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Related papers: Measuring Omega/b with weak lensing

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Redshift space distortion (RSD) is a powerful way of measuring the growth of structure and testing General Relativity, but it is limited by cosmic variance and the degeneracy between galaxy bias b and the growth rate factor f. The…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Yan-Chuan Cai , Gary Bernstein

We derive constraints on the matter density \Om and the amplitude of matter clustering \sig8 from measurements of large scale weak lensing (projected separation R=5-30\hmpc) by clusters in the Sloan Digital Sky Survey MaxBCG catalog. The…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-11 Ying Zu , David H. Weinberg , Eduardo Rozo , Erin S. Sheldon , Jeremy L. Tinker , Matthew R. Becker

We use current observations on the number statistics of gravitationally lensed optical arcs towards galaxy clusters to derive an upper limit on the cosmological mass density of the Universe. The gravitational lensing statistics due to…

Astrophysics · Physics 2009-10-31 Asantha R. Cooray

In addition to the intrinsic clustering of galaxies themselves, the spatial distribution of galaxies observed in surveys is modulated by the presence of weak lensing due to matter in the foreground. This effect, known as magnification bias,…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-09 Lukas Wenzl , Shi-Fan Chen , Rachel Bean

Gravitational lensing of an optical QSO by a spiral galaxy is often counteracted by dust obscuration, since the line-of-sight to the QSO passes close to the center of the galactic disk. The dust in the lens is likely to be correlated with…

Astrophysics · Physics 2009-10-30 Rosalba Perna , Abraham Loeb , Matthias Bartelmann

We were asked to debate the value of the cosmological mass-density parameter Omega. Is Omega_m=1 in accordance with the simplest model? Is Omega_m much smaller as indicated by some observations? There is conflicting evidence. We lay out the…

Astrophysics · Physics 2007-05-23 Avishai Dekel , David Burstein , Simon D. M. White

We report on the first measurement of the average mass and mass-to-light ratio of galaxy groups by analysing the weak lensing signal induced by these systems. The groups, which have velocity dispersions of 50-400 km/s, have been selected…

We use weak lensing data from the Hubble Space Telescope COSMOS survey to measure the second- and third-moments of the cosmic shear field, estimated from about 450,000 galaxies with average redshift <z> ~ 1.3. We measure two- and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Elisabetta Semboloni , Tim Schrabback , Ludovic van Waerbeke , Sanaz Vafaei , Jan Hartlap , Stefan Hilbert

The 2dF Galaxy Redshift Survey is the first to observe more than 100,000 redshifts, making possible precise measurements of many aspects of galaxy clustering. The spatial distribution of galaxies can be studied as a function of galaxy…

Astrophysics · Physics 2009-11-07 J. A. Peacock

Given a foreground galaxy-density field or shear field, its cross-correlation with the shear field from a background population of source galaxies scales with the source redshift in a way that is specific to lensing. Such a source-scaling…

Astrophysics · Physics 2008-11-26 Jun Zhang , Lam Hui , Albert Stebbins

Cosmic magnification is due to the weak gravitational lensing of sources in the distant Universe by foreground large-scale structure leading to coherent changes in the observed number density of the background sources. Depending on the…

Weak gravitational lensing by large scale structure affects the number counts of faint galaxies through the ``magnification bias'' and thus affects the measurement of the angular two-point correlation function $\w $. At faint magnitudes the…

Astrophysics · Physics 2007-05-23 Jens Verner Villumsen

Accurate galaxy scaling relations are essential for a successful model of galaxy formation and evolution as they provide direct information about the physical mechanisms of galaxy assembly over cosmic time. We present here a detailed…

Astrophysics of Galaxies · Physics 2020-03-19 Bogdan A. Pastrav

We investigate the relationship between the colors, luminosities, and environments of galaxies in the Sloan Digital Sky Survey spectroscopic sample, using environmental measurements on scales ranging from 0.2 to 6 Mpc/h. We find: (1) that…

Astrophysics · Physics 2009-11-10 Michael R. Blanton , Daniel J. Eisenstein , David W. Hogg , Idit Zehavi

We measure the correspondence between the distribution of galaxies and matter around troughs and peaks in the projected galaxy density, by comparing \texttt{redMaGiC} galaxies ($0.15<z<0.65$) to weak lensing mass maps from the Dark Energy…

In this paper we obtain constraints on the cosmological density parameters, \Omega_m and \Omega_b, by comparing the preliminary measurement of the QSO power spectrum from the two degree field QSO redshift survey with results from an…

Astrophysics · Physics 2009-11-07 Kazuhiro Yamamoto

Galaxy-scale strong gravitational lenses with measured stellar velocity dispersions allow a test of the weak-field metric on kiloparsec scales and a geometric measurement of the cosmological distance-redshift relation, provided that the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Josiah Schwab , Adam S. Bolton , Saul A. Rappaport

Lensing probabilities of quasars with image separations greater than \Delta\theta and flux density ratios less than q_{\mathrm{r}} are calculated by foreground dark matter halos in a flat, cosmological constant dominated (\LambdaCDM)…

Astrophysics · Physics 2009-11-07 Da-Ming Chen

We investigate the correlation of gravitational lensing of the cosmic microwave background (CMB) with several tracers of large-scale structure, including luminous red galaxies (LRGs), quasars, and radio sources. The lensing field is…

Astrophysics · Physics 2008-11-26 Christopher M. Hirata , Shirley Ho , Nikhil Padmanabhan , Uros Seljak , Neta Bahcall

We study whether the bias factors of galaxies can be unbiasedly recovered from their power spectra and bispectra. We use a set of numerical N-body simulations and construct large mock galaxy catalogs based upon the semi-analytical model of…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-17 Hong Guo , Y. P. Jing
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