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Biconical Radiation Field and Outflow in NGC 1068: Location of the Hidden Nucleus
Arribas, S.; Mediavilla, E.; Garcia-Lorenzo, B.
Bidimensional spectroscopy of the circumnuclear region (central 10" x 8") of the Seyfert 2 galaxy NGC 1068 has been performed by means of an optical fiber system. The 95 spectra obtained simultaneously include the [N II] λλ6548, 6583, Hα, and [S II] λλ6716,6731 emission lines. In the inner regions, the velocity field obtained by cross-correlating …
Optical and ultraviolet spectrophotometry of the ONeMg Nova V838 Herculis 1991
Shore, Steven N.; Sonneborn, George; Wagner, R. Mark +2 more
We present an analysis of optical and UV spectra of the fast nova V838 Herculis 1991. IUE observations began on 1991 March 25 and continued through 1991 August 20, while optical observations began on 1991 March 29 and continued through 1991 August 20. We determine a value for the reddening of E(B-V)~0.5+/-0.1 and a distance of ~3+/-1 kpc based bot…
The Composition of the Diffuse Interstellar Medium
Fitzpatrick, Edward L.
Recent Goddard High Resolution Spectrograph measurements of Si, S, Cr, Mn, Fe, and Zn in interstellar clouds along lines of sight in the Galactic disk and into the lower halo are discussed. The gas-phase abundance of S relative to H in the interstellar clouds appears to be indistinguishable from the solar value. For the other elements, we find wel…
WFPC2 Observations of Star Clusters in the Magellanic Clouds. I. The Large Magellanic Cloud Globular Cluster Hodge 11
Fall, S. Michael; Rich, R. Michael; Mighell, Kenneth J. +1 more
We present our analysis of Hubble Space Telescope Wide Field Planetary Camera 2 observations in F555W (broadband V) and F450W (broadband B) of the globular cluster Hodge Il in the Large Magellanic Cloud galaxy. The resulting V vs B - V color-magnitude diagram reaches 2.4 mag below the main-sequence turnoff (which is at V_TO_ = 22.65+/-0.10 mag or …
Discovery of Photospheric Sulfur and Phosphorus in ORFEUS Spectra of the Hot White Dwarfs G191-B2B and MCT O455-2812
Bowyer, Stuart; Vennes, Stephane; Chayer, Pierre +1 more
High-dispersion observations of the far-ultraviolet (FUV) spectra of the hot DA white dwarfs G191-B2B and MCT 0455-2812 reveal the presence of two previously undetected elements in white dwarf photospheres: sulfur and phosphorus. The spectra, obtained with the Berkeley EUV/FUV spectrometer and the ORFEUS telescope aboard the space platform Astro-S…
Heliospheric plasma sheets as small-scale transients
Balogh, A.; Crooker, N. U.; Burton, M. E. +2 more
Ulysses plasma and magnetic field data from the ecliptic plane near 1 AU signaling multiple heliospheric plasma sheets across a sector boundary are analyzed in order to determine their geometrical configuration. The plasma sheets coincided with a region of sporadic heat flux dropouts and planar magnetic structure. The plane of the structure was in…
The X-ray and EUV spectrum of the dwarf nova VW Hydri in outburst and quiescence.
Belloni, T.; Verbunt, F.; Watson, M. G. +5 more
We combine ROSAT, Ginga, and EXOSAT observations to investigate the X-ray and extreme-ultraviolet fluxes of VW Hyi in quiescence and throughout an ordinary dwarf-nova outburst. We show that the quiescent spectrum is consistent with emission from material heated to ~12keV and cooling through the X-ray band to temperatures below our sensitivity rang…
Physical Conditions in Low Ionization Regions of the Orion Nebula
Martin, P. G.; Crotts, A.; O'Dell, C. R. +12 more
We reexamine the spectroscopic underpinnings of recent suggestions that [O I] and [Fe II] lines from the Orion H II region are produced in gas where the iron-carrying grains have been destroyed and the electron density is surprisingly high. Our new observations show that previous detections of [O I] 5577 were dominated by telluric emission. Our li…
Interstellar propagation of cosmic rays: analysis of the ULYSSES primary and secondary elemental abundances.
Duvernois, M. A.; Simpson, J. A.; Thayer, M. R.
The purpose of this investigation is to study the validity of the "leaky box" propagation model and determine some of its parameters. The pathlength distributions and their energy dependencies are derived from measurements of secondary-to-primary abundance ratios. A special charged particle telescope carried on the Ulysses spacecraft has provided …
The Discovery and Orbit of 1993 (243)1 Dactyl
Petit, Jean-Marc; Mueller, Beatrice E. A.; Neukum, Gerhard +18 more
Dactyl was discovered in solid state imaging (SSI) data on February 17, 1994, during the long playback of approach images from the Galileo spacecraft's encounter with the asteroid 243 Ida. Forty-seven images of the Ida-Dactyl pair were obtained. A detailed search for other satellites was made. No confirmed detections were made, all other candidate…