TY - JOUR
T1 - MegaZ-LRG
T2 - A photometric redshift catalogue of one million SDSS luminous red galaxies
AU - Collister, Adrian
AU - Lahav, Ofer
AU - Blake, Chris
AU - Cannon, Russell
AU - Croom, Scott
AU - Drinkwater, Michael
AU - Edge, Alastair
AU - Eisenstein, Daniel
AU - Loveday, Jon
AU - Nichol, Robert
AU - Pimbblet, Kevin
AU - De Propris, Roberto
AU - Roseboom, Isaac
AU - Ross, Nic
AU - Schneider, Donald P.
AU - Shanks, Tom
AU - Wake, David
PY - 2007/2
Y1 - 2007/2
N2 - We describe the construction of MegaZ-LRG, a photometric redshift catalogue of over one million luminous red galaxies (LRGs) in the redshift range 0.4 < z < 0.7 with limiting magnitude i < 20. The catalogue is selected from the imaging data of the Sloan Digital Sky Survey (SDSS) Data Release 4. The 2dF-SDSS LRG and Quasar (2SLAQ) spectroscopic redshift catalogue of 13 000 intermediate-redshift LRGs provides a photometric redshift training set, allowing use of ANNZ, a neural network-based photometric-redshift estimator. The rms photometric redshift accuracy obtained for an evaluation set selected from the 2SLAQ sample is σz. = 0.049 averaged over all galaxies, and σz = 0.040 for a brighter subsample (i < 19.0). The catalogue is expected to contain ∼5 per cent stellar contamination. The ANNZ code is used to compute a refined star/galaxy probability based on a range of photometric parameters; this allows the contamination fraction to be reduced to 2 per cent with negligible loss of genuine galaxies. The MegaZ-LRG catalogue is publicly available on the World Wide Web from http://www.2slaq.info.
AB - We describe the construction of MegaZ-LRG, a photometric redshift catalogue of over one million luminous red galaxies (LRGs) in the redshift range 0.4 < z < 0.7 with limiting magnitude i < 20. The catalogue is selected from the imaging data of the Sloan Digital Sky Survey (SDSS) Data Release 4. The 2dF-SDSS LRG and Quasar (2SLAQ) spectroscopic redshift catalogue of 13 000 intermediate-redshift LRGs provides a photometric redshift training set, allowing use of ANNZ, a neural network-based photometric-redshift estimator. The rms photometric redshift accuracy obtained for an evaluation set selected from the 2SLAQ sample is σz. = 0.049 averaged over all galaxies, and σz = 0.040 for a brighter subsample (i < 19.0). The catalogue is expected to contain ∼5 per cent stellar contamination. The ANNZ code is used to compute a refined star/galaxy probability based on a range of photometric parameters; this allows the contamination fraction to be reduced to 2 per cent with negligible loss of genuine galaxies. The MegaZ-LRG catalogue is publicly available on the World Wide Web from http://www.2slaq.info.
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U2 - 10.1111/j.1365-2966.2006.11305.x
DO - 10.1111/j.1365-2966.2006.11305.x
M3 - Review article
AN - SCOPUS:33846697283
SN - 0035-8711
VL - 375
SP - 68
EP - 76
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -