David E. Johnston

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Max Tegmark, Michael A. Strauss, Michael R. Blanton, Kevork Abazajian, Scott Dodelson, Havard Sandvik, Xiaomin Wang, David H. Weinberg, Idit Zehavi, Neta A. Bahcall, Fiona Hoyle, David Schlegel, Roman Scoccimarro, Michael S. Vogeley, Andreas Berlind, Tamás Budavari, Andrew Connolly, Daniel J. Eisenstein, Douglas Finkbeiner, Joshua A. Frieman, James E. Gunn,(More)
Max Tegmark, Daniel J. Eisenstein, Michael A. Strauss, David H. Weinberg, Michael R. Blanton, Joshua A. Frieman, Masataka Fukugita, James E. Gunn, Andrew J. S. Hamilton, Gillian R. Knapp, Robert C. Nichol, Jeremiah P. Ostriker, Nikhil Padmanabhan, Will J. Percival, David J. Schlegel, Donald P. Schneider, Roman Scoccimarro, Uroš Seljak, Hee-Jong Seo, Molly(More)
We measure the large-scale real-space power spectrum P (k) using a sample of 205,443 galaxies from the Sloan Digital Sky Survey, covering 2417 effective square degrees with mean redshift z ≈ 0.1. We employ a matrix-based method using pseudo-Karhunen-Loève eigenmodes, producing uncorrelated minimumvariance measurements in 22 k-bands of both the clustering(More)
This paper describes the Fifth Data Release (DR5) of the Sloan Digital Sky Survey (SDSS). DR5 includes all survey quality data taken through June 2005 and represents the completion of the SDSS-I project (whose successor, SDSSII will continue through mid-2008). It includes five-band photometric data for 217 million objects selected over 8000 deg, and(More)
The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which(More)
This paper describes the fourth data release of the Sloan Digital Sky Survey (SDSS), including all survey-quality data taken through June 2004. The data release includes five-band photometric data for 180 million objects selected over 6670 deg, and 673,280 spectra of galaxies, quasars, and stars selected from 4783 deg of that imaging data using the standard(More)
The Sloan Digital Sky Survey has validated and made publicly available its Second Data Release. This data release consists of 3324 square degrees of five-band (u g r i z) imaging data with photometry for over 88 million unique objects, 367,360 spectra of galaxies, quasars, stars and calibrating blank sky patches selected over 2627 degrees of 31 Enrico Fermi(More)
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 ΛCDM cosmology, we find σ8(Ωm/0.25) 0.41 = 0.832±0.033 after marginalization over all systematics. In common with previous studies, our error budget is dominated by(More)
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). We present non-parametric inversions of the 2D shear profiles to the mean 3D cluster density and mass profiles in bins of both optical richness and cluster i-band luminosity.(More)
We present a three-dimensional cosmic shear analysis of theHubble Space TelescopeCOSMOS survey, the largest ever optical imaging program performed in space.We have measured the shapes of galaxies for the telltale distortions caused by weak gravitational lensing and traced the growth of that signal as a function of redshift. Using both 2D and 3D analyses, we(More)