EAZY, Easy and Accurate Zphot from Yale, determines photometric redshifts. The program is optimized for cases where spectroscopic redshifts are not available, or only available for a biased subset of the galaxies. The code combines features from various existing codes: it can fit linear combinations of templates, it includes optional flux- and redshift-based priors, and its user interface is modeled on the popular HYPERZ (ascl:1108.010) code. The default template set, as well as the default functional forms of the priors, are not based on (usually highly biased) spectroscopic samples, but on semi-analytical models. Furthermore, template mismatch is addressed by a novel rest-frame template error function. This function gives different wavelength regions different weights, and ensures that the formal redshift uncertainties are realistic. A redshift quality parameter, Q_z, provides a robust estimate of the reliability of the photometric redshift estimate.

The Unicorn pipeline produces data products from the 3D-HST grism survey of four CANDELS fields. It extracts interlaced 2D and 1D spectra for all objects in the Skelton et al. (2014) photometric catalogs. It then fits the 2D spectra and multi-band photometry to determine redshifts and emission line strengths. Unicorn is built on threedhst (ascl:2411.018) and has been superseded by grizli (ascl:1905.001).

threedhst reduces WFC3 grism exposures. It is essentially a wrapper around aXe (ascl:1109.016) and produces a catalog and other useful files; extracted 1D spectra are placed in a single file, and 2D spectra are in individual files. The code produces an HTML table with thumbnails of the direct images, 1D, and 2D spectra and supports the pipeline Unicorn (ascl:2411.019), which produces data products from the 3D-HST grism survey of four CANDELS fields. threedhst has been superceded by Grizli (ascl:1905.001).