Search Publications
The Local Lyα Forest. IV. Space Telescope Imaging Spectrograph G140M Spectra and Results on the Distribution and Baryon Content of H I Absorbers
Shull, J. Michael; Stocke, John T.; Penton, Steven V.
We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) G140M spectra of 15 extragalactic targets, which we combine with GHRS/G160M data to examine the statistical properties of the low-z Lyα forest. With STIS, we detect 109 Lyα absorbers at significance level (SL) of >=4 σ over 0.002<z<0.069, with a total reds…
Hubble Space Telescope Observations of the White Dwarf Cooling Sequence of M4
Currie, Thayne; Rich, R. Michael; Gibson, Brad K. +7 more
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and theoretical, on the determination of the cluster age from the white dwarf cooling sequence. These include uncertainties in the distance to the cluster and the…
Physical Properties and Baryonic Content of Low-Redshift Intergalactic Lyα and O VI Absorption Line Systems: The PG 1116+215 Sight Line
Richter, Philipp; Tripp, Todd M.; Sembach, Kenneth R. +1 more
We present Hubble Space Telescope and Far Ultraviolet Spectroscopic Explorer observations of the intergalactic absorption toward QSO PG 1116+215 in the 900-3000 Å spectral region. We detect 25 Lyα absorbers along the sight line at rest-frame equivalent widths Wr>30 mÅ, yielding (dN/dz)Lyα=166+/-20 over an unblocked redshif…
GRAPES, Grism Spectroscopy of the Hubble Ultra Deep Field: Description and Data Reduction
Cimatti, A.; Daddi, E.; Panagia, N. +19 more
We present deep unbiased spectroscopy of the Hubble Ultra Deep Field (UDF) carried out using the slitless grism spectroscopy mode of the Advanced Camera for Surveys on the Hubble Space Telescope (HST). The Grism ACS Program for Extragalactic Science (GRAPES) achieves continuum detection as faint as zAB=27.2 using 40 orbits (9.2×104…
Photometric Redshift of X-Ray Sources in the Chandra Deep Field-South
Wolf, C.; Zheng, W.; Gilli, R. +10 more
Based on the photometry of 10 near-ultraviolet, optical, and near-infrared bands of the Chandra Deep Field-South, we estimate the photometric redshifts for 342 X-ray sources, which constitute ~99% of all the detected X-ray sources in the field. The models of spectral energy distribution are based on galaxies and a combination of power-law continuu…
The Nature of Faint 24 Micron Sources Seen in Spitzer Space Telescope Observations of ELAIS-N1
Elbaz, D.; Reach, W. T.; Chary, R. +7 more
The Spitzer Space Telescope has undertaken the deepest ever observations of the 24 µm sky in the European Large Area ISO Survey (ELAIS-N1) field, with the Multiband Imaging Photometer (MIPS) instrument, as part of GOODS Science Verification observations. We present completeness-corrected extragalactic source counts down to 24 µm flux d…
FUSE and STIS Observations of the Warm-hot Intergalactic Medium toward PG 1259+593
Richter, Philipp; Tripp, Todd M.; Sembach, Kenneth R. +1 more
We use Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph (STIS) spectra to study intergalactic absorption toward the quasar PG 1259+593 (zem=0.478), with a particular emphasis on the warm-hot intergalactic medium (WHIM). The combined FUSE and STIS spectrum of PG 1259+593 covers the full wavelength ra…
Cold Dust in Early-Type Galaxies. I. Observations
Brighenti, Fabrizio; Mathews, William G.; Bregman, Jesse D. +1 more
We describe far-infrared observations of early-type galaxies selected from the Infrared Space Observatory (ISO) archive. This rather inhomogeneous sample includes 39 giant elliptical galaxies and 14 S0 (or later) galaxies. These galaxies were observed with the array photometer PHOT on-board the ISO satellite using a variety of different observing …
Imaging of the Supernova Remnant Cassiopeia A with the Multiband Imaging Photometer for Spitzer (MIPS)
Egami, E.; Gehrz, R. D.; Krause, O. +20 more
We present new images of the supernova remnant (SNR) Cas A observed in the 24 and 70 µm bands of the Spitzer Space Telescope (Spitzer). The IR emission correlates well with the Si X-ray and optical [S II] emission but poorly with either the synchrotron-dominated radio structure or the continuum X-ray emission. The IR is therefore dominated b…
New Hipparcos-based Parallaxes for 424 Faint Stars
Gould, Andrew; Chanamé, Julio
We present a catalog of 424 common proper-motion companions to Hipparcos stars with good (>3 σ) parallaxes, thereby effectively providing new parallaxes for these companions. Compared with typical stars in the Hipparcos catalog, these stars are substantially dimmer. The catalog includes 20 white dwarfs and an additional 29 stars with MV