The CCDs of HSC are fully-depleted-type 2048x4096 CCDs manufactured by Hamamatsu Photonics KK (S10892-02). The following plot shows the quantum efficiency of a typical CCD.

There are 104 main science CCDs, which provide a 90 arcmin field of view in diameter, as well as 4 CCDs for auto guider, and 8 CCDs for auto focus. The CCDs are arranged on the focal plane with two different gaps of approximately 12 arcsec and 53 arcsec between neighboring CCDs. The following figure shows the CCD arrangement.

CCD location

  • The 'SDO-ID' is an abbreviation of serial data output-ID , which consists of "T_BEEID"-"T_SDOID". The "T_BEEID", "T_SDOID", and "DET-ID" are FITS header keywords.

  • The "FRAMEID"'s of SDO-ID=0_{00-57} are HSCA?????X00-HSCA?????X57, where X is even number (0,2,4,6,8). For SDO-ID=1_{00-57}, the "FRAMEID"'s are HSCA?????Y00-HSCA?????Y57, where Y is odd number (1,3,5,7,9).

    • For expample,
      HSCA00000400 - HSCA00000457 : SDO-ID= 0_00 - 0_57
      HSCA00000500 - HSCA00000557 : SDO-ID= 1_00 - 1_57

  • As the data of AG CCDs are not stored and archived, you will get 112 CCD data (104 Sicence + 8 Focusing CCD data) per one shot.

  • Some CCDs show anomaly in counts for a specific range of data, and these data are not available as an science image. The following table shows which channels are not useful, listed with the periods and FRAMEIDs of data that are affected by the anomaly.

    SDO-ID DET-ID channel Period (UT) FRAMEID
    1_47 9 1 2014/4/3- HSCA00183600-
    2 2014/6/30- HSCA00343600-
    3,4 Occasionally, not available after 2014/6/30
    1_53 0 3 2014/6/24- HSCA00226000-
    1_9 43 4 2016/4/1- HSCA06440000-
    0_20 33 3 2016/12/23- HSCA09224600-
    4 2016/11/22- HSCA08945600-

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