SOFIA Stratospheric Observatory for Infrared Astronomy

1. SOFIAStratospheric Observatory for Infrared Astronomy R. D. Gehrz Lead, SOFIA Community Task Force (SCTF) Department of Astronomy, University of Minnesota Astronomy and Astrophysics Advisory Committee, October 12, 2007

2. Outline • SOFIA Science • Description of the Observatory and Project Status • Schedule • Summary Astronomy and Astrophysics Advisory Committee, October 12, 2007

3. Science Astronomy and Astrophysics Advisory Committee, October 12, 2007

4. Key Science Topics Related to Origins • How stars form in our galaxy and other nearby galaxies • Chemistry, Mineralogy, and Biology • Solar System studies • Targets of Opportunity, for example: • Bright Comets • Eruptive variable stars • Galactic and LMC/SMC classical novae • Supernova in our galaxy or other nearby galaxies • Eclipses and Occultations in the Solar System Astronomy and Astrophysics Advisory Committee, October 12, 2007

5. SOFIA and the Chemical Evolution of the Universe Astronomy and Astrophysics Advisory Committee, October 12, 2007

6. The Advantages of SOFIA • Above 99% of the water vapor • Transmission at 14 km >80% from 1 to 800 µm; emphasis on the obscured IR regions • Instrumentation: wide variety, rapidly interchangeable, state-of-the art • Mobility: anywhere, anytime • Twenty year design lifetime • A near-space observatory that comes home after every flight Astronomy and Astrophysics Advisory Committee, October 12, 2007

7. Unique Science Capabilities • 8 arcmin diameter FOV allows use of very large detector arrays • Image size is diffraction limited beyond 15 µm, making images 3 times sharper than Spitzer Space Telescope • Because of large aperture and better detectors, sensitivity for imaging and spectroscopy will be similar to the space observatory ISO • Ability to adapt to new technologies • Ability to track temporal events Astronomy and Astrophysics Advisory Committee, October 12, 2007

8. Expectations for Improvements in Detectors Due to increases sensitivity and the number of pixels in large format IR detectors, the speed of measurement has doubled every year for the last 40 years Astronomy and Astrophysics Advisory Committee, October 12, 2007

9. Most ground state molecular lines in IR or submillimeter Need high spectral resolution throughout which SOFIA has. As sensitive as CSO, but much larger wavelength range is accessible Light molecules: Molecular hydrogen, HD, water, other hydrides in IR and submillimeter The fullerene, C60, has 4 IR lines in SOFIA’s bands Astrochemistry SOFIA is a good observatory for studying chemistry in space CSO FTS Spectrum of ORION OMC1 Serabyn and Weisstein 1995 Astronomy and Astrophysics Advisory Committee, October 12, 2007

10. Occultation astronomy with SOFIA SOFIA will determine the properties of Dwarf Planets in and beyond the Kuiper Belt Pluto occultation lightcurve observed on the KAO (1988) probes the atmosphere • SOFIA can fly anywhere on the Earth, allowing it to position itself under the shadow of an occulting object. • Occultation studies with SOFIA will probe the sizes, atmospheres, and possible satellites of newly discovered planet-like objects in the outer Solar system. • The unique mobility of SOFIA opens up some hundred events per year for study compared to a handful for fixed observatories. Astronomy and Astrophysics Advisory Committee, October 12, 2007

11. Today over 200 extrasolar planets are known, and over 15 transit their primary star: SOFIA will fly above the scintillating component of the atmosphere and will provide the most sensitive freely pointing observatory for extrasolar planetary transits after HST and before JWST. SOFIA has instruments that can observe with high signal-to-noise the small variations in stellar flux due to a planet transit and Provide good estimates for the mass, size and density of the planet May reveal the presence of, satellites, and/or planetary rings Extrasolar Planet Transits SOFIA will determine the properties of new extrasolar planets by use of transits with HIPO and FLITECAM working together Artist concept of planetary transit and the lightcurve of HD 209458b measured by HST revealing the transit signature Astronomy and Astrophysics Advisory Committee, October 12, 2007

12. Clues to the evolution of galaxies: starbursts triggered by collisions and star formation in low-metallicity environments NASA/JPL-Caltech/V. Gorjian NASA/JPL-Caltech/Z. Wang Henize 206- LMC high mass star formation MIPS @ 24 mm (80s, 20’ x 20’) HAWC Fields of view (Current 12x32 array at 53, 89, 155, 216 m; Circle is total optical FOV) Antennae Galaxies IRAC @ 8 mm (red; 160s, 4’ x 4’) HAWC Beam Sizes Astronomy and Astrophysics Advisory Committee, October 12, 2007

13. Cold Molecular Hydrogen using HD SOFIA will study deuterium in the galaxy using the ground state HD line at 112 microns. This will allow determination the cold molecular hydrogen abundance. Atmospheric transmission around the HD line at 40,000 feet • Deuterium in the universe is created in the Big Bang. • Measuring the amount of cold HD (T<50K) can best be done with the ground state rotational line at 112 microns. • A GREAT high resolution spectrometer study is possible given ISO detection • HD traces the cold molecular hydrogen (Bergen and Hollenbach). • HD has a much lower excitation temperature and a dipole pole moment that almost compensates for the higher abundance of molecular hydrogen. • In the future, this technique could be used much like the HI 21cm maps but for cold molecular gas. Astronomy and Astrophysics Advisory Committee, October 12, 2007

14. Classical Nova Explosions Astronomy and Astrophysics Advisory Committee, October 12, 2007

15. Spitzer Spectra of Nova V382 Vel R. D. Gehrz, et al. 2005, ApJ, in preparation [PID 124] H I [Ne II] [Ne V] [Ne III] [O IV] [Ne III] [Ne V] IRS Long-High IRS Short-High IRS Short and Long-High Spectra: Abundances and Kinematics Astronomy and Astrophysics Advisory Committee, October 12, 2007

16. SOFIA’s Instrument Complement • As an airborne mission, SOFIA supports a unique, expandable instrument suite • SOFIA covers the full IR range with imagers and low, moderate, and high resolution spectrographs • 4 instruments at IOC; 9 instruments at FOC • SOFIA can take full advantage of improvements in instrument technology • Both Facility and PI Instruments Astronomy and Astrophysics Advisory Committee, October 12, 2007

17. 8 10 7 10 Planetary Atmospheres Chemistry of the cold ISM 6 Dynamics of collapsing protostars 10 Comet Molecules Dynamics of the Galactic Center 5 10 Velocity structure and gas composition in disks and outflows of YSOs 4 Composition/dynamics/physics of the ISM in external galaxies 10 Spectral resolution PAH & organic molecules 3 10 Nuclear synthesis in supernovae in nearby galaxies Composition of interstellar grains 2 10 Debris Disk Structure KBOs, Planet Transits Luminosity and Morphology of Star Formation Galactic and Extra-Galactic Regions 1 10 0 10 1 10 100 1000 Wavelength [µm] SOFIA: Science For the Whole Community Astronomy and Astrophysics Advisory Committee, October 12, 2007

18. 8 10 7 10 6 GREAT 10 5 10 CASIMIR EXES 4 Spectral resolution 10 3 FLITECAM 10 FIFI LS SAFIRE 2 10 HIPO FORCAST 1 10 HAWC 0 10 1 10 100 1000 Wavelength [µm] SOFIA Performance: Spectral Resolution of the First Generation Science Instruments • FORCAST • SPITZER IRS MIPS IRAC Astronomy and Astrophysics Advisory Committee, October 12, 2007

19. Astronomy and Astrophysics Advisory Committee, October 12, 2007

20. Infrared Space Observatories 1000 0.3 ? SAFIR Frequency (THz) Herschel SOFIA 100 3 JWST SPITZER Wavelength (µm) 10 30 1 2005 2010 2015 2020 2025 Ground-based Observatories SOFIA provides temporal continuity and wide spectral coverage, complementing other infrared observatories. Astronomy and Astrophysics Advisory Committee, October 12, 2007

21. Overview Astronomy and Astrophysics Advisory Committee, October 12, 2007

22. SOFIA Overview • 2.5 m (98 inch) telescope in a modified Boeing 747SP aircraft • Optical to millimeter-wavelengths • Emphasis on the obscured IR (30-300 m) • Operating altitude • 39,000 to 45,000 feet (12 to 14 km) • Above > 99% of obscuring water vapor • Joint Program between the US (80%) and Germany (20%) • First Light Science 2009 • 20 year design lifetime • Science Ops at NASA-Ames and Flight Ops at NASA-Dryden • Deployments to the Southern Hemisphere and elsewhere • >120 8-10 hour flights per year • Built on NASA Lear/Kuiper Airborne Observatory Heritage Astronomy and Astrophysics Advisory Committee, October 12, 2007

23. Astronomy and Astrophysics Advisory Committee, October 12, 2007

24. M2 Pressure bulkhead Spherical Hydraulic Bearing Focal Plane M3-1 Nasmyth tube M3-2 Primary Mirror M1 Focal Plane Imager Nasmyth: Optical Layout Astronomy and Astrophysics Advisory Committee, October 12, 2007

25. The Un-Aluminized Primary Mirror Installed Astronomy and Astrophysics Advisory Committee, October 12, 2007

26. Four First Light Instruments Working/complete HIPO instrument in Waco on SOFIA during Aug 2004 Working/complete FLITECAM instrument at Lick in 2004/5 Working FORCAST instrument at Palomar in 2005 Successful lab demonstration of GREAT in July 2005 Astronomy and Astrophysics Advisory Committee, October 12, 2007

27. Status Astronomy and Astrophysics Advisory Committee, October 12, 2007

28. SOFIA Airborne! 26 April 2007, L-3 Communications, Waco Texas: SOFIA takes to the air for its first test flight after completion of modifications Astronomy and Astrophysics Advisory Committee, October 12, 2007

29. Early Science with SOFIA • The aircraft has flown in April 2007 and is now at NASA Dryden FRC for flight certification tests • Early Science is expected to occur in 2009 • Two instruments have been selected for Early Science - FORCAST: a US 5-40 μm imager - GREAT: a German heterodyne 60 to 200 μm Spectrometer - Both have been tested in the lab or on a telescope Astronomy and Astrophysics Advisory Committee, October 12, 2007

30. Summary • Program making progress! • Aircraft structural modifications complete • Telescope installed, several instruments tested on ground observatories • Completed first flight and ferry flight to NASA Dryden • Full envelope flight testing (closed door) has started. • Several subsystems will be installed spring/summer 08 (Door motor drive, coated primary mirror) • First science in ’09 • SOFIA will be one of the primary facilities for far-IR and sub-millimeter astronomy for many years Astronomy and Astrophysics Advisory Committee, October 12, 2007

31. Schedule Astronomy and Astrophysics Advisory Committee, October 12, 2007

32. SOFIA Schedule (Major Milestones) • First Re-Flight Occurred April ’07 • Door Drive Delivered Winter ’07 • Open Door Flights at DFRC Fall ’08 • First Science ‘09 • Next Instrument call ‘10 Astronomy and Astrophysics Advisory Committee, October 12, 2007

33. US General Observer Opportunities • First call for science proposals in ’09 • Future calls every 12 months • First General Observers 2010 • Expect ~ 20 General Observer science flights • Shared risk with Instrument PI’s • Open Observatory with Facility Instruments Astronomy and Astrophysics Advisory Committee, October 12, 2007

34. Next Call For New Instruments • The next call for instruments will be at first Science ~FY10 • There will be additional calls every 3 years • There will be one new instrument or upgrade per year • Approximate funding for new instruments $8 M/yr Astronomy and Astrophysics Advisory Committee, October 12, 2007

35. Summary • SOFIA has unique spectral and temporal coverage • Unique high-resolution spectroscopy: 28 < l < 150 μm • (l/10 μm) arc-sec image quality, unique for 30 < l < ~60 μm • Unique ability to obtain coverage of transient events • Unique long operating lifetime • SOFIA will increase its unique complement of capabilities in the future and will be a test-bed of technologies for future Far-IR missions • State-of-the-art large format IR detector arrays • Polarimeteric imaging and spectroscopy • SOFIA is a hands-on Far-IR observatory • Will train future mission scientists and instrumentalists • SOFIA is on track for first science in 2009 Astronomy and Astrophysics Advisory Committee, October 12, 2007

36. Appendix Astronomy and Astrophysics Advisory Committee, October 12, 2007

37. The Initial SOFIA Instrument Complement • HIPO: High-speed Imaging Photometer for Occultation • FLITECAM: First Light Infrared Test Experiment CAMera • FORCAST: Faint Object InfraRed CAmera for the SOFIA Telescope • GREAT: German Receiver for Astronomy at Terahetz Frequencies • CASIMIR: CAltech Submillimeter Interstellar Medium Investigations Receiver • FIFI-LS: Field Imaging Far-Infrared Line Spectrometer • HAWC: High-resolution Airborne Wideband Camera • EXES: Echelon-Cross -Echelle Spectrograph • SAFIRE: Submillimeter And Far InfraRed Experiment Astronomy and Astrophysics Advisory Committee, October 12, 2007

38. SOFIA’s 9 First Generation Instruments 4.5-28.3 * Listed in approximate order of expected in-flight commissioning % Operational (August 2004) § Uses non-commercial detector/receiver technology Astronomy and Astrophysics Advisory Committee, October 12, 2007 Science

39. Science Objectives • Major Science Programs for SOFIA: • Origin of stars and planetary systems • Planetary bodies that make up our Solar System • Life-cycle of dust and gas in galaxies • Composition of the molecular universe • Role of star formation and black hole activity in the energetics of luminous galaxies • SOFIA has a unique suite of instruments that cover a wide range of wavelengths at a wide range of spectral resolution. • SOFIA will be continuously upgraded with new instrumentation and will serve as an important technology development platform for future space missions. • SOFIA is a highly visible icon for education and public outreach and will immerse educators in the scientific process. Astronomy and Astrophysics Advisory Committee, October 12, 2007

40. Learjet-KAO Instrumentalists and their Contributions Astronomy and Astrophysics Advisory Committee, October 12, 2007

41. Great Observatory Operations Costs for FY 08 • CONCLUSIONS • SOFIA’s total operating costs are comparable to those of • the other Great Observatories • SOFIA has fewer operating hours (it’s an airplane) • SOFIA’s costs include servicing missions with new focal • plane instruments every few years Astronomy and Astrophysics Advisory Committee, October 12, 2007

42. Courtesy of Gary Melnick Astronomy and Astrophysics Advisory Committee, October 12, 2007

43. Courtesy of Gary Melnick Astronomy and Astrophysics Advisory Committee, October 12, 2007