Related papers: Spitzer Massive Lensing Cluster Survey
We have analysed a sample of 574 Spitzer 4.5 micron-selected galaxies with [4.5]<23 and Ks_auto>24 (AB) over the UltraVISTA ultra-deep COSMOS field. Our aim is to investigate whether these mid-IR bright, near-IR faint sources contribute…
Gravitational lensing is brightening of background objects due to deflection of light by foreground sources. Rich clusters of galaxies are very effective lenses because they are centrally concentrated. Such natural Gravitational Telescopes…
Gravitational microlensing is a robust tool to detect and directly measure the abundance and mass of any kind of compact objects, either in our galaxy or in the extragalatic domain. On basis to generic, broadly applicable arguments, it is…
We present the results of a weak lensing survey of six high-redshift (z > 0.5), X-ray selected clusters of galaxies. We have obtained ultra-deep R-band images of each cluster with the Keck Telescope, and have measured a weak lensing signal…
We describe a project to study a sample of X-ray luminous clusters of galaxies at redshift z~0.2 at several scales (with HST/WFPC2 and CFHT/CFH12k) and wavebands (optical and X-ray). The main aims of the project are (i) to determine the…
We present results from a systematic search for strong gravitational lenses in the GOODS ACS data. The search technique involves creating a sample of likely lensing galaxies, which we define as massive early-type galaxies in a redshift…
Discovery of strongly-lensed gravitational wave (GW) sources will unveil binary compact objects at higher redshifts and lower intrinsic luminosities than is possible without lensing. Such systems will yield unprecedented constraints on the…
We present a new method for measuring the projected mass distributions of galaxy clusters. The gravitational amplification is measured by comparing the joint distribution in redshift and magnitude of galaxies behind the cluster with that of…
We propose a novel technique to refine the modelling of galaxy clusters mass distribution using gravitational lensing. The idea is to combine the strengths of both "parametric" and "non-parametric" methods to improve the quality of the fit.…
Weak gravitational lensing by galaxy clusters on faint higher redshift galaxies has been traditionally used to study the cluster mass distribution and as a tool to identify clusters as peaks in the shear maps. However, it becomes soon clear…
Weak lensing is one of the best available diagnostic tools to measure the total density profiles of distant clusters of galaxies. Unfortunately, it suffers from the well-known mass-sheet degeneracy, so that weak lensing analyses cannot lead…
Lensing in the context of rich clusters is normally quantified from small image distortions, yielding a relative mass distribution in the limit of weak lensing. Here we show the magnification effect of lensing can also be mapped over a…
(Abridged) This work explores the existence of high redshift massive galaxies unveiled with Spitzer+IRAC, but missed by conventional selection techniques based on optical and near-infrared observations. To this end, we use the…
The Planck Surveyor cosmic microwave background (CMB) imaging mission will make very sensitive maps of the whole sky at microwave, millimetre (mm) and sub-mm wavelengths. The steep source counts expected in the highest frequency Planck…
We stack Spitzer 24 micron images for ~7000 galaxies with 0.1<z<1 in the Chandra Deep Field South to probe the thermal dust emission in low-luminosity galaxies over this redshift range. Through stacking, we can detect mean 24 micron fluxes…
We present a search for gravitational arcs in a sample of X-ray luminous, medium redshift clusters of galaxies. The sample of clusters is called ARCRAIDER, is based on the ROSAT Bright Survey (RBS) and fulfills the following criteria: (a)…
We present an extensive spectroscopic follow-up campaign of 29 strong lensing (SL) selected galaxy clusters discovered primarily in the Second Red-Sequence Cluster Survey (RCS-2). Our spectroscopic analysis yields redshifts for 52…
Weak gravitational lensing of distant galaxies can probe the total projected mass distribution of foreground gravitational structures on all scales and has been used successfully to map the projected mass distribution of rich intermediate…
Massive foreground galaxy clusters magnify and distort the light of objects behind them, permitting a view into both the extremely distant and intrinsically faint galaxy populations. We present here the z ~ 6 - 8 candidate high-redshift…
We present a description of the observations and data reduction procedures for an extensive spectroscopic and multi-band photometric study of nine high redshift, optically-selected cluster candidates. The primary goal of the survey is to…