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Modeling IR spectra of OH/IR stars at different phases
Suh, Kyung-Won; Kim, H. -Y.
We investigate the spectral energy distributions (SEDs) of OH/IR stars (OH127.8+0.0 and OH26.5+0.6) having thick dust envelopes at different pulsation phases. Using new infrared observational data including the Infrared Space Observatory (ISO) data, we determine the new pulsation parameters. The deep silicate absorption features show significant v…
A Uniform Analysis of the Lyα Forest at z = 0-5. IV. The Clustering and Evolution of Clouds at z <= 1.7
Bechtold, Jill; Dobrzycki, Adam; Scott, Jennifer +1 more
We present results on the evolution and clustering of Lyα lines at low redshift as part of our series ``A Uniform Analysis of the Lyα Forest at z=0-5.'' The sample analyzed in this paper contains 1298 Lyα absorption lines from 165 quasar spectra mined from the archives of the Faint Object Spectrograph on the Hubble Space Telescope (HST). Our sampl…
The Search for Intergalactic Hydrogen Clouds in Voids
Manning, Curtis V.
I present the results of a search for intergalactic hydrogen clouds in voids. Clouds are detected by their H I Lyα absorption lines in the Hubble Space Telescope spectra of low-redshift active galactic nuclei. The parameter with which the environments of clouds are characterized is the tidal field, for this places a lower limit on the cloud mass d…
Study of the nonradial directional property of the rays of the streamer belt and chains in the solar corona
Eselevich, M. V.; Eselevich, V. G.
Based on analyzing corona images taken by the LASCO C1, C2, and C3 instruments, a study is made of the behavior of the streamer belt spanning one half of the 1996-2001 cycle of solar activity, from minimum to maximum activity, in the absence of coronal mass ejections. It is shown that: (1) The position of the streamer belt relative to the solar eq…
The Capella Giants and Coronal Evolution across the Hertzsprung Gap
Young, P. R.; Kriss, G. A.; Dupree, A. K. +5 more
We present an analysis of the coronal line Fe XXI λ1354 observed in medium-resolution Hubble Space Telescope/Space Telescope Imaging Spectrograph echelle spectra of Capella obtained on 1999 September 12. These data were collected in support of a multiwavelength spectroscopic campaign designed to provide detailed temperature and density diagnostics…
Diffraction-limited bispectrum speckle interferometry of the Herbig Be star R Mon
Weigelt, G.; Hofmann, K. -H.; Preibisch, T. +1 more
We explore the structures immediately surrounding the intermediate-mass young stellar object R Mon with bispectrum speckle interferometry, conventional near-infrared imaging and by analyzing optical HST archive data. Our near-infrared speckle images with unprecedented diffraction-limited resolution of 55 mas ( ~ 44 AU; H-band) and 76 mas ( ~ 61 AU…
Solar Disappearing Filament Inside a Coronal Hole
Hudson, H. S.; Chertok, I. M.; Obridko, E. I. +2 more
Based on Yohkoh/SXT, SOHO/EIT images and movies, as well as on Hα, He I 10830 Å heliograms and other relevant data, we analyze an event of 1999 December 28, which is interesting in at least two aspects. (1) A major horseshoe-shaped Hα filament appeared to be located within a large transequatorial coronal hole (CH) in the eastern hemisphere. (2) Th…
A New Empirical Method for Estimating the Far-Infrared Flux of Galaxies
Onaka, Takashi; Takeuchi, Tsutomu T.; Shibai, Hiroshi +1 more
We propose a new empirical method to estimate the total far-infrared flux of galaxies from the spectral energy distribution (SED) at wavelengths of λ <= 100 µm. It is difficult to derive the total far-infrared luminosity from only the IRAS data, though it is one of the most important properties of galaxies. Observations by Infrared Telesc…
Discovery of 15 Second Oscillations in Hubble Space Telescope Observations of WZ Sagittae following the 2001 Outburst
Knigge, C.; Marsh, T. R.; Long, K. S. +3 more
We report the discovery of 15 s oscillations in ultraviolet observations of WZ Sagittae obtained with the Hubble Space Telescope approximately 1 month after the peak of the 2001 outburst. This is the earliest detection of oscillations in WZ Sge following an outburst and the first time that a signal near 15 s has been seen to be dominant. The oscil…
An irradiated accretion disc in the narrow-line Seyfert 1 RE J1034+396?
Soria, R.; Puchnarewicz, E. M.
We model the optical to X-ray continuum spectrum of the narrow-line Seyfert 1 galaxy RE J1034+396. We show that the flat optical spectrum is consistent with emission from an irradiated accretion disc. The X-ray emission can be modelled with a disc blackbody and a Comptonized component. The temperature at the inner edge of the disc Tin=(…