Search Publications
Hubble Space Telescope Observations of the Unusual Blue Compact Dwarf Galaxy Markarian 996
Thuan, Trinh X.; Izotov, Yuri I.; Lipovetsky, Valentin A.
We present Hubble Space Telescope Wide Field Planetary Camera 2 V and I images and Faint Object Spectrograph UV and optical spectrophotometry of the unusual blue compact dwarf galaxy Mrk 996. We found Mrk 996 to have a disk structure with a small scale length (0.4 kpc) and a two-arm spiral-like pattern confined to the inner 160 pc in radius. Nearl…
Unlensing Multiple Arcs in 0024+1654: Reconstruction of the Source Image
Tyson, J. Anthony; Turner, Edwin L.; Colley, Wesley N.
A unique reconstruction of the image of a high-redshift source galaxy responsible for multiple long arcs in the z = 0.4 cluster 0024+1654 is obtained by inverse lensing. Deep B- and I-band imaging with the Hubble Space Telescope enables high resolution of the arcs due to strong gravitational lensing of the background source. The gravitational lens…
Hubble Space Telescope Observations of Isolated Pulsars
Cordova, F. A.; Pavlov, G. G.; Stringfellow, G. S.
Using the COSTAR corrected Faint Object Camera on the Hubble Space Telescope, we have obtained deep ultraviolet and optical images of the fields containing three nearby radio pulsars spanning a range in age between ∼1 × 105 and 2 × 107 yr. Deep 7".4 × 7".4 images were obtained in the long-pass F130LP filter for the youngest, …
Main-Sequence Stars and the Star Formation History of the Outer Disk in the Large Magellanic Cloud
Krist, J.; Gallagher, J. S.; Stappers, B. +17 more
Using the Wide Field Planetary Camera 2 on the Hubble Space Telescope, we have obtained a deep color-magnitude diagram in V- and I-band equivalents for more than 2000 stars in a patch of the outer disk of the Large Magellanic Cloud (LMC). Aperture photometry is feasible from these data with good signal-to-noise ratio for stars with V <= 25, whi…
Galaxy Dark Matter: Galaxy-Galaxy Lensing in the Hubble Deep Field
Tyson, J. Anthony; dell'Antonio, Ian P.
In this Letter we present calibrated observations of the average mass of galaxies with 22 < I < 25 in the Hubble Deep Field. We measure the mean mass profile using the statistical gravitational lens distortion of faint blue background galaxies, based on 2221 foreground-background pairs. The observed weak lensing distortion is calibrated via …
Redshift Z approximately 1 Field Galaxies Observed with the Keck Telescope and the Hubble Space Telescope
Illingworth, Garth D.; Forbes, Duncan A.; Davis, Marc +10 more
We report results based on 35 new spectroscopic redshifts obtained with the Keck Telescope for field galaxies that also have photometry and morphology from survey images taken by the refurbished Hubble Space Telescope. A sample of 24 redshifts for galaxies fainter than I = 22 has a median redshift of z ~ 0.81. This result is inconsistent with the …
Goddard High-Resolution Spectrograph Observations of Procyon and HR 1099
Harper, Graham M.; Wood, Brian E.; Linsky, Jeffrey L. +1 more
Goddard High Resolution Spectrograph (GHRS) observations have revealed the presence of broad wings in the transition-region lines of AU Mic and Capella. It has been proposed that these wings are signatures of microflares in the transition regions of these stars and that the solar analog for this phenomenon might be the "transition region explosive…
Hubble Space Telescope Observations of Giant Arcs: High-Resolution Imaging of Distant Field Galaxies
Smail, Ian; Ellis, Richard S.; Kneib, Jean-Paul +4 more
We present Hubble Space Telescope (HST) imaging of eight spectroscopically confirmed giant arcs, pairs, and arclets. These objects have all been studied extensively from the ground, and we demonstrate the unique advantages of HST imaging in the study of such features by a critical comparison of our data with the previous observations. In particula…
First Detection of Platinum, Osmium, and Lead in a Metal-Poor Halo Star: HD 126238
Truran, James W.; Sneden, Christopher; Cowan, John J. +1 more
Using the Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST), we have detected the very heavy elements osmium, platinum, and lead in the metal-poor ([Fe/H] = -1.7) giant HD 126238, the first such detections of these elements in a Galactic halo star. Os and Pt are synthesized predominantly via rapid neutron captures (i.…
The Nuclear Disk of NGC 4261: Hubble Space Telescope Images and Ground-based Spectra
Ford, Holland; O'Connell, Robert W.; Ferrarese, Laura +2 more
We present Hubble Space Telescope Planetary Camera images and ground- based spectra of the nuclear region of NGC 4261 = 3C 270. The images reveal a sharply defined disk of dust whose projected major and minor axes are 1.79" and 0.77", respectively. The minor axis of the disk is nearly aligned with the radio axis of 3C 270. Our analysis shows that …