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The Hubble Space Telescope Quasar Absorption Line Key Project. I. First Observational Results, Including Lyman-Alpha and Lyman-Limit Systems

Turnshek, David A.; Schneider, Donald P.; Savage, Blair D. +9 more

We present spectra for a total of 37 quasars with small and moderate redshifts; the quasars were observed with the Faint Object Spectrograph of the Hubble Space Telescope. The spectra are obtained either at a resolution of R = 1300 (hereafter "higher resolution") or a resolution of r = 180 (hereafter "lower resolution"). We report new higher resol…

The Hubble Space Telescope Quasar Absorption Line Key Project. II. Data Calibration and Absorption-Line Selection

Turnshek, David A.; Schneider, Donald P.; Savage, Blair D. +10 more

We present the observational and data processing aspects of the Hubble Space Telescope Quasar Absorption Line Key Project. Topics discussed include the observational technique, calibration of the data, software that simulates the data, the automated procedure used to identify and characterize the absorption features, and the determination of the s…

The Structure of the Core of 47 Tucanae from Hubble Space Telescope Observations

Ferraro, Francesco R.; Paresce, Francesco; de Marchi, Guido

A set of moderately deep, high-resolution images of the core of the Galactic globular cluster NGC 104 (47 Tucanae) taken by the Faint Object Camera F/48 relay on the Hubble Space Telescope through the filters F140W, F220W, and F342W are presented and analyzed. The core is completely resolved in these bands for the first time, with approximately 35…

Star Counts from the Hubble Space Telescope Snapshot Survey. I. Galactic Models

Gould, A.; Maoz, D.; Bahcall, J. N.

We report on a photometric study of stars from 450 fields at high Galactic latitudes that were observed in the Hubble Space Telescope Snapshot Survey to an average limiting apparent magnitude of V = 21.4. There are 166 fields that contain quasars selected in radio, X-ray, and color-excess surveys. This sample of 273 stars is free of selection bias…