first light • Cost: • 30 – 40 M€ • 300 FTEs minimum • Requires multi-institute partnerships, large integration/testing facilities, etc. MOMFIS

  25. Conclusion #4: Feedback to ESO/OWL • Big diameter helps the science case • Consider 60 being as overwhelming as 100 • Include MOAO & LGS in system analysis • Adapter/rotator (2 tons) not usable • Active and adaptive WFS gone, but instrument can provide alternative ones • Weight spec (17 tons) likely too strict • Handling & integration in focal station is a concern • Non gravity stable platform : can be dealt with but adds complexity to instrument (metrology & control) MOMFIS

  26. MOMFIS

  27. Today state of the Art: UDF-NICMOSBouwens et al 2004 MOMFIS

  28. Today state of the Art: Cluster lensesEllis et al 2001, Kneib et al 2004, Egami et al 2004 MOMFIS

  29. Today state of the Art: spectroscopy 920 R I B V Det MOMFIS

  30. High redshift galaxy size ~0.1” Bouwens et al 2004 MOMFIS

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