Photometric redshifts for the CFHTLS T0004 Deep and Wide fields

Details Photometric redshifts for the CFHTLS T0004 Deep and Wide fields Photometric redshifts for the CFHTLS T0004 Deep and Wide fields

2008-11-20

arxiv.org/abs/0811.3326v1

Astronomy and Astrophysics

Astrophysics

18 pages, 17 figures

Scientific paper

We compute photometric redshifts based on the template-fitting method in the fourth public release of the Canada-France-Hawaii Telescope Legacy Survey. This unique multi-colour catalogue comprises u*,g',r',i',z' photometry in four deep fields of 1 deg2 each and 35 deg2 distributed over three Wide fields. Our photometric redshifts are calibrated with and compared to 16,983 high-quality spectroscopic redshifts from several surveys. We find a dispersion of 0.028 and an outlier rate of 3.5% in the Deep field at i'AB < 24 and a dispersion of 0.036 and an outlier rate of 2.8% in the Wide field at i'AB < 22.5. Beyond i'AB = 22.5 in the Wide field the number of outliers rises from 5% to 10% at i'AB<23 and i'AB<24 respectively. For the Wide sample, we find the systematic redshift bias keeps below 1% to i'AB < 22.5, whereas we find no significant bias in the Deep field. We investigated the effect of tile-to-tile photometric variations and demonstrate that the accuracy of our photometric redshifts is reduced by at most 21%. We separate stars from galaxies using both the size and colour information, reducing the contamination by stars in our catalogues from 50% to 8% at i'AB < 22.5 in fields with the highest stellar density while keeping a complete galaxy sample. Our CFHTLS T0004 photometric redshifts are distributed to the community. Our release include 592,891 (i'AB < 22.5) and 244,701 (i'AB < 24) reliable galaxy photometric redshifts in the Wide and Deep fields, respectively.

Affiliated with

Also associated with

No associations

Rating

Photometric redshifts for the CFHTLS T0004 Deep and Wide fields does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Photometric redshifts for the CFHTLS T0004 Deep and Wide fields, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photometric redshifts for the CFHTLS T0004 Deep and Wide fields will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-668654