SPICA infrared coronagraph and the study of exo-planets with it Barcelona, Spain, September 17th, 2009 K. Enya, T. Nakagawa, H. Kataza, T. Kotani (ISAS/JAXA), K. Haze (SOUKENDAI, ISAS/JAXA), S. Higuchi (Univ. of Tokyo, ISAS/JAXA), T. Miyata, S. Sako, T. Nakamura (IoA/Univ. Tokyo), M. Tamura, J. Nishikawa, T. Yamashita,N. Narita, H. Hayano (NAOJ), Y. Itoh (Kobe Univ.), T. Matsuo(JPL), M. Fukagawa, H. Shibai (Osaka Univ.), M. Honda (Kanagawa Univ.), N. Baba, N. Murakami(Hokkaido Univ.), L. Aｂe (Nice Univ), O. Guyon (NAOJ/SUBARU), M. Venet (Marseille Univ.), T. Yamamuro (Optcraft), P. Bierden (BMC), SPICA coroangarph team Contact: Keigo ENYA (email@example.com) SPICA mission • Please see presentation by Nakagawa. •An infrared space observatory - Aperture: 3.5m - Main wavelength: 5-200micron - Telescope temperature: 5K - Cooling: Mechanical cryo-coolers and radiation - Orbit: Sun-Eatrh L2 Halo - Launch year: 2018 • International mission including JAXA/ESA collaboration. • Pre-porject phase is ongoing. We consider SPICA is a unique opportunity for coronagraphic observation for exo-planet study. What can we do with coronagraph for SPICA? - Spectroscopy of atmosphere for outer exo-planets Detection From - More than 300 exo-planets by e.g., RV method - Direct imaging achieved!, while number of object is still small (Marois et al. 2008) Kalas et al. (2008) Spectroscopy of atmosphere by transit method - H2O, CH4, CO2 are found (Swain et al, Tinetti et al). - Hot topic, while the object is biased on hot-Jupiters. Next step - systematic characterization of the atmosphere To of many outer Jovian exo-planets to understand whole planetary system. - We are developing SPICA coronagraph instrument (SCI) having spectroscopy mode. An expected spectrum by SCI. (spectrum Is from Burows et al. 2Mj mass, 100Gyer old aroudn G2V star ) figure is by Kotani. Specification of SCI (1) Parameter Specification Core wavelength (λ) 3.5−27 micron Observation mode w/wo Coronagraph, Imaging/ •Aaa Coronagraphic mode Spectroscopy binary shaped pupil mask •Aaa Inner working angle (IWA) ~3.3×λ/D * Outer working angle (OWA) 16×λ/D Throughput ~20% Contrast 10-6 @PSF ( ~10-7 after subtraction) Detector 1k×1k Si:As, InSb array Estimation is T Matsuo based on Field of View ~1’ x 1’ Sivaramakrishnan et al.2009, Spectral resolution ~20 and ~200 Krist et al. 2007 Filter Band pass filters Disperser for spectroscopy transmissive devices (e.g. grism) in filter whele Active optics cryogenic DM and TTM (2) • Comparison to JWST coronagraph (1) Higher contrast (10-6 in a PSF. ) (2) Spectroscopy mode with continuous wavelength coverage Coronagraph method selection • Background - Broad band spectroscopy is needed - Telescope pointing is influenced by vibration made by mechanical cryo-coolers, compressors,… • We focused on binary shaped pupil mask - Achromatic work (except PSF size scaling with wavelength) - Very robust against telescope pointing error Pupil shape e.g., Jaquinot & Roizen dozierr(1964), Spergel (2001), Vanderbei et al. (2004) Kasdin et al (2005), PSF Binary mask for SPICA pupil Green et al.(2006) : 6 diffraction tail • Obstruction by the secondary mirror and support sturcture is serious problem. Binary mask for SPICA pupil Green et al.(2006) : 6 diffraction tail • Obstruction by the secondary mirror and support sturcture is serious problem. • Solution by 1-D coronagraph by multipled barcode mask Pupil shape design PSF (simulation) - IWA=3.3 lambda/D, Non-corona - Contrast ~6 grahic direction - Large discovery angle (only 2 diffraction tail) Discovery The principle of a barcode angle mask itself is presented Coronagrahic by Kasdin et al(2005). direction LOQO is used presented by Vanderbei(1995) Mask rotation Imaging 1 Then… Mask rotation Imaging 1 Total discovery angle is enlarged more w/o telescope roll Imaging 2 (Practically mask rotation will be realized by mask changer mechanism) Labo. experiment Demo. of principle with masks on substrate Enyta et al (2008) - with precise mask manufactured on BK7 substrate by electron beam drawing, visible laser, w/o AO → contrast of 6x10-8 achieved - Demo. of free standing (no substrate) mask for MIR coroangraph - experiment with visible laser, w/o AO was performed → 7x10-7 was confirmed. - demonstration in MIR is in preperation. Design of SCI Cryogenic active optics Cryogenic deformable mirror(DM) - MEMS DM: compact, large format (many channels) - Demo. with a prototype device succeeded. - Toughness demonstration against launch vibration is ongoing (numerical structure analysis, experimental vibration test) in the colaboration with BMC. Development of a cryogenic tip-tilt mirror is also ongoing. - to cancel the telescope pointing error produced Enya, Kataza, Bierden. (2008) by mechanical vibration SCI for monitor observation of planetary transit • Monitor observation of planetary transit - Powerful method to obtain atmospheric feature of exo-planets. - We are seriously considering to perform planetary transit observation • Why will we use SCI for the transit observation? - SCI has “non coronagraph mode” thanks to the mask changing machanism. - Simultaneous 1-27micron coverage of spectroscopy by two detector (a Si:As and a InSb. Wavelength region < 3.5um is not coronagraphic, but still have sensitivity) - The best pointing accuracy in the SPICA FPI(0.”03) thanks to TT. - Deforcusing by a deformable mirror: a potential solution for saturation problem - Internal calibrator designed for transit obsrevation. - Quick readout • Other MIR instruments of SPICA are also potentially useful. - MIRACLE: fide field camera (6’x 6’ fov) - MIRHES: high dispersion spectrometer (R=30000) Related presentation • Nakagawa et al. SPICA mission (talk) • Kotani et al. Our first result of WFC experiment (poster) - Contast has improved from 10-4 to better than 10-6 successfully. • Haze et al. Experiment with a vacuum chamber (poster) SPICA as a part of the pathway to Habitable planets Giant missions targeting habitable planets in future - Essentially important, no doubt - should be realized, probably in giant international collaboration (Both TPF-C and TPF-I may be OK as TPF with China and TPF with India) SPICA as a part of the pathway to Habitable planets Giant missions targeting habitable planets in future - Essentially important, no doubt - should be realized, probably in giant international collaboration (Both TPF-C and TPF-I may be OK as TPF with China and TPF with India) SPICA as a part of the pathway - Realistic goal : Jovian planets with 10-6 contrast - Scientific product : atlas of varisou exo-Jovian planet spectrum. - Technical product : light weight 3.5m telescope of SiC, high contrast optics, the first space telescope with fine WFC (except military satelite???), extensive study for stability,… - JAXA/ESA mission pre-project ongoing for near future! Both are important !!! Hopefully complementary. Summary We are developing a MIR coronagraph instrument (SCI) as one of FPI for SPICA. The primary target of SCI is the direct detection of exo-Jovian planets and spectroscopy of their atmospheric feature, including importantline, e.g., H2O, CH4, CO2, NH3. Unique capability of SCI. - High contrast (10-6 in a PSF) - Spectroscopy mode with continuous wavelength coverage (3.5-27 micron) Technical demonstrations are performed, or successfully ongoing. Planetary transit is quite important by-product. Summary We are developing a MIR coronagraph instrument (SCI) as one of FPI for SPICA. The primary target of SCI is the direct detection of exo-Jovian planets and spectroscopy of their We are deeply grateful to all of organizers atmospheric feature, including importantline, of H2O, CH4, CO2, NH3. e.g., the conference, contributers for our project, pioneers of this so interesting field, Unique capability of SCI. and everyone related to this work. - High contrast (10-6 in a PSF) - Spectroscopy mode with continuous wavelength coverage (3.5-27 micron) Technical demonstrations are performed, or successfully ongoing. Planetary transit is quite important by-product.
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