Related papers: Flashlights: An Off-Caustic Lensed Star at Redshif…
We discuss the statistical properties of faint background galaxies detected in a deep Hubble Space Telescope ultraviolet (F336W) Wide Field Planetary Camera 2 image of the lensing cluster Abell 370 (z=0.37). By combining modelled field…
We report the discovery of transients among star clusters in a distant galaxy that is gravitationally lensed by a foreground galaxy cluster, and explore whether these transients correspond to: (i) intrinsic variations associated with…
We present new observations of the cluster-lens Abell 370: a deep HST/WFPC2 F675W image and ESO 3.6m spectroscopy of faint galaxies. These observations shade new lights on the statistical properties of faint lensed galaxies. In particular,…
We present a study of a very peculiar object found in the field of the cluster-lens Abell 370. This object displays, in HST imaging, a spectacular morphology comparable to nearby ring-galaxies. From spectroscopic observations at the CFHT,…
Individual highly magnified stars have been recently discovered at lookback times of more than half the age of the Universe, in lensed galaxies that straddle the critical curves of massive galaxy clusters. Having confirmed their…
We report the discovery of a redshift z=6.56 galaxy lying behind the cluster Abell 370. The object HCM 6A was found in a narrowband imaging survey using a 118 Angstrom bandpass filter centered at 9152 Ang in the LRIS camera on the 10 m Keck…
Highly magnified stars at cosmological distances ($z \gtrsim 0.7$) become detectable thanks to microlensing by intracluster stars near the critical curves of galaxy clusters. Multi-epoch photometric campaigns targeting caustic crossing…
Strong gravitational magnifications enable to detect faint background sources, resolve their internal structures, and even identify individual stars in distant galaxies. Highly magnified individual stars allow various applications,…
We report the discovery of an unusual emission line galaxy at redshift z=1.68 found from near-IR imaging and spectroscopic observations with ISAAC/VLT of a faint gravitationally lensed R-band drop-out behind the lensing cluster Abell 1835.…
We report the discovery of an extremely magnified star at redshift $z=2.65$ in James Webb Space Telescope (JWST) NIRISS pre-imaging of the Abell 2744 galaxy-cluster field. The star's background host galaxy lies on a fold caustic of the…
Massive galaxy clusters at intermediate redshift can magnify the flux of distant background sources by several magnitudes and we exploit this effect to search for lensed distant supernovae that may otherwise be too faint to be detected. A…
We report the discovery of a transient source in the central regions of galaxy cluster Abell 267. The object, which we call "PALS1", was found in a survey aimed at identifying highly-magnified Lyman-break galaxies in the fields of…
We present observations of SCP 06F6, an unusual optical transient discovered during the Hubble Space Telescope Cluster Supernova Survey. The transient brightened over a period of ~100 days, reached a peak magnitude of ~21.0 in both i_775…
We present a strong lensing analysis of the galaxy cluster Abell 370 (z=0.375) based on the recent multicolor ACS images obtained as part of the Early Release Observation (ERO) that followed the Hubble Service Mission #4. Back in 1987, the…
We report the discovery of a strongly lensed arc system around a field elliptical galaxy in Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) images of a parallel field observed during NICMOS observations of the HST Ultra-Deep…
During our Herschel Lensing Survey (HLS) of massive galaxy clusters, we have discovered an exceptionally bright source behind the z=0.22 cluster Abell 773, which appears to be a strongly lensed submillimeter galaxy (SMG) at z=5.2429. This…
We present a new lens model for the $z=0.375$ galaxy cluster Abell 370 based on previously spectroscopically confirmed lensed galaxies and new lensed systems identified in JWST data, including recent data from the MAGNIF program. Based on…
We present a strong lensing analysis on the massive cluster Abell 370 (A370; z = 0.375), using a combination of deep multi-band Hubble Space Telescope (HST) imaging and Multi-Unit Spectroscopic Explorer (MUSE) spectroscopy. From only two…
We present deep spectroscopic measurements of 18 distant field galaxies identified as gravitationally-lensed arcs in a Hubble Space Telescope image of the cluster Abell 2218. Redshifts of these objects were predicted by Kneib et al. (1996)…
We report Keck LRIS observations of an arc-like background galaxy near the center of Abell 2152 (z=0.043), one of the three clusters comprising the Hercules supercluster. The background object has a redshift z=0.1423 and is situated 25…