9 July 2008 Experiment of Wide Field Cryogenic Telescope II (WFCT II) at Sutherland, South African Astronomical Observatory
Author Affiliations +
Abstract
We have developed Wide Field Cryogenic Telescope II (WFCT II) which contains a whole telescope-optics together with a detector in a vacuum case for cooling to suppress thermal emission from a telescope. The telescope inside is a Ritchey-Chretien system with an aperture of 220 mm and a focal length of 1540 mm. Light from celestial objects enters the telescope through a window, hits primary and secondary mirrors, passes through a filter, and reaches a detector. Spiders, baffles, and radiation shields are cooled down to ~80 K or lower by a refrigerator. All the optics reach a low temperature by exchanging heat with the radiation shields. A 1024×1024 InSb infrared array detector covers a field of view of 1 square degree with resolution of 3".5/pixel. The detector is also cooled by the refrigerator and is regulated at 29 ± 0.1 K. WFCT II is mounted on a small equatorial mounting whose size is 1 m in height, 1 m in width, and 1.2 m in length along the N-S direction. The main targets are diffuse emissions radiated from hydrogen atoms, molecules, and carbonaceous materials in star formation regions and the Galactic Center. We have started to obtain scientific data at Sutherland, South African Astronomical Observatory since December 2007.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kentaro Haraguchi, Mikio Kurita, Shuji Sato, Weilai Gu, Tetsuya Nagata, Takahiro Nagayama, Takahiro Zenno, Daisuke Kato, "Experiment of Wide Field Cryogenic Telescope II (WFCT II) at Sutherland, South African Astronomical Observatory", Proc. SPIE 7014, Ground-based and Airborne Instrumentation for Astronomy II, 70146E (9 July 2008); doi: 10.1117/12.789020; https://doi.org/10.1117/12.789020
PROCEEDINGS
10 PAGES


SHARE
RELATED CONTENT


Back to Top