galaxies and increasingly also to determine their physical properties. Aims: To interpret the
observed UV spectra of distant galaxies in terms of the dominant radiation field and the
physical condition of the interstellar medium. Methods: We construct a large grid of
photoionization models and derive new spectral UV line diagnostics using equivalent widths
(EWs) of CIII] 1909, CIV1549 and the line ratios of CIII], CIV, and HeII1640 recombination …
Context. Ultraviolet (UV) emission-line spectra are used to spectroscopically confirm high-z
galaxies and increasingly also to determine their physical properties. Aims. We construct
photoionization models to interpret the observed UV spectra of distant galaxies in terms of
the dominant radiation field and the physical condition of the interstellar medium (ISM).
These models are applied to new spectroscopic observations from the VIMOS Ultra Deep
Survey (VUDS). Methods. We construct a large grid of photoionization models, which use …