Search Publications
Kinematics of the Interstellar Medium in NGC 1705: Implications for Distant Star-Forming Galaxies
Heckman, Timothy M.; Leitherer, Claus
We report the results of space-ultraviolet (UV) spectroscopy of the super star cluster `1' in the nearby dwarf starburst galaxy NGC 1705, using the Goddard High Resolution Spectrograph on the Hubble Space Telescope. The exceptionally high UV flux and surface brightness of NGC 1705-1 makes it ideal for studying how UV spectral diagnostics can be us…
Low-Mass Binaries in the Hyades: A Scarcity of Brown Dwarfs
Gizis, John E.; Reid, I. Neill
We have obtained HST Planetary Carnera observations of a total of 53 low-mass (M<0.3Msun) members of the Hyades cluster. Nine of these stars are resolved as binaries, with separations between 0.1 and 3.1 arcseconds, while a further three are probably equal-mass systems at smaller separations. Allowing for observational selection effe…
HST Observations and Models of the Gravitational Lens System MG 0414+0534
Falco, Emilio E.; Lehar, Joseph; Shapiro, Irwin I.
Quadruple gravitational lens systems offer the possibility of measuring time delays for image pairs, microlensing effects, and extinction in distant galaxies. Observations of these systems may be used to obtain estimates of H0 and to study the various mass components of lens galaxies at high redshifts. With the Hubble Space Telescope, w…
Calibration of the Surface Brightness Fluctuation Method for use with the Hubble Space Telescope.
Lauer, Tod R.; Ajhar, Edward A.; Dressler, Alan +4 more
This paper presents the calibration of the surface brightness fluctuation (SBF) technique for use with the Wide Field and Planetary Camera-2 (WFPC-2) on the Hubble Space Telescope (HST). The calibration has a color term and zeropoint significantly different from the Kron-Cousins I-band SBF technique developed for ground-based observations. It is a…
Hubble Space Telescope Imaging of the Globular Cluster System Around NGC 5846
Forbes, Duncan A.; Brodie, Jean P.; Huchra, John
Bimodal globular cluster metallicity distributions have now been seen in a handful of large ellipticals. Here we report the discovery of a bimodal distribution in the dominant group elliptical NGC 5846, using the Hubble Space Telescope's Wide Field and Planetary Camera 2 (WFPC2). The two peaks are located at V-I=0.96 and 1.17, which roughly corres…
Hot Interstellar Gas in the Irregular Galaxy NGC 4449
Chu, You-Hua; Bomans, Dominik J.; Hopp, Ulrich
NGC 4449 is an irregular galaxy with a moderately high star formation activity. The massive stars in NGC 4449 have given rise to many bright HII regions, superbubbles, supergiant shells, and ``chimney-like'' radial filaments. ROSAT X-ray observations of NGC4449 have revealed four point-like sources and a wide-spread diffuse emission. The spectral …
Herbig Haro Objects in the Orion Nebula.
Hartigan, Patrick; Axon, David J.; O'Dell, C. R. +4 more
We have used the Hubble Space Telescope to image two regions of the Orion Nebula in low and high ionization emission lines. There appear to be two main systems of Herbig Haro objects in the Orion nebula - a `North' System is centered slightly north of the BN and IRc2 sources, and a `South' System centered south of the Trapezium stars. The North Sy…
HST High-Resolution Images and Maps of Pluto
Stern, S. A.; Trafton, L. M.; Buie, M. W.
We have obtained Hubble Space Telescope (HST) images of Pluto at 410 and 278 nm which resolve numerous distinct albedo provinces on this planet. Our images were obtained using the Faint Object Camera (FOC) of the Hubble Space Telescope between 1994 June 20 and July 01. This dataset is the first longitudinally-complete, rotationally-resolved direct…
Damped Lyalpha Absorption Associated with an Early-Type Galaxy at Redshift z=0.16377.
Meyer, David M.; Chen, Hsiao-Wen; Savaglio, Sandra +8 more
We report new HST and ground-based observations of a damped Lyα absorption system toward the QSO 0850+4400. The redshift of the absorption system is ζ=0.l63770±0.000054 and the neutral hydrogen column density of the absorption system is log N=19.81±0.04 cm-2. The absorption system is by far the lowest redshift confirmed damped Lyα absor…
Deep HST V- and I-Band Observations of Two Globular Clusters in the Halo of M31.
Richer, Harvey B.; Fahlman, Gregory G.; Holland, Stephen
We present deep (V∼=27) V- and I-band stellar photometry of G302 and G312, two globular star clusters in the halo of M31. These data were obtained using the Hubble Space Telescope's Wide Field/Planetary Camera 2. We find iron abundances of [Fe/H]= -1.85±0.12 for G302 and [Fe/H]=-0.56±0.03 for G312, consistent with spectroscopic measurements. The c…