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The Ultraviolet Imaging Telescope: Instrument and Data Characteristics
O'Connell, R. W.; Bohlin, R. C.; Stecher, T. P. +16 more
The Ultraviolet Imaging Telescope (\UIT) was flown as part of the \AstroMiss\ observatory on the Space Shuttle Columbia in December 1990 and again on the Space Shuttle Endeavor in March 1995. Ultraviolet (1200-3300\AA) images of a variety of astronomical objects, with a 40\arcmin\ field of view and a resolution of about 3\arcsec, were recorded on …
Detailed Non-LTE Model Atmospheres for Novae during Outburst. I. New Theoretical Results
Baron, E.; Shore, Steven N.; Hauschildt, Peter H. +3 more
We present new, detailed non-LTE (NLTE) calculations for model atmospheres of novae during outburst. This fully self-consistent NLTE treatment for a number of model atoms includes 3922 NLTE levels and 47,061 NLTE primary transitions. We discuss the implication of departures from LTE for the strengths of the lines in nova spectra. The new results s…
GHRS Monitoring of the Outflowing Material in NGC 4151
Morris, Simon L.; Hutchings, John B.; Weymann, Ray J. +1 more
We present the results of a program to monitor the absorption lines in the spectrum of the Seyfert 1 galaxy NGC 4151 caused by outflowing gas from the nucleus. Spectral observations were taken in the UV with the GHRS and FOS of HST. GHRS G160M and G270M exposures were taken of the wavelength regions centered on C IV and Mg II, respectively, extend…
Quantitative analysis of the FUV, UV and optical spectrum of the O3 star HD 93129A.
Butler, K.; Lennon, D. J.; Kudritzki, R. P. +6 more
A quantitative analysis of the extremely hot and massive galactic O3If^*^ supergiant HD 93129A is carried out using stellar wind and pseudo photospheric lines observed in the FUV, UV and optical spectrum together with hydrodynamical NLTE model atmospheres. The analysis in the FUV is combined with spectrum synthesis of the molecular and atomic/ioni…
The Mg/Ne abundance ratio in a recently emerged flux region observed by CDS
Young, P. R.; Mason, H. E.
Evidence for the existence of the FIP-effect in the transition region is presented here based on recent observations from the Coronal Diagnostic Spectrometer (CDS) on-board the Solar and Heliospheric Observatory (SOHO). Observations of an emerging flux region in lines of Mgv-vii and Nevi-vii reveal differences in the relative Mg/Ne abundance of a …
The Abundance of Interstellar Krypton
Meyer, David M.; Cardelli, Jason A.
We present high signal-to-noise ratio HST Goddard High Resolution Spectrograph (GHRS) observations of the weak interstellar Kr I λ1236 absorption toward the stars τ CMa, κ Ori, ɛ Ori, λ Ori, δ Sco, ω1 Sco, ɛ Per, and ζ Per. In combination with previous GHRS measurements of Kr I in two other sight lines (ζ Oph and 1 Sco), these new obser…
Doppler Shifts and Nonthermal Broadening in the Quiet Solar Transition Region: O VI
Wilhelm, K.; Lemaire, P.; Mariska, J. T. +1 more
Using observations from the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) experiment flown on the Solar and Heliospheric Observatory (SOHO) spacecraft, we have measured Doppler wavelength shifts and nonthermal broadening in the 1032 and 1038 Å emission lines of O VI and the 1036 and 1037 Å emission lines of C II. Near Sun center the …
New Wavelength Determinations of Mid-Infrared Fine-structure Lines by Infrared Space Observatory Short Wavelength Spectrometer
Lutz, D.; Heras, A. M.; Beintema, D. A. +18 more
We report accurate new wavelengths for 29 mid-infrared ionic fine-structure lines, based on observations with the Short Wavelength Spectrometer (SWS) on board the Infrared Space Observatory (ISO). Our results originate from observations of NGC 7027, NGC 6543, NGC 6302, the Circinus galaxy, Sgr A West, and W51 IRS 2. The obtained accuracies (λ/Δλ) …
High-Resolution Ultraviolet Observations of the Highly Ionized Interstellar Gas toward Radio Loops I and IV
Tripp, Todd M.; Sembach, Kenneth R.; Savage, Blair D.
We present new Goddard High-Resolution Spectrograph (GHRS) echelle observations of the high ionization lines of Si IV, C IV, and N V toward HD 119608, a halo star at d = 4.1 kpc behind the Loop I and IV supernova remnants. Absorption along the path to HD 119608 makes it possible to study energetic processes that may result in the flow of gas into …
A starburst origin of the OH-megamaser emission from the galaxy Arp220
Sturm, E.; Barlow, M. J.; Stacey, G. J. +3 more
Ultraluminous infrared galaxies have been known for more than a decade, but the source of their very large far-infrared luminosities remains controversial. It may reflect a quasar-like active nucleus surrounded by a torus of dense gas and dust, the latter absorbing the energetic photons from the nuclear region and re-emitting at infrared wavelengt…