1. Space Infrared Astronomy in Japan 2009 UN BSS & IHY Workshop, September 22, 2009 MATSUMOTO, Toshio Seoul National University, ISAS/JAXA

2. Infrared observation is inevitable to understand the evolution of the Universe IRAS 12, 60, & 100 µm (NASA/IPAC) Most of energy is emitted in infrared Wavelength  m  –  mm  Far infrared view of ORION Thermal emission of interstellar dust is Indication of star forming activity Optical image

3. Why space infrared observation? ●Wide wavelength coverage Atmosphere is opaque in infrared region Some windows at near and mid IR FIR observation can be done only from space ●Very low background High sensitivity Absolute observation of diffuse extended sources But telescope must be cooled down!

4. Thermal emission and transparency of the atmosphere 1.0 0.0 10 -3 10 -6 10 -9 Surface brightness (W.m -2.  m -1.sr -1 ) Transparency 1 10 100 1000 Wavelength (  m) 220k Blackbody 4 km 14 km 40 km 250 km Zodiacal light IPD emission ISD emission CMB

5. Cooled telescope is necessary to utilize low background condition

6. Space infrared observation is difficult! How to keep liquid Helium at zero gravity? Separation of gas from liquid Porous plug How can we realize long life of coolant? Cryostat must survive after the shock and vibration during launch GFRP tension support cf UFURU:1970 IRAS:1983COBE, ISO, Spitzer

7. Many rocket and balloon flights (1970’ – 1980’) ● Short time scale and low cost, but limited capability short observing time (rocket) narrow wavelength coverage, high background (Balloon) ● Benefits Development of key technology for future Good training for students Must be scientifically significant ! 19 sounding rocket experiments, 13 balloon flights, 2 satellite launch

8. Balloon born liquid Nitrogen cooled telescope

9. Rocket experiment to measure infrared background with liq.He cooled telescope

10. IRTS (Infrared Telescope in Space) One of mission instruments of small space platform, SFU launched on March 15, 1995 15cm cold telescope Optimized for diffuse Extended sources Mission life ~ 1 month

11. Focal Plane Instrument NIRS (Near Infrared Spectrometer) wavelength coverage 1.4-4.0  m spectral resolution 0.13  m beam size 8 arcmin. x 8arcmin. MIRS (Mid infrared spectrometer) wavelength coverage 4.5-11.7  m spectral resolution ~0.3  m beam size 8 arcmin. x 8arcmin. FILM (Far-Infrared Line mapper) wavelength coverage 158(CII) and 63 (OI)  m spectral resolution  /  ~ 400 beam size 8 arcmin. x 13 arcmin. FIRP (Far-Infrared Photometer) wavelength coverage 150-700  m spectral resolution  /  ~ 3 beam size 8 arcmin. x 13 arcmin. detector temperature 0.3K

12. IRTS detected excess emission that could be pop.III origin

13. Based on the success of IRTS, we proposed dedicated infrared astronomical satellite to ISAS, ASTRO-F (AKARI), on 1995 ASTRO-F ●70 cm aperture, liq.He cooled telescope ●Survey mission, higher sensitivity and better spatial resolution longer wavelength band (200  m) than IRAS

14. Advanced space cryogenics Effective use of radiative cooling 2-stage Stirling Cooler Life time of liquid Helium 550 days with 170 liter Liq. He c ｆ. IRAS and COBE 10 months with 600 liter Liq. He

15. Satellite system

16. AKARI, Focal Plane Instrumnets IRC(Infrared Camera) 512x412 InSb array camera, 1.5”/pixel imaging observation at 2.4, 3.2, and 4.1 mm low resolution spectroscopy 256x256 SiAs array, 2.4”/pixel imaging observation at 7~24 mm low resolution spectroscopy FIS(Far Infrared Surveyor) all sky survey with 4 bands from 50 – 200  m Fourier spectroscopy

17. ASTRO-F was launched on February 22, 2006, and named as “AKARI” Orbit : sun synchronous orbit, 705 km altitude Liq. He ran out on August 2007 Near infrared observation is still being continued (phase 3) owing to cooler http://www.ir.isas.jaxa.jp/ASTRO-F/Observation/

19. Far infrared image of reflection nebulae IC4954

20. Star forming region observed with AKARI Visible light AKARI 9 & 18  m Credit: Davide De Martin (http://www.skyfactory.org/), ESA/ESO/NASA FITS Liberator & Digitized Sky Surveyhttp://www.skyfactory.org/ Reflection nebulae IC1396

21. Large Megellanic Cloud Visible light

22. Near and mid infrared image observed with AKARI AKARI 3, 7, & 11 µm

23. Far infrared image of LMC observed with AKARI AKARI 65, 90, & 140 µm

24. AKARI detected fluctuation of sky brightness which could be pop.III origin 2.4  m 3.2  m 4.1  m

25. 90% of the whole sky was surveyed ~880,000 sources are detected

26. AKARI-FIS BSC  -2 PRELIMINARY WIDE-S (90 µm) 284,633 sources First point source catalogue will be opened to public in next spring

27. Next mission after AKARI? Space observation is very sensitive, but angular resolution is not so good compared with optical and radio due to the diffraction limit. /D ~ 30 arcsec, at 100  m for AKARI It is too heavy to install large aperture telescope for the traditional space infrared mission (IRAS, ISO, AKARI). New idea is required!

28. No cryogen, warm launch Cooled down in space with mechanical cooler Effective radiation cooling at L2 orbit -> SPICA Space Infrared Telescope for Cosmology and Astrophysics

29. Outline of SPICA To reveal the history of Universe through Infrared Observations Telescope: 3.5m, 4.5 K HSO: 3.5m, 80K JWST: ~6m, <50K Core λ: 5-200 μm MIR imaging, spectroscopy FIR imaging, spectroscopy (SAFARI) NIR, MIR coronagraph (option) NIR camera (FPC, option) Orbit: Sun-Earth L2 Halo Warm Launch, Cooling in Orbit No Cryogen SPICA is now pre-project phase Final approval will be on 2010 fall Launch: ～ 2017

33. SPICA will be opened to world wide community We welcome participation of other countries focal plane instruments Development of software Satellite operation Observation and science Open time to general community (~20%) is planned Contact person: nakagawa@ir.isas.jaxa.jp

35. AKARI Point Source Catalogue(s) MIR FIR  -2 Wavelength (µm) 9, 1865, 90, 140, 160 Number of sources ~880,000284,633 Detection limit 50 & 130 mJy0.5~ 7 ~ 13 Jy Photometric uncertainty 7–15 %30 ~ 50 % Spatial resolution ~10 arcsec~1 arcmin Position uncertainty 1–3 arcsec4–5 arcsec First point source catalogue will be opened to public in next spring