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Hubble Space Telescope Images of Nearby Luminous Quasars. II. Results for Eight Quasars and Tests of the Detection Sensitivity
Schneider, Donald P.; Bahcall, John N.; Kirhakos, Sofia
Observations with the Wide-Field Camera of the Hubble Space Telescope (HST) are presented for eight intrinsically luminous quasars with redshifts between 0.16 and 0.29. These observations, when combined with a similar HST study of the quasar PKS 2349-014, show that luminous nearby quasars exist in a variety of environments.
Seven companion ga…The Geometry and Kinematics of the Broad-Line Region in NGC 5548 from HST and IUE Observations
Peterson, Bradley M.; Shields, Joseph C.; Pogge, Richard W. +6 more
The spatial and radial velocity distribution of broad-line--emitting gas in the Seyfert 1 galaxy NGC 5548 is examined through the process of reverberation mapping, which is done by detailed comparison of continuum and emission-line variations. Recent spectroscopic monitoring of NGC 5548 with HST and IUE allows us to resolve the "transfer function"…
Hubble Space Telescope Observations of C 2 Molecules in Diffuse Interstellar Clouds
Federman, S. R.; Lambert, David L.; Sheffer, Yaron
Interstellar C2 F-X (1342 A) and D-X (2313 A) bands in the spectrum of zeta Oph were detected using the Goddard High-Resolution Spectrograph (GHRS) on the Hubble Space Telescope (HST). The total C2 column density is (1.79 +/- 0.06) 1013/sq cm for an adopted f-value of 0.0545 for the 2313 A band of the Mulliken (D-X) system. Relative f-v…
Discovery of Candidate Cataclysmic Variables in the Post--Core-Collapse Globular Cluster NGC 6397
Cool, Adrienne M.; Cohn, Haldan N.; Lugger, Phyllis M. +2 more
A photometric search for objects with H alpha emission in the globular cluster NGC 6397 has been carried out with the Hubble Space Telescope (HST) Planetary Camera. Images were obtained through the F675W (similar to Johnson R) and F656N (H alpha) filters, and photometry carried out on approximately 900 stars detected in the central approximately 3…
Hubble Space Telescope and MERLIN Observations of the Jet in 3C 273
Muxlow, T. W. B.; Davis, R. J.; Schneider, D. P. +5 more
We present red and blue images of the jet of the quasar 3C 273 obtained with the WFPC2 on the Hubble Space Telescope as well as a new radio map made with the MERLIN array. The images are of significantly better quality than those of previous data. The two maps are aligned to an accuracy of 0."020; this accuracy is achieved because both the quasar …
The Discovery of Halley-sized Kuiper Belt Objects Using the Hubble Space Telescope
Stern, S. Alan; Levison, Harold F.; Cochran, Anita L. +1 more
We report the statistical detection (at the >99% confidence level) of a population of 28th magnitude objects exhibiting proper motions of ≈1" hr-1 at quadrature in deep Hubble Space Telescope (HST)/WFPC2 images. The drift directions imply a preponderance of objects on prograde orbits concentrated near the ecliptic plane. We interpret…
The Z = 0.8596 Damped LY alpha Absorbing Galaxy toward PKS 0454+039
Dickinson, Mark; Bowen, David V.; Steidel, Charles C. +1 more
We present Hubble Space Telescope and ground-based data on the z_abs_ = 0.8596 metal-line absorption system along the line of sight to PKS 0454+0356. The system is a moderate-redshift damped Lyα system, with N(H I) = (5.7 +/- 0.3) x 10^20^ cm^-2^ as measured from the faint Object Spectrograph spectrum. We also present ground-based images which we …
Hubble Space Telescope Observations of White Dwarfs in the Globular Cluster M4
Bond, Howard E.; Ibata, Rodrigo A.; Stetson, Peter B. +9 more
With the Wide Field Planetary Camera 2 (WFPC2) on the Hubble Space Telescope, we have discovered in M4 (NGC 6121, C1620-264) the first extensive sequence of cooling white dwarfs seen in a globular cluster. Adopting a distance modulus of (m - M)V = 12.65 and a reddening of E(B - V) = 0.37, we show that the sequence, which extends over 9 < MU <…
Composition of Interstellar Clouds in the Disk and Halo. III. HD 149881
Fitzpatrick, Edward L.; Spitzer, Lyman, Jr.
The spectrum of HD 149881, a halo star 1300 pc above the Galactic plane, has been analyzed, based on high-resolution GHRS data from Hubble Space Telescope (HST) together with 21 cm emission observations and profiles of Na I and Ca II features. The results reveal 11 absorption components, of which nine are produced in H I regions, with log N(H…
WFPC2 Imaging of the Circumstellar Nebulosity of HL Tauri
Casertano, Stefano; Ballester, Gilda E.; Krist, John E. +15 more
Planetary camera images of HL Tauri have been obtained through V-, R-, and I-band filters using the Wide Field and Planetary Camera 2 aboard the refurbished Hubble Space Telescope. These images show that HL Tauri is entirely reflection nebulosity at optical wavelengths, with no optical star visible to a limiting magnitude of V = 25.5. The optical …