311 datasets found

Within the framework of the COSMOGRAIL collaboration we present 7- and 8.5-year-long light curves and time-delay estimates for two gravitationally lensed quasars: SDSS...

We present four years of photometric observations of the doubly imaged quasar UM673, carried out in three filters (VRi) with the Danish 1.54m telescope at the La Silla...

We perform a detailed elemental abundance analysis of dwarf stars in the Galactic bulge, based on high-resolution spectra that were obtained while the stars were optically...

We provide single-epoch spectroscopic data for a sample of 13 lensed quasars. The sources have bolometric luminosities between 10^44.7-47.4^erg/s and black hole masses...

We present observational data of the double lensed quasar UM673 obtained with the 1.5-m telescope of the Maidanak Observatory and the 1.3-m SMARTS telescope at CTIO between 2006...

The optical variability database of the two images (A and B) of the gravitationally lensed quasar Q0957+561 is based on frames taken with the Liverpool Robotic Telescope in the...

We present accurate time delays for the quadruply imaged quasar HE 0435-1223. The delays were measured from 575 independent photometric points obtained in the R-band between...

We perform a detailed elemental abundance analysis of dwarf stars in the Galactic bulge, based on high-resolution spectra that were obtained while the stars were optically...

We present VRi photometric observations of the quadruply imaged quasar HE0435-1223, carried out with the Danish 1.54m telescope at the La Silla Observatory. Our aim was to...

The largest spectroscopically selected sample of strong gravitational lens systems presented and analyzed to date is that of the Sloan Lens ACS (SLACS) survey. For the 57...

We present a detailed elemental abundance analysis of OGLE-2008-BLG-209S, the source star of a new microlensing event towards the Bulge, for which we obtained a high-resolution...

Gravitationally lensed quasars can be used to map the mass distribution in lensing galaxies and to estimate the Hubble constant H0 by measuring the time delays between the...

Microlensing events have been observed regularly by surveys such as MACHO, OGLE and MOA. They offer an excellent way to probe the galactic structure, kinematics and stellar...

We have searched for microlensing variability in the light curves of five gravitationally lensed quasars with well-determined time delays: SBS 1520+530, FBQ 0951+2635, RX...

Spatially resolved CCD photometry of the Q2237+0305 gravitationally lensed quasar in V, R and I spectral bands from observations with the Maidanak 1.5-m telescope made in...

We present a catalog of secondary photometric standard stars in the neighborhood of 14 gravitationally lensed quasars. These stars were verified to be non variable using...

We present optical R-band light curves of the gravitationally lensed quasar SBS 1520+530 derived from data obtained at the Nordic Optical Telescope, from February 1999 to May...

A gravitational lens (GL)-search program, initiated in 1990 at the Nordic Optcal Telescope (NOT), has revealed several possible GL-candidates among a sample of 168 quasars...

We have derived the mass distribution of galaxy cluster Abell 1689 within 0.3h^-1^_70_Mpc of the cluster centre using its strong lensing (SL) effect on 32 background galaxies,...

We present the results of a survey for extremely red objects (EROs) undertaken in the fields of 10 massive galaxy cluster lenses at z~0.2, combining sensitive, high-resolution...