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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 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. Additional information about the survey design is available on the CANDELS public web site

Acknowledgements: 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."

Also please reference both of the following two CANDELS survey papers, which provide further details about the survey:
  • CANDELS Survey: Grogin et al. 2011, ApJS 197, 35
  • CANDELS HST Data: Koekemoer et al. 2011, ApJS 197, 36
    • Latest news:

    Sep 20, 2013: CANDELS team releases V0.5 GOODS-N mosaics, up to Epoch 13

    The CANDELS team has released new mosaics for GOODS-N, consisting of the v0.5 release for Epochs 11, 12 and 13, out of the total 14-epoch GOODS-N dataset. In this release, epoch 11 constitutes the last of the remaining WFC3/IR F105W (Y-band) data, for the south-west portion of the Wide region, while epochs 12 and 13 consist of the Deep region observed in WFC3/IR F125W (J-band) and F160W (H-band). All three epochs also contain mosaics constructed from the parallel ACS data, all obtained with F814W, and in all cases the mosaics for both WFC3 and ACS include drizzled science images, inverse variance weight images, and exposure time maps. Please see the MAST/GOODS-N page for specific details about this epoch, which also contains links to the Interactive Display Page
    Data access: http://archive.stsci.edu/pub/hlsp/candels/goods-n/

    Other Recent News and Data Deliveries

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    Sep 17, 2013: CANDELS team releases V0.5 mosaics for the EGS-b field

    The CANDELS team has released new v0.5 mosaics for the EGS-b field, for both epoch 01 and epoch 02. Please see the MAST/CANDELS page for overall details and the MAST/CANDELS EGS page for specific details about this epoch, which also contains links to the Interactive Display Page.
    Data access: http://archive.stsci.edu/pub/hlsp/candels/egs/

    Aug 23, 2013: CANDELS team releases GOODS-S v1 photometric redshift training catalog (20,000 sources)

    The CANDELS team has released the GOODS-S v1 photometric redshift training catalog (Dahlen et al. 2013), which was used as a foundation to calibrate and "train" a total of 11 different photometric redshift codes that were compared to one another in this project, as a precursor to the full photometric redshift catalogs which are currently in preparation. This training catalog contains 20,000 sources selected from the WFC3/IR F160W full-depth mosaics of the GOODS-S field, observed in a total of 14 different passbands including HST/ACS, HST/WFC3, ground-based U-band and Ks, and all 4 bands of Spitzer/IRAC.

    The catalog, together with ancillary files, can be accessed at:
    http://archive.stsci.edu/pub/hlsp/candels/goods-s/catalogs/v1/photoz-training/

    Aug 09, 2013: CANDELS team releases full multi-band GOODS-S v1 catalog

    The CANDELS team has released the full v1 multi-band catalog of the GOODS-S field (Guo et al. 2013, ApJS 207, 24), based on the v1.0 CANDELS HST WFC3/IR F160W mosaic as the primary detection image. This catalog contains measurements for 34930 sources across wavebands including the GOODS+CANDELS+ERS+HUDF HST data (ACS F435W, F606W, F775W, F814W, F850LP and WFC3/IR F098M, F105W, F125W, F160W) as well as ground-based U-band and near-infrared imaging data from CTIO and VLT, and also Spitzer/IRAC.
    Data access: http://archive.stsci.edu/pub/hlsp/candels/goods-s/catalogs/v1/

    Jun 06, 2013: CANDELS team releases V0.5 GOODS-N mosaics, up to Epoch 10

    The CANDELS team has released new mosaics for GOODS-N, consisting of the v0.5 release for Epochs 8, 9 and 10. This release also provides exposure-time mosaics (*exp.fits), corresponding to the total integrated exposure time at each pixel (after having accounted for geometric distortion and the difference between mosaic pixel size and the detector pixels). Please see the MAST/GOODS-N page for specific details about this epoch, which also contains links to the Interactive Display Page
    Data access: http://archive.stsci.edu/pub/hlsp/candels/goods-n/

    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 measurements 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/

    Feb 22, 2013: CANDELS team releases v0.5 mosaics for GOODS-N epoch 07

    The CANDELS team has released the v0.5 mosaics for GOODS-N epoch 07. For more details, and for direct links to the data, please see the MAST/CANDELS GOODS-N page and the Interactive Display Page.

    Feb 07, 2013: CANDELS team releases V1.0 full-depth mosaics for COSMOS and GOODS-S

    The CANDELS team has released the V1.0 full-depth combined mosaics for COSMOS and GOODS-S, for all ACS and WFC3/IR data obtained by the team on these fields during Cycles 18-20, consisting of a total of 318 orbits.For more details, and for direct links to the data, please see the MAST/GOOD-S and MAST/COSMOS pages. Note that there is an interactive display for both the GOODS-S and COSMOS full mosaics.

    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 GN11, GN12, GN13 V0.5 9/20/2013 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 EGS-b 01,02 V0.5 09/17/2013 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
    GOODS-S Full v1 photo-z training catalog V1 08/23/2013 Data

    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/

    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.

    Additional Information

    Additional information is available on the CANDELS public web site: