Dark Energy Camera (DECam)

DECam is a high-performance, wide-field CCD imager mounted at the prime focus of the Blanco 4-m telescope at CTIO.   DECam imager contains 62 science CCDs with 520 megapixels and images 3 square degrees (2.2 degree wide field) at 0.27 arcsecond/pixel resolution.

DECam was built to carry out the Dark Energy Survey (DES) Project by the DES Collaboration, which is a Fermilab-led  international collaboration of over 120 scientists from 15 institutions and consortia in the USA, UK, Spain, Brazil and Germany.   DECam is an NOAO facility instrument, available to all users. The DES Collaboration, in exchange for the instrument and a community pipeline will receive 525 nights over 5 years to carry out the Dark Energy Survey. The project is funded by the DOE and NSF, the funding agencies of the UK, Spain, Brazil, and Germany, and contributions from the Collaboration institutions.

DATA:

  • NEW!  NOAO Data Handbook, DECam Chapter : The DECam Chapter of the NOAO Data Handbook contains information not only about the instrument and observing system, but also covers the data format and the processing done by the DECam Community Pipeline and the resulting data products.   N.B.   THIS IS A WORK IN PROGRESS!
  • All DES science verification data (December 2012-February 2013) raw images are available from the NOAO Science Archive (NSA).  This data has zero proprietary time.
  • A Community Pipeline operated by NOAO processes raw community-time DECam images and calibration frames into single and stacked frames with astrometric and rough photometric solutions.  All data are served from the NOAO Science Archive.
  • All DES raw images will be available from the NSA, respecting the 12-month proprietary period.  The first survey data will start becoming available on August 31 2014.
  • We will also serve single-images (i.e. not stacks) as reduced by the DES pipeline, respecting the 12 month proprietary time.  DES will only process and release, those images judged to be of survey quality.  Non-survey quality images may still be scientifically useful for some purposes. NOAO is evaluating whether to process and make available such non survey-quality images using the Community Pipeline, on request.  N.B. This policy is provisional, and may change 
  • DES will issue catalogs and stacks approximately mid-way through the survey  (~2016) and after completion of the survey (~2018-2019).

OBSERVING HELP:

  • Exposure Time Calculator v4 (Excel spreadsheet, by Darren DePoy and Alistair Walker). This ETC includes as-built optics transmissions, filter transmissions, CCD QE as a function of wavelength, and sky brightness at various lunar phases.  It should give reasonable estimates for stellar photometry with DECam.  BETA: v5 of the Exposure Time Calculator (Excel spreadsheet) is available.  This version provides sky brightness interpolation, but currently ONLY works in Excel (not compatible with other spreadsheet packages).

USEFUL LINKS:

IMPORTANT!


News:

  • 2014 March 17.   A VR filter, covering 500-760 nm so approximately twice the bandpass of the SDSS filters, has been successfully installed.   Images are still being evaluated, but looks good!   Exposure failures due to the shutter aborting are a thing of the past, with the replacement of a drive motor.   And, the sgutter and filter assembly interior axial surfaces have been painted with anti-reflection paint, and image contamination by bright stars just outside the FOV are greatly (factor 100?) attenuated.
  • 2013 December 17:  The Blanco dome encoder system has been replaced.  The new tape and reader provide accurate readings of the dome position (to better than one degree) and misalignments of telescope and dome should now be a thing of the past.
  • 2013 November 30:  CCD S30 is not working. Unlike the failure of N30 a year ago that was associated with over-illumination, S30 is exhibiting problems with one of its bias voltages.  It is not 100% sure whether the fault is with the CCD or associated electronics, tests are proceeding.  
  • 2013 October 28:  ETC updated to correct an incorrect value for the telescope collecting area, and also it now handles all lunar phases

About DECam

CTIO Contacts

Press

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CTIO DECam Support Pages (Internal Use Only)

CTIO DECam Support Staff for 2013A&B

CTIO DECam Support Staff for 2014A

DECam PropIDs & Special Cases (internal use only)