Japan Geoscience Union Meeting 2024

Presentation information

[J] Oral

P (Space and Planetary Sciences ) » P-CG Complex & General

[P-CG22] Origin and evolution of materials in space

Mon. May 27, 2024 9:00 AM - 10:30 AM 102 (International Conference Hall, Makuhari Messe)

convener:Hideko Nomura(Division of Science, National Astronomical Observatory of Japan), Takafumi Ootsubo(University of Occupational and Environmental Health,Japan), Aki Takigawa(Department of Earth and Planetary Science, The University of Tokyo), Sota Arakawa(Japan Agency for Marine-Earth Science and Technology), Chairperson:Aki Takigawa(Department of Earth and Planetary Science, The University of Tokyo), Sota Arakawa(Japan Agency for Marine-Earth Science and Technology)


10:15 AM - 10:30 AM

[PCG22-06] Latest status of the University of Tokyo Atacama Observatory (TAO) and the mid-infrared instrument MIMIZUKU

★Invited Papers

*Takafumi Kamizuka1, Takashi Miyata1, Shigeyuki Sako1, Itsuki Sakon1, Yuki Hirao1, Kengo Tachibana1, Akira C. Naruse1, Senoo Riko1, Yuki Kojima1 (1.The University of Tokyo)

Keywords:TAO, MIMIZUKU, mid-infrared, astronomical observations, hydrous mineral, crystalline silicate

The University of Tokyo Atacama Observatory (TAO) is an observatory currently under construction in the Atacama Desert in northern Chile. The site is located at the summit of Cerro Chajnantor at an altitude of 5640 m, making it the highest ground-based astronomical observatory in the world. The combination of high altitude and the desert climate makes the site ideal for infrared observations because the content of infrared-absorbing water in the air is kept low. This condition allows for stable observations in the Q-band (20-um band) and even at wavelengths up to 38 microns. Such a capability is quite limited for ground-based observatories.
To fully exploit this unique capability, we are constructing a 6.5-m telescope and preparing an infrared instrument, MIMIZUKU, to be mounted on the Nasmyth focus of the telescope. MIMIZUKU will enable imaging and low-resolution (R=110-660) spectroscopic observations over a wide wavelength range from 1 to 38 microns and achieves high spatial resolutions from 0.5 to 1.3 arcsec by being combined with the large aperture telescope. In addition, MIMIZUKU is equipped with a unique opto-mechanical system called Field Stacker, which enables simultaneous observation of two sky areas separated by less than 25 arcmin. By using this mechanism to observe a pair of a science target and a reference star, and comparing the observed signals from each object, we can accurately correct for the time-varying atmospheric absorption and obtain precise photometric/spectroscopic data. This feature enables long-term monitoring and observations in wavelength ranges affected by the atmospheric absorption.
MIMIZUKU has three optical channels: NIR, MIR-S, and MIR-L, covering 1-5, 7-26, and 24-38 microns, respectively. The MIR-S channel achieved its first light in engineering observations at the Subaru telescope in 2018 and successfully confirmed its functionality, as reported in the JpGU meeting 2019. Subsequently, MIMIZUKU was returned to Japan to complete the development of the NIR and MIR-L channels. The functionality of the NIR channel has been successfully confirmed in laboratory tests so far, and the MIR-L channel is now under development. As for the observatory, the operation buildings are almost completed, and the installation of the telescope will be started soon.
The commencement of scientific operations is approaching. About one-third of the observation time will be open to Japanese researchers. The unique capabilities of MIMIZUKU are expected to be useful for the study of cosmic materials, including the investigation of hydrous minerals (2.7- and 10-micron features), crystalline silicates (features in 10- and 20-micron bands), and organic/icy materials (3-micron feature) on small solar-system bodies, and monitoring of the formation and destruction of dust grains around evolved objects (red giants/supernovae) and young stars (extreme debris disks). In this talk, the latest status of TAO/MIMIZUKU and its applications to the study of cosmic materials will be presented.