1 / 21

Technologies for Future Far-IR Telescopes and Interferometers

Dave Leisawitz, NASA GSFC. Technologies for Future Far-IR Telescopes and Interferometers. SPIRIT. CALISTO. SPICA. Future Far-IR Missions. SPICA – the Space Infrared Telescope for Cosmology and Astrophysics, led by Japan

dreama
Download Presentation

Technologies for Future Far-IR Telescopes and Interferometers

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Dave Leisawitz, NASA GSFC Technologies for Future Far-IR Telescopes and Interferometers SPIRIT CALISTO SPICA

  2. Future Far-IR Missions • SPICA – the Space Infrared Telescope for Cosmology and Astrophysics, led by Japan • SPIRIT – the Space Infrared Interferometric Telescope, studied as a candidate Origins Probe (comparable to FIRI – the Far-Infrared Interferometer in Europe) • SAFIR – Single Aperture Far-IR Telescope. A refined version,CALISTO, the Cryogenic Aperture Large Infrared Space Telescope Observatory, was proposed for technology devopmentto the Decadal Survey The Far-IR Community is unified in its endorsement of US involvement in these missions. D. Leisawitz - COPAG Workshop - Austin AAS 219

  3. NWNH Recommendations • Science goals that require more capable far-IR missions than any developed to date • US participation in SPICA (budget caveat) • Technology development for single-aperture (SAFIR/CALISTO) and interferometric (SPIRIT) far-IR missions D. Leisawitz - COPAG Workshop - Austin AAS 219

  4. Compelling Science Goals • How do the conditions for planetary habitability arise during planet formation? (“follow the water”) • Find and characterize exoplanets by imaging and measuring the structures in protoplanetary and debris disks. • How did high-redshift galaxies form and merge to form the present-day population of galaxies? (How did a hot, smooth universe give rise to the Milky Way?) • When and how did the first stars form and enrich the intergalactic medium? SPIRIT SAFIR/ CALISTO D. Leisawitz - COPAG Workshop - Austin AAS 219

  5. Water, water everywhere! (Some gaseous, some solid.) How do the conditions for planet habitability arise during planet formation? D. Leisawitz - COPAG Workshop - Austin AAS 219

  6. Find and characterize planets by detecting lumps of gravitationally trapped dust in debris disks. Kuchner et al. EpsEri model scaled to 30 pc Detect and characterize newborn planets in protoplanetary disks. Jang-Condell protoplanetary disk structure D. Leisawitz - COPAG Workshop - Austin AAS 219 14 May 2011 D. Leisawitz - Far-IR Space Opportunities and SPIRIT 6

  7. How did high-z galaxies form and merge to form the present-day population of galaxies? D. Leisawitz - COPAG Workshop - Austin AAS 219

  8. Herschel GOODS-N Deep Field D. Leisawitz - COPAG Workshop - Austin AAS 219

  9. Derived Requirements (SPIRIT) • Sub-arcsecond angular resolution over the wavelength range 25 – 400 mm (between JWST and ALMA) • Image protostellar and debris disks • Resolve the far-IR extragalactic background • ~10 mJy continuum, 10-19 W/m2 line sensitivity • Detect low surface brightness debris disks • Measure SEDs and spectral lines of high-z galaxies • >1 arcmin instantaneous FOV • Spectral resolution, R ~ 3000 (integral field spectroscopy) D. Leisawitz - COPAG Workshop - Austin AAS 219

  10. To image protoplanetaryand debris disks and definitively distinguish the emissions of individual high-z galaxies requires sub-arcsecond angular resolution. This capability is sorely lacking in the far-IR, where these objects are bright and their information content is great. D. Leisawitz - COPAG Workshop - Austin AAS 219

  11. Measurement requirements drive technology requirements Sub-arcsecond angular resolution Astronomical background-limited sensitivity • Technology: • Detectors • Cryocoolers • Wide-field spatial-spectral interferometry • Low aereal density, possibly deployable primary mirror D. Leisawitz - COPAG Workshop - Austin AAS 219

  12. Technology Roadmap (SPIRIT)* * A large single-aperture telescope also requires: large format, lower NEP detectors, though they needn’t be as fast (see Paul Goldsmith’s presentation), and a low aereal density primary mirror, possibly deployable. D. Leisawitz - COPAG Workshop - Austin AAS 219

  13. Cooling FIR Telescopes: Past and Future Past: • IRAS • COBE • Spitzer • Akari • WISE • Herschel Future: • SPICA • SAFIR/CALISTO • SPIRIT Past missions used expendable cryogens Future missions will use cryocoolers D. Leisawitz - COPAG Workshop - Austin AAS 219

  14. Why use cryocoolers? • Much less mass to launch • Greatly reduced volume relative to cryostat • Lower mass and volume means lower cost to launch or more room for science payload • Mission lifetime not limited by expendable cryogen D. Leisawitz - COPAG Workshop - Austin AAS 219

  15. Technology Readiness With straightforward modifications, the JWST cryocooler(left) and the IXO CADR (right) will reach TRL 6 for SPIRIT. D. Leisawitz - COPAG Workshop - Austin AAS 219

  16. How much cooling power? (Left) Heat loads and cryocoolerrequirements are based on high-fidelity thermal models like this 106-node model of a SPIRIT telescope. (Right) Subscale cryothermaltesting in a LHe shroud was used to validate the model. Dipirro et al. (2007) D. Leisawitz - COPAG Workshop - Austin AAS 219

  17. Cooling Requirements (SPIRIT)* • For optical components, extend JWST cryocooler technology to enable cooling to 4 K with 180 mW heat lift at 18 K and 72 mW at 4K. • For focal plane, need an ADR cryocooler operating from a base temperature of ~4K and cooling to 30 mK with a continuous heat lift of 5µW at 50 mK and 1 mW at 30 mK. • Compactness, high efficiency, low vibration, and other impact-reducing design aspects are desired. * More stringent requirements may pertain to a large single-aperture far-IR telescope with much larger focal plane arrays. D. Leisawitz - COPAG Workshop - Austin AAS 219

  18. Wide-field Spatial-Spectral Interferometrysomething old and something new D. Leisawitz - COPAG Workshop - Austin AAS 219

  19. Wide-field Spatial-Spectral interferometry We’ve been developing and gaining practical experience with this technique in the lab for the past decade D. Leisawitz - COPAG Workshop - Austin AAS 219

  20. Low aereal density mirror CALISTO ~10 kg/m2 ~4 K D. Leisawitz - COPAG Workshop - Austin AAS 219

  21. Summary • In the far-IR, the drive toward sub-arcsecond angular resolution coupled with the need for astronomical background-limited sensitivity translates into technology requirements for: • Far-IR detectors (Paul Goldsmith’s presentation) • Cryocoolers • Wide-field spatial-spectral interferometry • Low aereal density mirrors • Most of the technology requirements are well understood • Recommendation: future investments in the technologies listed above should be coordinated, sustained, and tied to the needs of studied single aperture and interferometric mission concepts D. Leisawitz - COPAG Workshop - Austin AAS 219

More Related