Mock Lightcones and Theory Friendly Catalogs for the CANDELS survey

The Cosmic Assembly Near-infrared Deep Extragalactic Survey (CANDELS) is a multi-wavelength deep sky survey anchored in a Multi-cycle Treasury program with the Hubble Space Telescope (HST; PI S. Faber & H. Ferguson). CANDELS took Near-IR images with the Wide Field Camera 3 (WFC3) in five fields that were already well studied at many different wavelengths: COSMOS, EGS, GOODS-N, GOODS-S, and the UDS. The CANDELS team and the community have compiled extensive ancillary observations, both imaging and spectroscopy, in these fields. Physical parameters such as redshifts, stellar masses, star formation rates, etc., have been estimated from the Spectral Energy Distributions (SED).

As part of the CANDELS program, the theory team created custom “mock CANDELS” catalogs. These were created by extracting the dark matter halos from a large cosmological simulation along the past lightcone corresponding to a field with the same geometry and sky location as one of the real CANDELS fields. These halos are then populated with galaxy properties using two different techniques: an empirical technique known as Sub-Halo Abundance Matching (using the UniverseMachine built by P. Behroozi & collaborators), and Semi-analytic Models of galaxy formation. Three sets of mock lightcone catalogs were produced, called UniverseMachine, Santa Cruz SAM (SC-SAM), and Lu-SAM.

In order to facilitate comparison between theoretical models and the CANDELS observations, we have created a set of curated “theory friendly” catalogs for the CANDELS observed quantities and physical properties derived from the observations.

Here we provide supplementary documentation for the mock catalogs and theory friendly catalogs, and access to the theory friendly catalogs and SC-SAM catalogs. The UniverseMachine CANDELS lightcones are available here

All catalogs may also be previewed, filtered, and downloaded from

For more information about the CANDELS survey, the theory friendly catalogs, and the theoretical mock catalogs, please see the following references:

• CANDELS survey design and execution: Grogin et al. (2011); Koekemoer et al. (2011)
• CANDELS theory friendly catalogs: Somerville et al. (2020)
• CANDELS mock catalogs: Lu et al. (2014); Somerville et al. (2020)

Supplementary information for SC-SAM and Lu-SAM mock catalogs

File download for SC-SAM catalogs

Supplementary information for theory friendly CANDELS observational catalogs

Effective area tables for CANDELS observed fields

Candels and SAM comparison chart
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