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MOA-cam3: a wide-field mosaic CCD camera for a gravitational microlensing survey in New Zealand

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Abstract

We have developed a wide-field mosaic CCD camera, MOA-cam3, mounted at the prime focus of the Microlensing Observations in Astrophysics (MOA) 1.8-m telescope. The camera consists of ten E2V CCD4482 chips, each having 2k×4k pixels, and covers a 2.2 deg2 field of view with a single exposure. The optical system is well optimized to realize uniform image quality over this wide field. The chips are constantly cooled by a cryocooler at − 80° C, at which temperature dark current noise is negligible for a typical 1–3 min exposure. The CCD output charge is converted to a 16-bit digital signal by the GenIII system (Astronomical Research Cameras Inc.) and readout is within 25 s. Readout noise of 2–3 ADU (rms) is also negligible. We prepared a wide-band red filter for an effective microlensing survey and also Bessell V, I filters for standard astronomical studies. Microlensing studies have entered into a new era, which requires more statistics, and more rapid alerts to catch exotic light curves. Our new system is a powerful tool to realize both these requirements.

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Acknowledgements

This work is supported by a grant-in-aid for scientific research of the Japan Ministry of Education, Science, Sports and Culture. The authors are grateful to the staff of the National Astronomical Observatory Japan (Y. Kobayashi, S. Miyazaki, Y. Komiyama, H. Nakaya), to members of the Graduate School of Science (S. Sato, H. Shibai) and Instrument Development Group of the Technical Center of Nagoya University, to J. Hiraga in ISAS/JAXA, to staff of the Nishimura Co. Ltd., to H. Kondoh in AISIN, to A. Rakich in IRL and to B. Leach in ARC. Finally, the authors thank the anonymous reviewer for improving the manuscript and for general expert comments on the camera.

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Authors and Affiliations

  1. Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, 464-8601, Japan

    T. Sako, T. Sekiguchi, M. Sasaki, K. Okajima, F. Abe, Y. Itow, K. Kamiya, K. Masuda, Y. Matsubara, Y. Muraki & T. Sumi

  2. Institute for Information and Mathematical Sciences, Massey University, Auckland, New Zealand

    I. A. Bond

  3. Department of Physics and Astronomy, University of Canterbury, Christchurch, New Zealand

    J. B. Hearnshaw, P. M. Kilmartin & P. Tristram

  4. Jodrell Bank Observatory, The University of Manchester, Macclesfield, UK

    N. J. Rattenbury

  5. School of Chemical and Physical Sciences, Victoria University, Wellington, New Zealand

    D. J. Sullivan

  6. Advanced Space Technology Research Group, Institute of Aerospace Technology, Japan Aerospace Exploration Agency (JAXA), Tokyo, Japan

    T. Yanagisawa

  7. Orbital Debris Program Office, National Aeronautics and Space Administration (NASA), Washington, DC, USA

    T. Yanagisawa

  8. Department of Physics, University of Auckland, Auckland, New Zealand

    P. C. M. Yock

Authors
  1. T. Sako
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  2. T. Sekiguchi
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  3. M. Sasaki
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  4. K. Okajima
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  5. F. Abe
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  6. I. A. Bond
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  7. J. B. Hearnshaw
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  8. Y. Itow
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  9. K. Kamiya
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  10. P. M. Kilmartin
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  11. K. Masuda
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  12. Y. Matsubara
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  13. Y. Muraki
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  14. N. J. Rattenbury
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  15. D. J. Sullivan
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  16. T. Sumi
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  17. P. Tristram
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  18. T. Yanagisawa
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  19. P. C. M. Yock
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Corresponding author

Correspondence to T. Sako.

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Sako, T., Sekiguchi, T., Sasaki, M. et al. MOA-cam3: a wide-field mosaic CCD camera for a gravitational microlensing survey in New Zealand. Exp Astron 22, 51–66 (2008). https://doi.org/10.1007/s10686-007-9082-5

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  • DOI: https://doi.org/10.1007/s10686-007-9082-5

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