1. Development of a near-infrared wide-field integral field unit by ultra-precision diamond cutting
- Author
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Kushibiki, Kosuke, Ozaki, Shinobu, Takeda, Masahiro, Hosobata, Takuya, Yamagata, Yutaka, Morita, Shinya, Tsuzuki, Toshihiro, Nakagawa, Keiichi, Saiki, Takao, Ohtake, Yutaka, Mitsui, Kenji, Okita, Hirofumi, Kitagawa, Yutaro, Kono, Yukihiro, Motohara, Kentaro, Takahashi, Hidenori, Konishi, Masahiro, Kato, Natsuko, Koyama, Shuhei, and Chen, Nuo
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
Integral Field Spectroscopy (IFS) is an observational method to obtain spatially resolved spectra over a specific field of view (FoV) in a single exposure. In recent years, near-infrared IFS has gained importance in observing objects with strong dust attenuation or at high redshift. One limitation of existing near-infrared IFS instruments is their relatively small FoV, less than 100 arcsec$^2$, compared to optical instruments. Therefore, we have developed a near-infrared (0.9-2.5 $\mathrm{\mu}$m) image-slicer type integral field unit (IFU) with a larger FoV of 13.5 $\times$ 10.4 arcsec$^2$ by matching a slice width to a typical seeing size of 0.4 arcsec. The IFU has a compact optical design utilizing off-axis ellipsoidal mirrors to reduce aberrations. Complex optical elements were fabricated using an ultra-precision cutting machine to achieve RMS surface roughness of less than 10 nm and a P-V shape error of less than 300 nm. The ultra-precision machining can also simplify alignment procedures. The on-sky performance evaluation confirmed that the image quality and the throughput of the IFU were as designed. In conclusion, we have successfully developed a compact IFU utilizing an ultra-precision cutting technique, almost fulfilling the requirements., Comment: 24 pages, 18 figures, 7 tables. Accepted for publication in JATIS
- Published
- 2024
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