Proc. SPIE, pp. 107091T

Authors:

  • Yuto Kojima
  • Shigeyuki Sako
  • Ryou Ohsawa
  • Hidenori Takahashi
  • Mamoru Doi
  • Naoto Kobayashi
  • Tsutomu Aoki
  • Noriaki Arima
  • Ko Arimatsu
  • Makoto Ichiki
  • Shiro Ikeda
  • Kota Inooka
  • Yoshifusa Ita
  • Toshihiro Kasuga
  • Mitsuru Kokubo
  • Masahiro Konishi
  • Hiroyuki Maehara
  • Noriyuki Matsunaga
  • Kazuma Mitsuda
  • Takashi Miyata
  • Yuki Mori
  • Mikio Morii
  • Tomoki Morokuma
  • Kentaro Motohara
  • Yoshikazu Nakada
  • Shin-Ichiro Okumura
  • Yuki Sarugaku
  • Mikiya Sato
  • Toshikazu Shigeyama
  • Takao Soyano
  • Masaomi Tanaka
  • Ken’ichi Tarusawa
  • Nozomu Tominaga
  • Tomonori Totani
  • Seitaro Urakawa
  • Fumihiko Usui
  • Junichi Watanabe
  • Takuya Yamashita
  • Makoto Yoshikawa

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Abstract:

Tomo-e Gozen (Tomo-e) is a wide field optical camera for the Kiso $1.05$ m f$/3.1$ Schmidt telescope operated by the University of Tokyo. Tomo-e is equipped with 84 chips of front-illuminated CMOS image sensors with a microlens array. The field of view is about 20 square degrees and maximum frame rate is 2 fps. The CMOS sensor has 2160$\times$1200 pixels and a size of pixel is 19 microns, which is larger than those of other CMOS sensors. We have evaluated performances of the CMOS sensors installed in Tomo-e. The readout noise is 2.0 e$^-$ in 2 fps operations when an internal amplifier gain is set to 16. The dark current is 0.5 $e^-$/sec/pix at room temperature, 290K, which is lower than a typical sky background flux in Tomo-e observations, 50 e$^-$/sec/pix. The efficiency of the camera system peaks at approximately 0.7 in 500 nm.