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Hubble Space Telescope and VLA Observations of Seyfert 2 Galaxies: The Relationship between Radio Ejecta and the Narrow-Line Region
Simpson, Chris; Wilson, Andrew S.; Falcke, Heino
We present HST/WFPC2 images, in narrowband filters containing the [O III] λ5007 and Hα + [N II] emission lines and their adjacent continua, of a sample of seven Seyfert 2 galaxies selected because they possess either extended emission-line regions in ground-based observations or a hidden broad-line region in polarized light. Six of the galaxies ha…
Abundances of Deuterium and Helium-3 in the Protosolar Cloud
Geiss, J.; Gloeckler, G.
The mass spectrometric determinations of the isotopic composition of helium in the solar wind obtained from (1) the Apollo Solar Wind Composition (SWC) experiment, (2) the Ion Composition Instrument (ICI) on the International Sun Earth Explorer 3 (ISEE-3), and (3) the Solar Wind Composition Spectrometer (SWICS) on Ulysses are reviewed and discusse…
Imaging of the EGG Nebula (CRL 2688) with WFPC2/HST: A History of AGB/Post--AGB Giant Branch Mass Loss
Holtzman, J. A.; Gallagher, J. S., III; Clarke, J. T. +14 more
The proto-planetary nebula, CRL 2688, has been imaged through a wideband filter centered at 606 nm (F606W) with the Wide Field Planetary Camera 2 onboard the Hubble Space Telescope. CRL 2688 is the prototypical bipolar reflection nebula in which a star is surrounded by a dense, flattened cocoon of dust seen nearly edge-on and starlight escapes pre…
Spatial structure of the solar wind and comparisons with solar data and models
Hoeksema, J. T.; Galvin, A. B.; Steinberg, J. T. +10 more
Data obtained by instruments on the Ulysses spacecraft during its rapid sweep through >90° of solar latitude, crossing the solar equator in early 1995, were combined with data obtained near Earth by the Wind spacecraft to study the spatial structure of the solar wind and to compare to different models of the interplanetary magnetic field derive…
Starburst-like Dust Extinction in the Small Magellanic Cloud
Gordon, Karl D.; Clayton, Geoffrey C.
The recent discovery that the ultraviolet (UV) dust extinction in starburst galaxies is similar to that found in the Small Magellanic Cloud (SMC) motivated us to reinvestigate the UV extinction found in the SMC. We have been able to improve significantly on previous studies by carefully choosing pairs of well-matched reddened and unreddened stars.…
M32 +/- 1
Lauer, Tod R.; Ajhar, Edward A.; Faber, S. M. +2 more
Multicolor HST WFPC2 images are used to study the central structure of the three Local Group galaxies M31, M32, and M33. PSF deconvolution and modeling of image aliasing are required to recover accurate brightness profiles within r < 0.5". The data present a study in contrasts that suggests different evolutionary histories. In M31, the nucleus …
Ultraviolet-Optical Observations of the Seyfert 2 Galaxies NGC 7130, NGC 5135, and IC 3639: Implications for the Starburst-Active Galactic Nucleus Connection
Heckman, Timothy; Leitherer, Claus; Wilson, Andrew S. +5 more
We present and discuss Hubble Space Telescope (HST) (WFPC2 and FOC) images and ultraviolet (GHRS) spectra plus ground-based optical spectra of three Seyfert 2 nuclei (NGC 7130, NGC 5135 and IC 3639). These galaxies, together with Mrk 477 (Heckman et al.), were selected on the basis of ultraviolet brightness from a bigger sample that comprises the …
The dark side of star formation in the Antennae galaxies
Cesarsky, C.; Duc, P. -A.; Madden, S. C. +6 more
We compare mid-infrared images of the Antennae galaxies (NGC4038/39) from the Infrared Space Observatory, with optical images from the Hubble Space Telescope. The mid-infrared observations show that the most intense starburst in this colliding system of galaxies takes place in an off-nucleus region that is inconspicuous at optical wavelengths. The…
A spectral decomposition of the variable optical, ultraviolet and X-ray continuum of NGC 5548
Zdziarski, Andrzej A.; Smith, David A.; Johnson, W. Neil +2 more
We present an analysis and decomposition of the broad-band optical/UV/X-ray/gamma-ray spectrum of the Seyfert 1 galaxy NGC 5548. The spectrum consists of an average of simultaneous optical/IUE/Ginga observations accompanied by ROSATCGRO/OSSE data from non-simultaneous observations. We show that the overall optical/UV/X-ray/gamma-ray spectrum can b…
A HST spectroscopic study of QSOs with intermediate redshift damped Lyalpha systems
Deharveng, Jean-Michel; Bergeron, Jacqueline; Le Brun, Vincent +1 more
We present HST spectra for a sample of six QSOs with intermediate redshift (z_ale 1.) damped Lyalpha systems. These observations aim at measuring the Hi column density and detect metal lines in order to investigate the metal enrichment of the gas, as well as the presence of neutral species, molecules and dust. All systems selected on the basis of …