TY - JOUR
T1 - Ameliorating systematic uncertainties in the angular clustering of galaxies
T2 - A study using the SDSS-III
AU - Ross, Ashley J.
AU - Ho, Shirley
AU - Cuesta, Antonio J.
AU - Tojeiro, Rita
AU - Percival, Will J.
AU - Wake, David
AU - Masters, Karen L.
AU - Nichol, Robert C.
AU - Myers, Adam D.
AU - de Simoni, Fernando
AU - Seo, Hee Jong
AU - Hernández-Monteagudo, Carlos
AU - Crittenden, Robert
AU - Blanton, Michael
AU - Brinkmann, J.
AU - da Costa, Luiz A.N.
AU - Guo, Hong
AU - Kazin, Eyal
AU - Maia, Marcio A.G.
AU - Maraston, Claudia
AU - Padmanabhan, Nikhil
AU - Prada, Francisco
AU - Ramos, Beatriz
AU - Sanchez, Ariel
AU - Schlafly, Edward F.
AU - Schlegel, David J.
AU - Schneider, Donald P.
AU - Skibba, Ramin
AU - Thomas, Daniel
AU - Weaver, Benjamin A.
AU - White, Martin
AU - Zehavi, Idit
PY - 2011/10
Y1 - 2011/10
N2 - We investigate the effects of potential sources of systematic error on the angular and photometric redshift, zphot, distributions of a sample of redshift 0.4 < z < 0.7 massive galaxies whose selection matches that of the Baryon Oscillation Spectroscopic Survey (BOSS) constant-mass sample. Utilizing over 112778 BOSS spectra as a training sample, we produce a photometric redshift catalogue for the galaxies in the Sloan Digital Sky Survey eight data release imaging area that, after masking, covers nearly one quarter of the sky (9913deg2). We investigate fluctuations in the number density of objects in this sample as a function of Galactic extinction, seeing, stellar density, sky background, airmass, photometric offset and North/South Galactic hemisphere. We find that the presence of stars of comparable magnitudes to our galaxies (which are not traditionally masked) effectively removes area. Failing to correct for such stars can produce systematic errors on the measured angular autocorrelation function, w(θ), that are larger than its statistical uncertainty. We describe how one can effectively mask for the presence of the stars, without removing any galaxies from the sample, and minimize the systematic error. Additionally, we apply two separate methods that can be used to correct for the systematic errors imparted by any parameter that can be turned into a map on the sky. We find that failing to properly account for varying sky background introduces a systematic error on w(θ). We measure w(θ), in four zphot slices of width 0.05 between 0.45 < zphot < 0.65, and find that the measurements, after correcting for the systematic effects of stars and sky background, are generally consistent with a generic Λ cold dark matter model, at scales up to 60°. At scales greater than 3° and zphot > 0.5, the magnitude of the corrections we apply is greater than the statistical uncertainty in w(θ). The photometric redshift catalogue we produce will be made publicly available at.
AB - We investigate the effects of potential sources of systematic error on the angular and photometric redshift, zphot, distributions of a sample of redshift 0.4 < z < 0.7 massive galaxies whose selection matches that of the Baryon Oscillation Spectroscopic Survey (BOSS) constant-mass sample. Utilizing over 112778 BOSS spectra as a training sample, we produce a photometric redshift catalogue for the galaxies in the Sloan Digital Sky Survey eight data release imaging area that, after masking, covers nearly one quarter of the sky (9913deg2). We investigate fluctuations in the number density of objects in this sample as a function of Galactic extinction, seeing, stellar density, sky background, airmass, photometric offset and North/South Galactic hemisphere. We find that the presence of stars of comparable magnitudes to our galaxies (which are not traditionally masked) effectively removes area. Failing to correct for such stars can produce systematic errors on the measured angular autocorrelation function, w(θ), that are larger than its statistical uncertainty. We describe how one can effectively mask for the presence of the stars, without removing any galaxies from the sample, and minimize the systematic error. Additionally, we apply two separate methods that can be used to correct for the systematic errors imparted by any parameter that can be turned into a map on the sky. We find that failing to properly account for varying sky background introduces a systematic error on w(θ). We measure w(θ), in four zphot slices of width 0.05 between 0.45 < zphot < 0.65, and find that the measurements, after correcting for the systematic effects of stars and sky background, are generally consistent with a generic Λ cold dark matter model, at scales up to 60°. At scales greater than 3° and zphot > 0.5, the magnitude of the corrections we apply is greater than the statistical uncertainty in w(θ). The photometric redshift catalogue we produce will be made publicly available at.
KW - Large-scale structure of Universe
KW - Methods: statistical
UR - http://www.scopus.com/inward/record.url?scp=80053580019&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80053580019&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2966.2011.19351.x
DO - 10.1111/j.1365-2966.2011.19351.x
M3 - Article
AN - SCOPUS:80053580019
SN - 0035-8711
VL - 417
SP - 1350
EP - 1373
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -