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HSC CCDs

The CCDs of HSC are fully-depleted-type 2048 × 4096 pixel CCDs manufactured by Hamamatsu Photonics KK (S10892-02). The following plots show the typical quantum efficiency (left) and format (right) of the CCDs.

CCD QE CCD format

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 focus monitoring. 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 arrangement

  • 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" of SDO-ID=0_{00–57} are HSCA?????X00 – HSCA?????X57, where X is an even number (X = 0, 2, 4, 6, 8).

  • The "FRAMEID" of SDO-ID=1_{00–57} are HSCA?????Y00 – HSCA?????Y57, where Y is an odd number (Y = 1, 3, 5, 7, 9).

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

  • As the data of auto guider CCDs are not stored and archived, you will get 112 CCD data (104 Science + 8 Focusing) as FITS files per one shot.

  • Several of the CCDs include an anomaly in counts for a specific range of data which is not available as science data. The following table shows the CCDs/channels that are not useful with the periods and FRAMEIDs of data that were affected by the anomaly.

SDO-ID DET-ID Channel Period (UT) Frame ID Details
0_43 094 2 2014/03/24– HSCA00020400– Link
1_47(1) 009 1
2
3,4		 2014/04/03–
2014/06/30–
2017/04/02–		 HSCA00183600–
HSCA00343600–
HSCA10897400–		 Link
1_53 000 3 2014/06/24– HSCA00226000– Link
1_09 043 4 2016/04/01– HSCA06440000– Link
0_20 033 3
4		 2016/12/23–
2016/11/22–		 HSCA09224600–
HSCA08945600–		 Link
1_34(2) 021 1–4 2025/04/26– HSCA35932200– Link

Notes:
  1.  Read-out for CCD 009 (1_47) has been disabled since February 2018.
  2.  Read-out for CCD 021 (1_34) has been disabled since July 2025.

  • You can see the details of HSC's CCD anomalies here.

  • The following images are bias, dark, and domeflat frames (overscan subtracted) obtained in July 2025.

Bias frame Dark frame Flat frame


Last update: July 21, 2025