Martin Eriksen - The PAU Survey: Early demonstration of photometric redshift performance
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Europe/Madrid
Seminar (IFAE)
Seminar
IFAE
,
Description
The PAU Survey (PAUS) is an innovative photometric survey with 40 narrow bands
at the William Herschel Telescope (WHT). The narrow bands are spaced at 100\AA\
intervals covering the range 4500\AA\ to 8500\AA\ and, in combination with
standard broad bands, enable excellent redshift precision. This talk discuss
the technique, galaxy templates and additional photometric calibration used to
determine early photometric redshifts from PAUS. Using \textsc{bcnz2}, a new
photometric redshift code developed for this purpose, we characterise the
photometric redshift performance using PAUS data on the COSMOS field.
Comparison to secure spectra from zCOSMOS DR3 shows that PAUS achieves
$\sigma_{68} /(1+z) = 0.0037$ to $i_{\mathrm{AB}} < 22.5$ when
selecting the best
50\% of the sources based on a photometric redshift quality cut. Furthermore, a
higher photo-z precision ($\sigma_{68}/(1+z) \sim 0.001$) is obtained for a
bright and high quality selection, which is driven by the identification of
emission lines. We conclude that PAUS meets its design goals, opening up a
hitherto uncharted regime of deep, wide, and dense galaxy survey with precise
redshifts that will provide unique insights into the formation, evolution and
clustering of galaxies, as well as their intrinsic alignments.