Benjamin P. Koester

Cross-correlation Weak Lensing of SDSS Galaxy Clusters. I. Measurements (2009)

Sheldon, Erin S., Johnston, David E., Scranton, Ryan, Koester, Benjamin P., McKay, Timothy A., Oyaizu, Hiroaki, ...

This is the first in a series of papers on the weak lensing effect caused by clusters of galaxies in Sloan Digital Sky Survey. The photometrically selected cluster sample, known as MaxBCG, includes...

Precision Measurements of the Cluster Red Sequence using an Error Corrected Gaussian Mixture Model (2009)

Hao, Jiangang, Koester, Benjamin P., Mckay, Timothy A., Rykoff, Eli S., Rozo, Eduardo, Evrard, August, ...

The red sequence is an important feature of galaxy clusters and plays a crucial role in optical cluster detection. Measurement of the slope and scatter of the red sequence are affected both by...

Galaxy Clusters in Formation: Determining the Age of the Red-Sequence in Optical and X-ray Clusters at z~1 with HST (2009)

Koester, Benjamin P., Gladders, Michael D., Gilbank, David G., Yee, H. K. C., Barbary, Kyle, Dawson, Kyle S., ...

Using deep two-band imaging from the Hubble Space Telescope, we measure the color-magnitude relations (CMR) of E/S0 galaxies in a set of 9 optically-selected clusters principally from the...

Cosmological Constraints from the SDSS maxBCG Cluster Catalog (2009)

Rozo, Eduardo, Wechsler, Risa H., Rykoff, Eli S., Annis, James T., Becker, Matthew R., Evrard, August E., ...

We use the abundance and weak lensing mass measurements of the SDSS maxBCG cluster catalog to simultaneously constrain cosmology and the richness--mass relation of the clusters. Assuming a flat...

Subaru Weak Lensing Measurements of Four Strong Lensing Clusters: Are Lensing Clusters Over-Concentrated? (2009)

Oguri, Masamune, Hennawi, Joseph F., Gladders, Michael D., Dahle, Haakon, Natarajan, Priyamvada, Dalal, Neal, ...

We derive radial mass profiles of four strong lensing selected clusters which show prominent giant arcs (Abell 1703, SDSS J1446+3032, SDSS J1531+3414, and SDSS J2111-0115), by combining detailed...

Constraining the Scatter in the Mass-Richness Relation of maxBCG Clusters With Weak Lensing and X-ray Data (2008)

Rozo, Eduardo, Rykoff, Eli S., Evrard, August, Becker, Matthew, McKay, Timothy, Wechsler, Risa H., ...

We measure the logarithmic scatter in mass at fixed richness for clusters in the maxBCG cluster catalog, an optically selected cluster sample drawn from SDSS imaging data. Our measurement is achieved...

An Improved Cluster Richness Estimator (2008)

Rozo, Eduardo, Rykoff, Eli S., Koester, Benjamin P., McKay, Timothy, Hao, Jiangang, Evrard, August, ...

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...

The Dust Content of Galaxy Clusters (2007)

Chelouche, Doron, Koester, Benjamin P., Bowen, David V.

We report on the detection of reddening toward z ~ 0.2 galaxy clusters. This is measured by correlating the Sloan Digital Sky Survey cluster and quasar catalogs and by comparing the photometric and...

The Galaxy Content of SDSS Clusters and Groups (2007)

Hansen, Sarah M., Sheldon, Erin S., Wechsler, Risa H., Koester, Benjamin P.

Imaging data from the Sloan Digital Sky Survey are used to characterize the population of galaxies in groups and clusters detected with the MaxBCG algorithm. We investigate the dependence of...

Cross-correlation Weak Lensing of SDSS galaxy Clusters II: Cluster Density Profiles and the Mass--Richness Relation (2007)

Johnston, David E., Sheldon, Erin S., Wechsler, Risa H., Rozo, Eduardo, Koester, Benjamin P., Frieman, Joshua A., ...

We interpret and model the statistical weak lensing measurements around 130,000 groups and clusters of galaxies in the Sloan Digital Sky Survey presented by Sheldon et al. 2007 (Paper I). We present...

Cosmological Constraints from SDSS maxBCG Cluster Abundances (2007)

Rozo, Eduardo, Wechsler, Risa H., Koester, Benjamin P., McKay, Timothy A., Evrard, August E., Johnston, David, ...

We perform a maximum likelihood analysis of the cluster abundance measured in the SDSS using the maxBCG cluster finding algorithm. Our analysis is aimed at constraining the power spectrum...

Optically-Selected Cluster Catalogs as a Precision Cosmology Tool (2007)

Rozo, Eduardo, Wechsler, Risa H., Koester, Benjamin P., Evrard, August E., McKay, Timothy A.

We introduce a framework for describing the halo selection function of optical cluster finders. We treat the problem as being separable into a term that describes the intrinsic galaxy content of a...

MaxBCG: A Red Sequence Galaxy Cluster Finder (2007)

Koester, Benjamin P., McKay, Timothy A., Annis, James, Wechsler, Risa H., Evrard, August E., Rozo, Eduardo, ...

Measurements of galaxy cluster abundances, clustering properties, and mass to- light ratios in current and future surveys can provide important cosmological constraints. Digital wide-field imaging...