This is a catalogue of photometric redshifts of galaxies in the
Stripe 82 obtained when morphology (galaxy size, ellipticity, Sérsic
index, and surface brightness) are included in training on galaxy
samples from the SDSS and the CFHT Stripe-82 Survey (CS82). Our
redshifts yield a 68th percentile error of 0.058(1 + z), and a outlier
fraction of 5.2 per cent.
This catalogue (with updates to the pervious version) contains 11358
(+2759) quasars (defined as brighter than absolute B magnitude -23),
3334 (+501) AGNs (defined as fainter than absolute B magnitude -23)
and 357 (+137) BL Lac objects from 1863 (+201) references.
This is a redacted version of the SDSS DR16 table prepared for VizieR
(V/154/sdss16). It is mainly here to facilitate local matches; for
original SDSS-related research, it is probably better to somewhere
else.
Over VizieR and SDSS, we are keeping most of the per-band values in
arrays to keep the column list manageable. Note that in ADQL, array
indexes are 1-based.
We are trying to orient our column names on SDSS but use underscores
instead of camel-casing (e.g. spec_obj_id instead of SpecObjID), since
mixed-case identifiers in SQL is asking for trouble.
To save space, we do not keep psf-based classifications, per-band
offsets, spectrum metadata, and USNO-related information in this
table. Let the operators know if you need any of that.
Stripe 82 Photometric Redshifts from SDSS Coadditions
Short Name:
s82 coadd cone
Date:
27 Dec 2024 08:31:03
Publisher:
The GAVO DC team
Description:
This survey gives photometric redshifts of objects within 275 deg²
(−50◦ < α < 60◦ and −1.◦25 < δ < +1.◦25) centered on the Celestial
Equator. Each piece of sky has ∼20 runs of repeated scanning by the
SDSS camera contributing and thus reaches ∼2 mag fainter than the SDSS
single pass data, i.e., to r ∼ 23.5 for galaxies.
The zCOSMOS redshift survey used 600h on the VIMOS spectrograph spread over
five observing seasons (2005-2009) to obtain spectra of about 20,000 galaxies
selected to have Iab < 22.5 across the full 1.7 deg2 of the COSMOS field.
This part, "zCOSMOS-bright", was designed to yield a high and fairly uniform
sampling rate (about 70%), with a high success rate in measuring redshifts
(approaching 100% at 0.5 < z < 0.8), and with sufficient
velocity accuracy
(about 100 km/s) to efficiently map the environments of galaxies down to the
scale of galaxy groups out to redshifts z ~ 1.
