TY - JOUR
T1 - Improvement of the richness estimates of maxBCG clusters
AU - Rozo, Eduardo
AU - Rykoff, Eli S.
AU - Koester, Benjamin P.
AU - McKay, Timothy
AU - Hao, Jiangang
AU - Evrard, August
AU - Wechsler, Risa H.
AU - Hansen, Sarah
AU - Sheldon, Erin
AU - Johnston, David
AU - Becker, Matthew
AU - Annis, James
AU - Bleem, Lindsey
AU - Scranton, Ryan
PY - 2009
Y1 - 2009
N2 - Minimizing the scatter between cluster mass and accessible observables is an important goal for cluster cosmology. In this work, we introduce a new matched filter richness estimator, and test its performance using the maxBCG cluster catalog. Our new estimator significantly reduces the variance in the LX -richness relation, from to . Relative to the maxBCG richness estimate, it also removes the strong redshift dependence of the LX -richness scaling relations, and is significantly more robust to photometric and redshift errors. These improvements are largely due to the better treatment of galaxy color data. We also demonstrate the scatter in the LX -richness relation depends on the aperture used to estimate cluster richness, and introduce a novel approach for optimizing said aperture which can easily be generalized to other mass tracers.
AB - Minimizing the scatter between cluster mass and accessible observables is an important goal for cluster cosmology. In this work, we introduce a new matched filter richness estimator, and test its performance using the maxBCG cluster catalog. Our new estimator significantly reduces the variance in the LX -richness relation, from to . Relative to the maxBCG richness estimate, it also removes the strong redshift dependence of the LX -richness scaling relations, and is significantly more robust to photometric and redshift errors. These improvements are largely due to the better treatment of galaxy color data. We also demonstrate the scatter in the LX -richness relation depends on the aperture used to estimate cluster richness, and introduce a novel approach for optimizing said aperture which can easily be generalized to other mass tracers.
KW - Cosmology: observations
KW - Methods: data analysis
UR - http://www.scopus.com/inward/record.url?scp=70549106585&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70549106585&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/703/1/601
DO - 10.1088/0004-637X/703/1/601
M3 - Article
AN - SCOPUS:70549106585
VL - 703
SP - 601
EP - 613
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
ER -