The Wide Field Survey Telescope (WFST) is a dedicated time-domain multi-band
(u, g, r, i, and z) photometric survey facility under construction.
In this paper, we present a preliminary study that assesses the quality of
photometric redshifts based on WFST by utilizing mock observations derived with
the galaxy catalog in the COSMOS/UltraVISTA field. We apply the template
fitting technique to estimate photometric redshifts by using the ZEBRA
photometric-redshift code and adopting a modified set of adaptive templates. We
evaluate the bias (median relative offset between the output photometric
redshifts and input redshifts), normalized median absolute deviation
(ΟNMADβ) and outlier fraction (foutlierβ) of photometric
redshifts in two typical WFST observational cases, the single 30-second
exposure observations (hereafter shallow mode) and co-added 50-minute exposure
observations (hereafter deep mode). We find bias\la0.006, \sigma_{\rm
NMAD}\la0.03, and f_{\rm outlier}\la5\% in the shallow mode and biasβ0.005, ΟNMADββ0.06, and foutlierββ17%--27% in the deep mode, respectively, under various lunar phases.
Combining the WFST mock observational data with that from the upcoming CSST and
Euclid surveys, we demonstrate that the zphotβ results can be
significantly improved, with foutlierββ1% and ΟNMADββ0.02.Comment: 20 pages, 13 figures. Accepted for publication in Research in
Astronomy and Astrophysics (RAA