Search Publications
A large population of `Lyman-break' galaxies in a protocluster at redshift z ~ 4.1
White, Richard L.; Franx, Marijn; Illingworth, Garth D. +35 more
The most massive galaxies and the richest clusters are believed to have emerged from regions with the largest enhancements of mass density relative to the surrounding space. Distant radio galaxies may pinpoint the locations of the ancestors of rich clusters, because they are massive systems associated with `overdensities' of galaxies that are brig…
Elemental abundances in the intracluster medium as observed with XMM-Newton
Kaastra, J. S.; Tamura, T.; Bleeker, J. A. M. +2 more
XMM-Newton observations of 19 galaxy clusters are used to measure the elemental abundances and their spatial distributions in the intracluster medium. The sample mainly consists of X-ray bright and relaxed clusters with a cD galaxy. Along with detailed Si, S and Fe radial abundance distributions within 300-700 kpc in radius, the O abundances are a…
Isolated electrostatic structures observed throughout the Cluster orbit: relationship to magnetic field strength
Balogh, A.; Santolík, O.; Chen, L. +4 more
Available from http://www.copernicus.org/site/EGU/annales/22/7/2515.htm?FrameEngine=false;
The Contribution of Primordial Binaries to the Blue Straggler Population in 47 Tucanae
Ferraro, Francesco R.; Sills, Alison; Beccari, Giacomo +5 more
Recent observations of the blue straggler population in 47 Tucanae give the first detailed characterization of their spatial distribution in the cluster over its entire volume. Relative to the light distribution, blue stragglers appear to be overabundant in the core and at large radii. The observed surface density profile shows a central peak, a z…
Lithium abundances of the local thin disc stars
Lambert, David L.; Reddy, Bacham E.
Lithium abundances are presented for a sample of 181 nearby F and G dwarfs with accurate Hipparcos parallaxes. The stars are on circular orbits about the Galactic centre and, hence, are identified as belonging to the thin disc. This sample is combined with two published surveys to provide a catalogue of lithium abundances, metallicities ([Fe/H]), …
Dust and Diffuse Interstellar Bands in the za = 0.524 Absorption System toward AO 0235+164
Cohen, Ross D.; Burbidge, E. M.; Lyons, R. W. +3 more
We present new Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) NUV-MAMA and STIS CCD observations of the BL Lac object AO 0235+164 and the intervening damped Lyα (DLA) line at za=0.524. The line profile gives N(HI)=(5+/-1)×1021 cm-2 and, combined with the H I 21 cm absorption data, leads to…
High-Redshift Extremely Red Objects in the Hubble Space Telescope Ultra Deep Field Revealed by the GOODS Infrared Array Camera Observations
Dickinson, Mark; Ferguson, Henry C.; Grogin, Norman A. +9 more
Using early data from the Infrared Array Camera (IRAC) on the Spitzer Space Telescope, taken for the Great Observatories Origins Deep Survey (GOODS), we identify and study objects that are well detected at 3.6 µm but are very faint (and in some cases, invisible) in the Hubble Ultra Deep Field (HUDF) ACS and NICMOS images and in very deep VLT…
High Energy Transient Explorer 2 Observations of the Extremely Soft X-Ray Flash XRF 020903
Sakamoto, T.; Yamauchi, M.; Cline, T. +36 more
We report High Energy Transient Explorer 2 (HETE-2) Wide Field X-Ray Monitor/French Gamma Telescope observations of the X-ray flash XRF 020903. This event was extremely soft: the ratio log(SX/Sγ)=0.7, where SX and Sγ are the fluences in the 2-30 and 30-400 keV energy bands, is the most extreme value obse…
A Study of the Reionization History of Intergalactic Helium with FUSE and the Very Large Telescope
Kruk, J. W.; Shull, J. M.; Zheng, W. +8 more
We obtained high-resolution Far Ultraviolet Spectroscopic Explorer (FUSE; R~20,000) and Very Large Telescope (VLT; R~45,000) spectra of the quasar HE 2347-4342 in order to study the properties of the intergalactic medium between redshifts z=2.0 and 2.9. The high-quality optical spectrum allows us to identify approximately 850 H I absorption lines …
The Structure of the Local Interstellar Medium. III. Temperature and Turbulence
Redfield, Seth; Linsky, Jeffrey L.
We present 50 individual measurements of the gas temperature and turbulent velocity in the local interstellar medium (LISM) within 100 pc. By comparing the absorption line widths of many ions with different atomic masses, we can satisfactorily discriminate between the two dominant broadening mechanisms, thermal broadening and macroscopic nontherma…