Search Publications
Weak Lensing Analysis of CL 1358+62 Using Hubble Space Telescope Observations
Franx, Marijn; Hoekstra, Henk; Kuijken, Konrad +1 more
We report on the detection of weak gravitational lensing of faint, distant background objects by Cl 1358+62, a rich cluster of galaxies at a redshift of z = 0.33. The observations consist of a large, multicolor mosaic of Hubble Space Telescope WFPC2 images. The number density of approximately 50 background objects arcmin-2 allows us to …
Morphological Studies of the Galaxy Populations in Distant ``Butcher-Oemler'' Clusters with the Hubble Space Telescope. II. AC 103, AC 118, and AC 114 at Z = 0.31
Smail, Ian; Ellis, Richard S.; Barger, Amy J. +2 more
We present new results of a program to study the detailed morphologies of galaxies in intermediate-redshift clusters and hence understand the physical origin of the enhanced star formation seen in these environments at earlier epochs. Deep, high-resolution imagery has been obtained of three rich clusters, AC 103, AC 118, and AC 114 at z = 0.31, th…
Hubble Space Telescope Imaging of the CFRS and LDSS Redshift Surveys. II. Structural Parameters and the Evolution of disk Galaxies to z ~ 11
Tresse, Laurence; Brinchmann, Jarle; Ellis, Richard +10 more
Several aspects of the evolution of star-forming galaxies are studied using measures of the two-dimensional surface brightness profiles extracted from Hubble Space Telescope images of a sample of 341 faint objects selected from the CFRS and LDSS redshift surveys. The galaxies have 0 < z < 1.3. The size function of disk scale lengths in disk-…
The Solar Corona Above Polar Coronal Holes as Seen by SUMER on SOHO
Wilhelm, Klaus; Marsch, Eckart; Dwivedi, Bhola N. +4 more
In order to address two of the principal scientific objectives of the Solar and Heliospheric Observatory (SOHO), studies of the heating mechanisms of the solar corona and the acceleration processes of the solar wind, we deduce electron temperatures, densities, and ion velocities in plumes and interplume regions of polar coronal holes using ultravi…
HST study of Lyman-alpha emission in star-forming galaxies: the effect of neutral gas flows
Mas-Hesse, J. M.; Terlevich, E.; Terlevich, R. +3 more
We present high dispersion HST GHRS UV spectroscopic observations of 8 H II galaxies covering a wide range of metallicities and physical properties. We have found Lyalpha \ emission in 4 galaxies with blueshifted absorption features, leading to P Cygni like profiles in 3 of them. In all these objects the O I and Si II absorption lines are also blu…
The Ultraviolet Spectroscopic Properties of Local Starbursts: Implications at High Redshift
Robert, Carmelle; Heckman, Timothy M.; Leitherer, Claus +2 more
We report the results of a systematic study of the vacuum ultraviolet (λ ~= 1150-2000 Å) spectra of a sample of 45 starburst and related galaxies observed with the IUE satellite. These span broad ranges in metallicity (from 0.02 to 3 times solar), bolometric luminosity (~107-4 × 1011 L⊙), and galaxy properties (e.g…
Luminosity Evolution of Early-Type Galaxies to z = 0.83: Constraints on Formation Epoch and Ω
van Dokkum, Pieter G.; Franx, Marijn; Kelson, Daniel D. +1 more
We present deep Keck telescope spectroscopy of eight galaxies in the luminous X-ray cluster MS 1054-03 at z=0.83. The data are combined with imaging observations from the Hubble Space Telescope (HST). The spectroscopic data are used to measure the internal kinematics of the galaxies, and the HST data are used to measure their structural parameters…
The Angular Clustering of Lyman-Break Galaxies at Redshift Z approximately 3
Giavalisco, Mauro; Dickinson, Mark E.; Pettini, Max +3 more
We have measured the angular correlation function w(θ) for a sample of 871 Lyman-break galaxies (LBGs) in five fields at redshift z ~ 3. Fitting the power law Aw θ-β to a weighted average of w(θ) from the five fields over the range 12" <~ θ <~ 330", we find Aw ~ 2 arcsecβ and β ~ 0.9. The slope is,…
Spiral Galaxies with WFPC2. II. The Nuclear Properties of 40 Objects
Carollo, C. M.; Stiavelli, M.; Mack, J.
We report the analysis of Hubble Space Telescope Wide Field Planetary Camera 2 F606W images of 40 spiral galaxies belonging to the sample introduced in Paper I, where 35 other targets were discussed. We describe the optical morphological properties of the new 40 galaxies, derive the surface brightness profiles for 25 of them, and present the resul…
An ultraviolet, optical and infrared study of Herbig Ae/Be stars
Waelkens, C.; Malfait, K.; Bogaert, E.
We have selected a list of 45 Herbig Ae/Be-type candidates on the base of their IRAS colors and their spectral types. We propose the presence of a broad infrared excess as a defining criterion for these stars, rather than the detection of circumstellar nebulosity. In this way, our selection also includes more evolved young stars, that are no longe…