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Terminal Speeds and Ion Fractions from [Ca IV] 3.207 µm in Three Single WN Stars
Ignace, R.; Cassinelli, J. P.; Babler, B. +1 more
We report on the forbidden emission lines of [Ca IV] at 3.207 µm and [Ne III] at 15.56 µm based on Infrared Space Observatory observations. The data set consists of three single Wolf-Rayet stars (WR 1, WR 134, and WR 136) and three binary systems (WR 11, WR 146, and WR 147). For the single stars, only the [Ca IV] line was observed. Our…
Testing Hydrodynamic Models of LMC X-4 with Ultraviolet and X-Ray Spectra
Boroson, Bram; Kallman, Timothy; Blondin, John M. +1 more
We compare the predictions of hydrodynamic models of the LMC X-4 X-ray binary system with observations of UV P Cygni lines with the Goddard High Resolution Spectrograph and Space Telescope Imaging Spectrograph on the Hubble Space Telescope. The hydrodynamic model determines density and velocity fields of the stellar wind, wind-compressed disk, acc…
Detection of the Faint Companion in the Massive Binary HD 199579
Bolton, C. T.; Fullerton, A. W.; Gies, D. R. +14 more
We present new radial velocity data for the massive binary HD 199579 O6 V((f)) based upon spectra obtained from IUE, the Canada-France-Hawaii Telescope, KPNO, the David Dunlap Observatory, and the GSU Multiple-Telescope Telescope. We derive a revised period, P=48.5216+/-0.0015 days, and improved orbital elements that agree with the earlier element…
A Burst from the Direction of UZ Fornacis with XMM-Newton
Mukai, Koji; Still, Martin
The XMM-Newton pointing toward the magnetic cataclysmic variable UZ For finds the source to be a factor of greater than 103 fainter than previous EXOSAT and ROSAT observations. The source was not detected for the majority of a 22 ks exposure with the European Photon Imaging Cameras, suggesting that the accretion rate either decreased or…
X-Ray and Ultraviolet Orbital Phase Dependence in LMC X-3
Boyd, Patricia T.; Smale, Alan P.; Dolan, Joseph F.
The black hole binary LMC X-3 is known to be variable on timescales of days to years. We investigate X-ray and ultraviolet variability in the system as a function of the 1.7 day binary phase using a 6.4 day observation with the Rossi X-Ray Timing Explorer (RXTE) from 1998 December. An abrupt 14% flux decrease, lasting nearly an entire orbit, is fo…
Center-to-Limb Angle Dependence of Phases (v, δ|B|) Observed with the Michelson Doppler Imager
Liu, Y.; Ulrich, R. K.; Norton, A. A.
We test the hypothesis that phases between line-of-sight magnetic and velocity signals depend upon center-to-limb angle if the magnetic response to photospheric velocity perturbations is both magneto-acoustic and Alfvénic. The Michelson Doppler Imager observes two bipolar active regions. Sunspots exhibit the predicted shift toward phase angles of …
Models of the Shoemaker-Levy 9 Impacts. I. Ballistic Monte Carlo Plume
Deming, Drake; Harrington, Joseph
We model the plumes raised by impacting fragments of comet Shoemaker-Levy 9 to calculate synthetic plume views, atmospheric infall fluxes, and debris patterns. Our plume is a swarm of ballistic particles with one of several mass-velocity distributions (MVDs). The swarm is ejected instantaneously and uniformly into a cone from its apex. On falling …
The Host Galaxy and Environment of the z=1.195 Quasar 3C 190
Stockton, Alan; Ridgway, Susan E.
We present deep imaging and spectroscopic observations of the z=1.195 quasar 3C 190 and its immediate environment. The quasar is surrounded by an asymmetric, low surface brightness envelope in which there are also several galaxies with characteristic dimensions of 3-5 kpc. Some of these form a linear structure some 50 kpc long in projection, offse…
Long-Term Multiwavelength Observations of GRS 1758-258 and the Advection-dominated Accretion Flow Model
Hailey, Charles J.; Kahn, Steven M.; Craig, William W. +9 more
We present a long-term multiwavelength light curve of Galactic black hole candidate GRS 1758-258 by combining previously published and archival data from Granat, ROSAT, the Compton Gamma Ray Observatory, the Rossi X-Ray Timing Explorer, BeppoSAX, ASCA, EXOSAT, and the Very Large Array. In addition, we include the first spectral results from the ba…
Extent of Excess Far-Infrared Emission around Luminosity Class III Stars
Zuckerman, B.; Kim, Sungsoo S.; Silverstone, Murray
With the Infrared Space Observatory, we conducted 3×3 pixel imaging photometry of 12 luminosity class III stars, which were previously presumed to have dust particles around them, at far-infrared wavelengths (60 and 90 µm). Eleven out of 12 targets show a peak of excess (above photosphere) far-infrared emission at the location of the star, i…