340 likes | 521 Views
Space Infrared Astronomy in Japan. 2009 UN BSS & IHY Workshop, September 22, 2009 MATSUMOTO, Toshio Seoul National University, ISAS/JAXA. Infrared observation is inevitable to understand the evolution of the Universe. Most of energy is emitted in infrared Wavelength (1m m – 1 mm )
E N D
Space Infrared Astronomy in Japan 2009 UN BSS & IHY Workshop, September 22, 2009 MATSUMOTO, Toshio Seoul National University, ISAS/JAXA
Infrared observation is inevitable to understand the evolution of the Universe Most of energy is emitted in infrared Wavelength (1mm – 1mm) Far infrared view of ORION Thermal emission of interstellar dust is Indication of star forming activity Optical image IRAS 12, 60, & 100 µm (NASA/IPAC)
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!
Thermal emission and transparency of the atmosphere 40 km 1.0 0.0 10-3 10-6 10-9 14 km 4 km 220k Blackbody Surface brightness (W.m-2.mm-1.sr-1) Transparency Zodiacal light 250 km IPD emission CMB ISD emission 10 100 1000 Wavelength (mm)
Cooled telescope is necessary to utilize low background condition
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 GFRPtension support cf UFURU:1970 IRAS:1983 COBE, ISO, Spitzer
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
Rocket experiment to measure infrared background with liq.He cooled telescope
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
Focal Plane Instrument NIRS (Near Infrared Spectrometer) wavelength coverage 1.4-4.0 mm spectral resolution 0.13 mm beam size 8 arcmin. x8arcmin. MIRS (Mid infrared spectrometer) wavelength coverage 4.5-11.7mm spectral resolution ~0.3 mm beam size 8 arcmin. x 8arcmin. FILM (Far-Infrared Line mapper) wavelength coverage 158(CII) and 63 (OI) mm spectral resolution l/Dl~ 400 beam size 8 arcmin. x 13 arcmin. FIRP (Far-Infrared Photometer) wavelength coverage 150-700 mm spectral resolution l/Dl~ 3 beam size 8 arcmin. x 13 arcmin. detector temperature 0.3K
Based on the success of IRTS, we proposed dedicated infrared astronomical satellite to ISAS, ASTRO-F (AKARI), on 1995ASTRO-F●70 cm aperture, liq.He cooled telescope●Survey mission, higher sensitivity and better spatial resolution longer wavelength band (200mm) than IRAS
Advanced space cryogenics • Effective use of radiative cooling • 2-stage Stirling Cooler • Life time of liquid Helium • 550 days with 170 liter Liq. He • cf. IRAS and COBE • 10 months with 600 liter Liq. He
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 SiAsarray, 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 mm Fourier spectroscopy
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/
AKARI 9 & 18 mm Star forming region observed with AKARI Reflection nebulae IC1396 Visible light Credit: Davide De Martin (http://www.skyfactory.org/), ESA/ESO/NASA FITS Liberator & Digitized Sky Survey
Large Megellanic Cloud Visible light
Far infrared image of LMC observed with AKARI AKARI 65, 90, & 140 µm
AKARI detected fluctuation of sky brightness which could be pop.III origin 2.4mm 3.2 mm 4.1 mm
90% of the whole sky was surveyed • ~880,000 sources are detected
AKARI-FIS BSC b-2 WIDE-S (90 µm) Preliminary 284,633 sources • First point source catalogue will be opened to public in next spring
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. l/D ~ 30 arcsec, at 100 mm for AKARI It is too heavy to install large aperture telescope for the traditional space infrared mission (IRAS, ISO, AKARI). New idea is required!
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
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
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
AKARI Point Source Catalogue(s) • First point source catalogue will be opened to public in next spring