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Related papers: Shape, Color and Distance in Weak Gravitational Fl…

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The best gravitational lenses for detecting distant galaxies are those with the largest mass concentrations and the most advantageous configurations of that mass along the line of sight. Our new method for finding such gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Kenneth C. Wong , Ann I. Zabludoff , S. Mark Ammons , Charles R. Keeton , David W. Hogg , Anthony H. Gonzalez

Matter near a gravitational lens galaxy or projected along the line of sight (LOS) can affect strong lensing observables by more than contemporary measurement errors. We simulate lens fields with realistic three-dimensional mass…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Curtis McCully , Charles R. Keeton , Kenneth C. Wong , Ann I. Zabludoff

We are conducting a redshift survey of 177 flat-spectrum radio sources in 3 samples covering the 5GHz flux ranges 50-100, 100-200 and 200-250 mJy. So far, we have measured 124 redshifts with completenesses of 80%, 68% and 58% for the…

Astrophysics · Physics 2009-10-30 E. E. Falco , C. S. Kochanek , J. M. Munoz

In this paper, we assemble a well-defined sample of early-type gravitational lenses extracted from a large collection of 158 systems, and use the redshift distribution of galactic-scale lenses to test the standard cosmological model…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-20 Yu-Bo Ma , Shuo Cao , Jia Zhang , Shuaibo Geng , Yuting Liu , Tonghua Liu , Yu Pan

The gravitational lensing, as well as the velocity field and the cosmological light-cone warp, changes the observed correlation function of high-redshift objects. We present an analytical expression of 3D correlation function,…

Astrophysics · Physics 2009-10-31 Takahiko Matsubara

We present optical luminosity functions (LFs) of galaxies in the $^{0.1}g$, $^{0.1}r$, and $^{0.1}i$ bands, calculated using data in $\sim 40$ $deg^{2}$ sky area of LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in…

We introduce a new empirical function for modeling the spectral energy distributions of galaxies. We apply it to a sample of 590 galaxies in the region of the HDF with $z < 1.5$ using multi-color photometry with wide wavelength coverage…

Astrophysics · Physics 2009-11-06 Judith G. Cohen

Weak gravitational lensing can cause displacements, magnification, rotation and shearing of the images of distant galaxies. Most studies focus on the shear and magnification effects since they are more easily observed. In this paper we…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-04 Chihway Chang , Bhuvnesh Jain

It is generally thought that galaxies are embedded in dark matter halos extending well beyond their luminous matter. The existence of these galactic halos is mainly derived from the larger than expected velocities of stars and gas in the…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-28 Pierre Magain , Virginie Chantry

We obtained deep 8.5'x8.5' near-infrared images within four high-redshift survey fields, measured the Ks magnitudes of 300 optically selected galaxies with spectroscopic redshift 1.8<z<2.6, and compared the spatial clustering strength of…

Weak gravitational lensing measurements based on photometry are limited by shape noise, the variance in the unknown unlensed orientations of the source galaxies. If the source is a disk galaxy with a well-ordered velocity field, however,…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-08 David Wittman , Matthew Self

Absorption spectroscopy of gravitationally lensed quasars (GLQs) enables study of spatial variations in the interstellar and/or circumgalactic medium of foreground galaxies. We report observations of 4 GLQs, each with two images separated…

For 18 well-observed gravitationally lensed QSOs, we compare new non-parametric mass profiles for the lensing galaxies with stellar-population models derived from published HST photometry. The large volume of parameter space searched --…

Astrophysics · Physics 2009-11-10 Ignacio Ferreras , Prasenjit Saha , Liliya L. R. Williams

We demonstrate that gravitationally lensed quasars are easily recognized using image subtraction methods as time variable sources that are spatially extended. For Galactic latitudes |b|>20 deg, lensed quasars dominate the population of…

Astrophysics · Physics 2009-11-13 C. S. Kochanek , B. Mochejska , N. D. Morgan , K. Z. Stanek

Extensive analyses of statistical strong gravitational lensing are performed based on the final Cosmic Lens All Sky Survey (CLASS) well-defined statistical sample of flat spectrum radio sources and current estimates of galaxy luminosity…

Astrophysics · Physics 2009-11-07 Kyu-Hyun Chae

We use Keck laser guide star adaptive optics imaging and exploit the magnifying effects of strong gravitational lensing (the effective resolution is FWHM ~ 200 pc) to investigate the sub-kpc scale of an intermediate-redshift (z = 0.63)…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 M. W. Auger , T. Treu , B. J. Brewer , P. J. Marshall

For suitable gravitational lens systems with unknown lens redshifts, the redshifts and brightnesses (in different colours) of the lenses are predicted for a variety of cosmological models, for both elliptical and spiral galaxy lenses.…

Astrophysics · Physics 2007-05-23 Phillip Helbig

We study the evolution of elliptical galaxies at z >~ 1 on the basis of a sample of 247 Extremely Red Objects (EROs) with R-Ks >= 3.35 (AB) and Ks <= 22.1 (AB) constructed from BVRi'z'JHKs multicolor data of a 114 arcmin2 area in the…

The fraction of high-redshift sources which are multiply-imaged by intervening galaxies is strongly dependent on the cosmological constant, and so can be a useful probe of the cosmological model. However its power is limited by various…

Astrophysics · Physics 2009-10-31 Daniel J. Mortlock , Rachel L. Webster

We review in this paper the main results recently obtained on the identification and study of very high-z galaxies usinglensing clusters as natural gravitational telescopes. We present in detail our pilot survey with ISAAC/VLT, aimed at the…

Astrophysics · Physics 2009-11-10 R. Pello , D. Schaerer , J. Richard , J. - F. Le Borgne , J. - P. Kneib