@article {27994, title = {MegaZ-LRG: a photometric redshift catalogue of one million SDSS luminous red galaxies}, journal = {Monthly Notices of the Royal Astronomical Society}, volume = {375}, year = {2007}, note = {n/a}, month = {February 1, 2007}, pages = {68-76}, abstract = {We describe the construction of MegaZ-LRG, a photometric redshiftcatalogue of over one million luminous red galaxies (LRGs) in theredshift range 0.4 \< z \< 0.7 with limiting magnitude i \< 20.The catalogue is selected from the imaging data of the Sloan Digital SkySurvey (SDSS) Data Release 4. The 2dF-SDSS LRG and Quasar (2SLAQ)spectroscopic redshift catalogue of 13000 intermediate-redshift LRGsprovides a photometric redshift training set, allowing use of ANNz, aneural network-based photometric-redshift estimator. The rms photometricredshift accuracy obtained for an evaluation set selected from the 2SLAQsample is σz = 0.049 averaged over all galaxies, andσz = 0.040 for a brighter subsample (i \< 19.0). Thecatalogue is expected to contain ~5 per cent stellar contamination. TheANNz code is used to compute a refined star/galaxy probability based ona range of photometric parameters; this allows the contaminationfraction to be reduced to 2 per cent with negligible loss of genuinegalaxies. The MegaZ-LRG catalogue is publicly available on the WorldWide Web from http://www.2slaq.info. }, url = {http://adsabs.harvard.edu/abs/2007MNRAS.375...68C}, author = {Collister, Adrian and Lahav, Ofer and Blake, Chris and Cannon, Russell and Croom, Scott and Drinkwater, Michael and Edge, Alastair and Eisenstein, Daniel and Loveday, Jon and Nichol, Robert and Pimbblet, Kevin and de Propris, Roberto and Roseboom, Isaac and Ross, Nic and Schneider, Donald P. and Shanks, Tom and Wake, David} }