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A Far-Ultraviolet Study of the Old Nova V841 Ophiuchi
Sion, Edward M.; Engle, Scott G.
We have carried out a synthetic spectral analysis of archival International Ultraviolet Explorer spectra of the old nova V841 Oph (Nova Oph 1848) taken 15 years apart. The spectra reveal a rising continuum shortward of 1560 Å, a C IV P Cygni profile indicative of wind outflow associated with disk accretion in one spectrum, a deep Lyα profile, and …
X-Ray Spectra of the Narrow-Line Seyfert 1 Galaxy Ton S180 in Comparison with Galactic Black Holes
Hong, Soojing; Kokubun, Motohide; Makishima, Kazuo +3 more
An analysis was made of 0.3-15keV X-ray spectra of a Narrow-Line Seyfert 1 Galaxy, Ton S180, using archival data from ASCA, RXTE, and XMM-Newton. At energies above 2.5keV, a power-law with a photon index of ∼ 2.3 successfully and consistently reproduced the spectra from all of these observatories. Assuming this power-law component to extend toward…
Optical and EUV observations of solar flare kernels
Doyle, J. G.; Madjarska, M. S.; Butler, C. J. +3 more
We present high-resolution spectral observations, covering the entire optical region (3800-9000 Å), of a solar flare observed during a multi-wavelength campaign. The flare, recorded on 2002 January 11, was a medium solar flare event (GOES class C7.5). The spectral observations were carried out using the Hamilton echelle spectrograph on the coudé a…
Electromagnetic Bounded States and Challenges of Plasma Spectroscopy
Fainberg, J.; Benson, R. F.; Osherovich, V. A.
Hubble Space Telescope Observations of Star-forming Regions in NGC 3994/3995
Weistrop, D.; Eggers, D.; Stone, A. +2 more
We obtained ultraviolet and optical images of star-forming regions in the interacting galaxy system NGC 3994/3995 using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. We describe the characteristics of 56 detected knots, a majority of which are younger than 20 Myr old. There is no discernible pattern of knot age with respe…
Subsurface radar sounding of the martian polar cap: radiative transfer approach
Ilyushin, Ya. A.; Seu, R.; Phillips, R. J.
The problem of subsurface radar sounding of the martian polar caps [Ilyushin, 2004. Martian northern polar cap: layering and possible implications for radar sounding. Planet. Space Sci. 52, 1195-1207] is considered from the point of view of incoherent radiative transfer theory. Since it has been previously shown that the radar signal field within …
The Seyfert-Liner Galaxy NGC 7213: An XMM-Newton Observation
Page, M. J.; Branduardi-Raymont, G.; Soria, R. +3 more
We examine the XMM X-ray spectrum of the low-ionisation nuclear emission-line region (LINER)-AGN NGC 7213, which is best fit with a power law, Kα emission lines from Fe I, Fe XXV and Fe XXVI and a soft X-ray collisionally ionised thermal plasma with kT = 0.18+0.03‑0.01 keV. We find a luminosity of 7× 10‑4 LEdd…
An overview of the scientific objectives and technical configuration of the NeUtral Atom Detector Unit (NUADU) for the Chinese Double Star Mission
Barabash, S.; Dandouras, I.; Roelof, E. C. +12 more
The scientific objectives of an advanced NeUtral Atom Detector Unit (NUADU) designed for the Chinese Double Star Polar Mission, which is scheduled for launch in July 2004, are described. The potential during this mission to realize, hitherto unprecedented, integrated studies of global dynamic magnetospheric processes through combining with NUADU d…
Far-Ultraviolet and Optical Observations of BW Vulpeculae
Smith, Myron A.; Fullerton, Alex W.; Sterken, Christiaan
We have compared the behavior of 39 Far-Ultraviolet Spectroscopic Explorer spectra through the pulsation cycle of the very large amplitude β Cephei star BW Vul with optical and UV (IUE) spectra, as well as optical photometry. The FUSE light curve suggests a temperature amplitude of about 4000 K, while the radial velocity curve is similar to corres…
Some implications of the introduction of scattered starlight in the spectrum of reddened stars
Zagury, Frédéric
This paper presents new investigations on coherent scattering in the forward direction (orders of magnitude; conservation of energy; dependence of scattered light on geometry and wavelength), and on how scattered light contamination in the spectrum of reddened stars is possibly related to as yet unexplained observations (the diminution of the 2200…