Search Publications
Discovery of New Objects in the Orion Nebula on HST Images: Shocks, Compact Sources, and Protoplanetary Disks
O'Dell, C. R.; Wen, Zheng; Hu, Xihai
We have reduced and analyzed a set of narrow-band HST images of a portion of M42 south of the Trapezium. Many new emission-line sources were found, some quite long but so narrow that they are not seen on ground-based images. These include thin shells which are high-ionization shocks. The structure around Orion HH 3 is resolved into multiple compon…
Goddard High-Resolution Spectrograph Observations of the Local Interstellar Medium and the Deuterium/Hydrogen Ratio along the Line of Sight toward Capella
Ayres, Thomas R.; Savage, Blair D.; Brown, Alexander +6 more
HST Goddard High-Resolution Spectrograph observations of the 1216, 2600, and 2800 A spectral regions are analyzed for the spectroscopic binary system Capella, obtained at orbital phase 0.26 with 3.27-3.57 km/s resolution and high SNR. The column densities of H I, D I, Mg II, and Fe II for the local interstellar medium along this 12.5 pc line of si…
Early-Type Galaxies, Dark Halos, and Gravitational Lensing Statistics
Maoz, Dan; Rix, Hans-Walter
We present calculations of the expected statistics of gravitational lensing of quasars in the Hubble Space Telescope snapshot survey. We first model early-type (elliptical and SO) galaxies using their observed surface brightness profiles and dynamically inferred mass-to-light ratios. Our work improves upon previous calculations, which have general…
Composition of Interstellar Clouds in the Disk and Halo. I. HD 93521
Fitzpatrick, Edward L.; Spitzer, Lyman, Jr.
Interstellar column densities of Fe, S, Si, Mn, and Mg in their dominant ionization state, as well as of C(+) and S(2+), are presently derived from analyses of HST UV observations of the Galactic halo star HD 93521. Ratios of column densities for the dominant species yield approximations of the logarithmic depletion D(X) in the warm, primarily neu…
SN 1992A: Ultraviolet and Optical Studies Based on HST, IUE, and CTIO Observations
Suntzeff, N. B.; Fransson, Claes; Challis, Peter M. +18 more
The Type Ia supernova SN 1992A in the 50 galaxy NGC 1380 was observed as a target of opportunity by the International Ultraviolet Explorer (IUE) and with great alacrity by the Hubble Space Telescope (HST). Here we present the HST and lUE spectra and photometry that we obtained, as well as optical spectra obtained at the Cerro Tololo Inter-American…
Hubble Space Telescope Imaging of the Narrow-Line Region of NGC 4151
Ford, H. C.; Kriss, G. A.; Evans, I. N. +3 more
We have used the Planetary Camera aboard the Hubble Space Telescope to obtain high spatial resolution [O III] λ5007 and Hα λ6563 + [N II] λλ6548, 6583 images of the nucleus of NGC 4151. Almost all of the Hα λ6563 + [N II] λλ6548, 6583 emission arises from an unresolved nuclear point source. The [O III] λ5007 image resolves the narrow-line region i…
The Ionization Cones in the Seyfert Galaxy NGC 5728
Krolik, J. H.; Wilson, A. S.; Heckman, T. M. +2 more
We report high-resolution (0.1") observations of the Seyfert 2 galaxy NGC 5728 with the Hubble Space Telescope. Images have been obtained in the light of [O III] λλ4959, 5007, Hα+[N II] λλ6548, 6583 and green and red continua. The emission-line images reveal a spectacular biconical structure with overall extent 1.8 kpc. The two cones share a commo…
Abundance of Interstellar Carbon toward zeta Ophiuchi
Ebbets, Dennis C.; Savage, Blair D.; Cardelli, Jason A. +1 more
We report on the detection of the weak intersystem transition of semiforbidden C II 2325 A in the sight line toward Zeta Oph using the Ech-B mode of the Goddard High-Resolution Spectrograph. The measured equivalent width of the semiforbidden C II line is W(lambda) = 0.52 +/- 0.12 mA, implying a C II column density of 1.80 (+/- 0.42) x 10 exp 17 at…
The Hubble Space Telescope Snapshot Survey. IV. A Summary of the Search for Gravitationally Lensed Quasars
Gould, A.; Maoz, D.; Meylan, G. +7 more
We report the concluding results of the HST Snapshot Survey for gravitationally lensed quasars. New observations of 153 high-luminosity z > 1 quasars are presented, bringing to 498 the total number of quasars observed in the survey. The new observations do not reveal new candidates for gravitational lensing. We present tables summarizing all of…
The Crab Pulsar in the Visible and Ultraviolet with 10 Microsecond Time Resolution
Dolan, J. F.; Nelson, M. J.; Percival, J. W. +8 more
Observations of PSR 0531+21 with the High Speed Photometer on the HST in the visible in October 1991 and in the UV in January 1992 are presented. The time resolution of the instrument was 10.74 microsec; the effective time resolution of the light curves folded modulo the pulsar period was 21.5 microsec. The main pulse arrival time is the same in t…