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The CANDELS Multi-Cycle Treasury Program

The Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey, CANDELS (Grogin et al. 2011; Koekemoer et al. 2011), PI: S. Faber, Co-PI, H. Ferguson, is designed to document the first third of galactic evolution from z = 8 to 1.5 via deep imaging of more than 250,000 galaxies with WFC3/IR and ACS. It will also discover and characterize Type Ia SNe beyond z > 1.5 and establish their accuracy as standard candles for cosmology.

The survey targets five premier multi-wavelength sky regions; each has multi-wavelength data from Spitzer and other facilities plus extensive spectroscopy of the brighter galaxies. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to 109 solar masses out to redshift z ~ 8.

The program incorporates a "Wide" imaging survey to 2-orbit J+H depth over 720 sq. arcmin in the COSMOS, EGS, and UDS fields. It also includes a "Deep" imaging survey to ~12 orbit Y+J+H depth in the two GOODS fields, tiling ~60 sq. arcmin in each field. In combination with ultra-deep imaging from the Hubble Ultradeep Field program (GO 11563), the result is a three-tiered strategy that effciently samples both bright/rare and faint/common extragalactic objects.

By imaging each field region at least twice on two visits separated by ~60 days, the program also carries out an extensive search for high-redshift Type Ia SNe beyond z > 1.5. Iin addition, ultraviolet "daytime" UVIS exposures in GOODS-N exploit the unique CVZ opportunity in that field.

Latest news: May 06, 2013: CANDELS team releases full UDS v1 catalog

The CANDELS team has released the full v1 multi-band catalog of the UDS field (Galametz et al. 2013), based on the v1.0 HST WFC3/IR F160W mosaic as the primary detection image. This catalog contains meaurements for 35932 sources across 19 different wavebands, including the CANDELS HST data (ACS F606W, F814W and WFC3/IR F125W, F160W) as well as ground-based optical and near-infrared imaging from CFHT, Subaru, VLT and UKIRT, and Spitzer/IRAC.

Data access: http://archive.stsci.edu/pub/hlsp/candels/uds/catalogs/v1/

Released Products
  • Wide: Multidrizzled mosaics from each epoch in each filter; ultimately summed mosaics from both CANDELS epochs.
  • Deep: Multidrizzled mosaics from each epoch in each filter; ultimately summed mosaics including all CANDELS data from previous epochs.
  • UVIS: For the first epoch, single-drizzled tiles are available from the archive (one exposure per tile with no CR rejection); ultimately summed mosaics with CR rejection from multiple epochs.

Version Definition
  • v0.5 represents our best-effort calibration at that time, including bias-stripe and CTE corrections for ACS, but no corrections for WFC3/IR persistence.
  • v1.0 uses more mature instrument calibration files, improved astrometry where necessary, and persistence corrections for WFC3/IR where applicable.

Release Schedule
  • Wide (2-orbit depth, 2 visits): v0.5 three months after each epoch is obtained. v1.0 six months after the last epoch.
  • Deep (12-orbit depth, 13 visits, GOODS only): v0.5 three months after each epoch is obtained. v1.0 six months after the last epoch.

Acknowledgment

When using data from the CANDELS survey, please include the
following acknowledgement:

"This work is based on observations taken by the CANDELS Multi-Cycle Treasury Program with the NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555."

And please cite both of the following two CANDELS survey papers:

Additional Information

Additional information is available on the CANDELS public web site:

Data Download Options

The data are all on line and available through your browser or via ftp.
  • Via your browser:
    http://archive.stsci.edu/pub/hlsp/candels/ is the starting navigation point to all the CANDELS data.
  • FTP:
    ftp archive.stsci.edu and login as anonymous.
    cd /pub/hlsp/cosmos.
    From there you can navigate through the site to find the field and epoch of data of interest.
  • WGET
    You can download whole directories of data using wget commands like:
    wget -q -nH --cut-dirs=6 -r -l0 -c -N -np -R 'index*' -erobots=off http://archive.stsci.edu/pub/hlsp/candels/goods-s/gsd15/v0.5/

Image Mosaic Releases:

Field
Click for full description of available data		 Latest Release Latest Version1 Latest Delivery Date Data Directory
Click to go to the top level data directory
GOODS-N GN07 V0.5 2/19/2013 Data
GOODS-S Full combined mosaics of all epochs V1.0 2/7/2013 Data
UDS Full combined mosaics of epochs 01 & 02 V1.0 11/14/2011 Data
EGS EGS02 V0.5 11/14/2011 Data
COSMOS Full combined mosaics of epochs 01 & 02 V1.0 2/5/2013 Data

Catalog Releases:

Field
Click for full description of available data		 Latest Release Latest Version1 Latest Delivery Date Data Directory
Click to go to the top level data directory
UDS Full multiband v1 catalog V1 05/06/2013 Data