Related papers: Lucky Exposures: Diffraction limited astronomical …

Since its beginnings, diffraction-limited ground-based adaptive optics (AO) imaging has been limited to wavelengths in the near IR ({\lambda} > 1 micron) and longer. Visible AO ({\lambda} < 1 micron) has proven to be difficult because…

We report the cumulative results of an on-going near-infrared search for redshifted H-alpha emission from normal galaxies at z>2. An infrared search reduces the bias due to reddening. Using narrow-band imaging with the Near Infrared Camera…

Aims: We present a wide-field multi-color survey of a homogeneous sample of eleven clusters of galaxies for which we measure total masses and mass distributions from weak lensing. Methods: The eleven clusters in our sample are all X-ray…

A side-fed crossed Dragone telescope provides a wide field-of-view. This type of a telescope is commonly employed in the measurement of cosmic microwave background (CMB) polarization, which requires an image-space telecentric telescope with…

A modified version of the folded aplanatic Gregory telescope equipped with a spherical two-lens corrector is proposed for observations requiring a high signal-to-noise ratio. The basic telescope model has an aperture of 400 mm (f/3.0), its…

We utilize the CLASH (Cluster Lensing And Supernova survey with Hubble) observations of 25 clusters to search for extreme emission-line galaxies (EELGs). The selections are carried out in two central bands: F105W (Y105) and F125W (J125), as…

Recent monitoring programs of ultra cool field M and L dwarfs (low mass stars or brown dwarfs) have uncovered low amplitude photometric I-band variations which may be associated with an inhomogeneous distribution of photospheric…

Contemporary imaging air Cherenkov telescopes (IACT) for ground-based very high energy (VHE) gamma ray astronomy have prime focus optical design. Typically these telescopes have a 2-4 deg wide field of view (FoV). They use f/0.7-f/1.2…

We present an optically selected galaxy cluster catalog from ~ 2,700 square degrees of the Digitized Second Palomar Observatory Sky Survey (DPOSS), spanning the redshift range 0.1 < z < 0.5, providing an intermediate redshift supplement to…

We present integrated optical spectrophotometry for a sample of 417 nearby galaxies. Our observations consist of spatially integrated, S/N=10-100 spectroscopy between 3600 and 6900 Angstroms at ~8 Angstroms FWHM resolution. In addition, we…

As a contribution to the understanding of the dark energy concept, the Dark energy American French Team (DAFT, in French FADA) has started a large project to characterize statistically high redshift galaxy clusters, infer cosmological…

Earlier work has raised the potential importance of nebular emission in the derivation of the physical characteristics of high redshift Lyman break galaxies. Within certain redshift ranges, and especially at z ~ 6-7, such lines may be…

Light diffraction through a subwavelength aperture located at the apex of a metallic screen with conical geometry is investigated theoretically. A method based on a multipole field expansion is developed to solve Maxwell's equations…

{}From deep optical images of three clusters selected by virtue of their X-ray luminosity and/or optical richness (1455+22; $z=0.26$, 0016+16; $z=0.55$ and 1603+43; $z=0.89$), we construct statistically-complete samples of faint field…

Large ground-based telescopes equipped with adaptive optics (AO) systems have ushered in a new era of high-resolution infrared photometry and astrometry. Relative astrometric accuracies of <0.2 mas have already been demonstrated from…

General arguments for optimized coronagraphy in the search for planets are presented. First, off-axis telescopes provide the best telescopic platforms for use with coronagraphy, and telescope fabrication technology now allows the…

We have analysed ~24 square degrees of R_C-band imaging data from the Red-Sequence Cluster Survey (RCS), and measured the excess correlations between galaxy ellipticities on scales ranging from 1 to 30 arcminutes. We have used data from two…

We present a new sample of distant ultraluminous infrared galaxies. The sample was selected from a positional cross--correlation of the IRAS Faint Source Catalog with the FIRST database. Objects from this set were selected for spectroscopy…

We present optical and near-infrared photometry of 45 clusters of galaxies at 0.1 < z < 1.3. Galaxy catalogs in each cluster were defined at the longest wavelenth available, generally the K-band, down to approximately two magnitudes below…

Hubble Space Telescope images of high-redshift galaxies selected via color and photometric redshifts are used to examine the size and axial-ratio distribution of galaxies as a function of redshift at lookback times t > 8 Gyr. These…