Related papers: Weak lensing evidence for a filament between A222/…
Weak shear maps of the outer regions of clusters have been successfully used to map the distribution of mass at large radii from the cluster center. The typical smoothing lengths employed thus far preclude the systematic study of the…
We propose a method for recovering the two-dimensional gravitational potential of galaxy clusters which combines data from weak and strong gravitational lensing. A first estimate of the potential from weak lensing is improved at the…
Microlensing observations toward globular clusters could be very useful to probe their low mass star and brown dwarf content. Using the large set of microlensing events detected so far toward the Galactic centre we investigated whether for…
Weak gravitational lensing studies of galaxy clusters often assume a spherical cluster model to simplify the analysis, but some recent studies have suggested this simplifying assumption may result in large biases in estimated cluster masses…
The cluster of galaxies A1795 hosts a 46 kpc-long filament at its core, which is clearly visible in the light of H-alpha and X-ray emission. We present optical slit spectroscopy and deeper Chandra X-ray data of the filament. The optical…
Strong lensing is one of the most direct probes of the mass distribution in the inner regions of galaxy clusters. It can be used to constrain the density profiles and to measure the mass of the lenses. Moreover, the abundance of strong…
We report the weak lensing discovery, spectroscopic confirmation, and weak lensing tomography of a massive cluster of galaxies at $z=0.68$, demonstrating that shear selection of clusters works at redshifts high enough to be cosmologically…
Weak gravitational lensing is an important tool to estimate the masses of galaxy clusters, as it allows us to directly access their projected surface mass density along the line-of-sight (LOS) in a manner largely independent of their…
The 3C 220.3 system is a rare case of a foreground narrow-line radio galaxy ("galaxy A," $z_A = 0.6850$) lensing a background submillimeter galaxy ($z_{{\rm SMG1}} = 2.221$). New spectra from MMT/Binospec confirm that the companion galaxy…
Abell 3827 is a unique galaxy cluster with a dry merger in its core causing a highly-resolved multiple-image configuration of a blue spiral galaxy at $z_\mathrm{s}=1.24$. The surface brightness profiles of four merging galaxies around…
We map substructure in three strong lensing systems having particularly good image data: the galaxy lens MG J0414+053 and the clusters SDSS J1004+411 and ACO 1689. Our method is to first reconstruct the lens as a pixelated mass map and then…
We present results of weak lensing cluster counts obtained from 11 sq.deg SuprimeCam data. Although the area is much smaller than previous work dealing with weak lensing peak statistics, the number density of galaxies usable for weak…
We present results from a combined weak lensing and X-ray analysis of the merging cluster A1914 at a redshift of $z=0.1712$ based on $R_{\rm}$-band imaging data with Subaru/Suprime-Cam and archival Chandra X-ray data. Based on the…
In this review, I discuss the use of galaxy-galaxy weak lensing measurements to study the masses of dark matter halos in which galaxies reside. After summarizing how weak gravitational lensing measurements can be interpreted in terms of…
Using stellar dynamics and strong gravitational lensing as complementary probes, Sand et al. (2002, 2003) have recently claimed strong evidence for shallow dark matter density profiles in several lensing clusters, which may conflict with…
The galaxy cluster XLSSC~122 is a rare system at $z = 1.98$, hosting surprisingly evolved member galaxies when the Universe was only one-third of its present age. Leveraging deep JWST/NIRCam imaging, we perform a weak-lensing analysis and…
Weak gravitational lensing and the Sunyaev-Zel'dovich effect provide complementary information on the composition of clusters of galaxies. Preliminary results from cluster SZ observations with the Very Small Array are presented. A Bayesian…
We present details of the discovery of XLSSJ022303.0-043622, a z=1.2 cluster of galaxies. This cluster was identified from its X-ray properties and selected as a z>1 candidate from its optical/near-IR characteristics in the XMM Large-Scale…
We present measurements of the masses of 20 X-ray luminous clusters of galaxies at intermediate redshifts, determined from a weak lensing analysis of deep archival R-band data obtained using the Canada-France-Hawaii-Telescope. Compared to…
We present an integral field spectroscopy survey of rich clusters of galaxies aimed at studying their lensing properties. Thanks to knowledge of the spectroscopic caracteristics of more than three families of multiple images in a single…