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Related papers: Magnification Effects on Source Counts and Fluxes

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We interpret the large variety of redshift distributions of galaxies found by far-infrared and (sub-)millimeter deep surveys depending on their depth and wavelength using the B\'ethermin et al. (2012) phenomenological model of galaxy…

Astrophysics of Galaxies · Physics 2015-04-15 Matthieu Béthermin , Carlos De Breuck , Mark Sargent , Emanuele Daddi

Objects falling into an overdensity appear larger on its near side and smaller on its far side than other objects at the same redshift. This produces a dipolar pattern of magnification, primarily as a consequence of the Doppler effect. At…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-09 Camille Bonvin , Sambatra Andrianomena , David Bacon , Chris Clarkson , Roy Maartens , Teboho Moloi , Philip Bull

We investigate the gravitational lensing properties of lines of sight containing multiple cluster-scale halos, motivated by their ability to lens very high-redshift (z ~ 10) sources into detectability. We control for the total mass along…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Kenneth C. Wong , S. Mark Ammons , Charles R. Keeton , Ann I. Zabludoff

Microlensing of stars in strongly lensed galaxies can lead to temporary extreme magnification factors ($\mu\!>\!1000$), enabling their detection at high redshifts. Following the discovery of Icarus, several stars at cosmological distances…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-03 J. M. Palencia , J. M. Diego , B. J. Kavanagh , J. Martinez

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

Magnification bias, an observational effect of gravitational lensing in the weak regime, allows testing the cosmological model through angular correlations of sources at different redshifts. This effect has been observed in various…

Measurements of galaxy clustering in upcoming surveys such as those planned for the Euclid and Roman satellites, and the SKA Observatory, will be sensitive to distortions from lensing magnification and Doppler effects, beyond the standard…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-01 Roy Maartens , José Fonseca , Stefano Camera , Sheean Jolicoeur , Jan-Albert Viljoen , Chris Clarkson

We discuss several effects due to lensing of ultra high energy cosmic rays by the regular component of the galactic magnetic field. Large flux magnification around caustics can be a significant source of clustering in the arrival directions…

Astrophysics · Physics 2009-10-31 Diego Harari , Silvia Mollerach , Esteban Roulet

The identification and study of the first galaxies remains one of the most exciting topics in observational cosmology. The determination of the best possible observing strategies is a very important choice in order to build up a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 A. Maizy , J. Richard , M. A. De Leo , R. Pello , J. P. Kneib

It is well known that magnification bias, the modulation of galaxy or quasar source counts by gravitational lensing, can change the observed angular correlation function. We investigate magnification-induced changes to the shape of the…

Astrophysics · Physics 2008-12-18 Marilena LoVerde , Lam Hui , Enrique Gaztanaga

We use weak lensing shear measurements of six z>0.5 clusters of galaxies to derive the mean lensing redshift of the background galaxies used to measure the shear. Five of these clusters are compared to X-ray mass models and verify a mean…

Astrophysics · Physics 2009-11-10 D. Clowe , G. Luppino , N. Kaiser

We present a Bayesian framework to account for the magnification bias from both strong and weak gravitational lensing in estimates of high-redshift galaxy luminosity functions. We illustrate our method by estimating the $z\sim8$ UV…

The frequency and effects of multiple weak deflections in galaxy-galaxy lensing are investigated via Monte Carlo simulations. The lenses in the simulations are galaxies with known redshifts and known rest-frame blue luminosities. The…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Tereasa G. Brainerd

Galaxy-galaxy or galaxy-quasar lensing can provide important information on the mass distribution in the Universe. It consists of correlating the lensing signal (either shear or magnification) of a background galaxy/quasar sample with the…

Astrophysics · Physics 2009-05-05 R. Ziour , L. Hui

Gravitational lensing magnification modifies the observed spatial distribution of galaxies and can severely bias cosmological probes of large-scale structure if not accurately modelled. Standard approaches to modelling this magnification…

High redshift sources suffer from magnification or demagnification due to weak gravitational lensing by large scale structure. One consequence of this is that the distance-redshift relation, in wide use for cosmological tests, suffers…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Madhura Killedar , Paul D. Lasky , Geraint F. Lewis , Chris J. Fluke

In the presence of strong clustering, low-resolution surveys measure the summed contributions of groups of sources within the beam. The counts of bright intensity peaks are therefore shifted to higher flux levels compared to the counts of…

We study the effects of large-scale density fluctuations on strong gravitational lensing. Previous studies have focused mostly on weak lensing, since large-scale structure alone cannot produce multiple images. When a galaxy or cluster acts…

Astrophysics · Physics 2009-10-28 Rennan Bar-Kana

Direct observations of the first generation of luminous objects will likely become feasible over the next decade. The advent of the Next Generation Space Telescope (NGST) will allow imaging of numerous galaxies and mini-quasars at redshifts…

Astrophysics · Physics 2009-10-31 Rennan Barkana , Abraham Loeb

We present detailed calculations of the magnification distribution, including both weak and strong lensing, using very recent solutions of the Dyer-Roeder (1973) equation for light propagation in a inhomogeneous universe with a cosmological…