Search Publications
A search for hidden white dwarfs in the ROSAT extreme ultraviolet survey
Barstow, M. A.; Burleigh, M. R.; Fleming, T. A.
The ROSAT Wide Field Camera survey has provided us with evidence for the existence of a previously unidentified sample of hot white dwarfs (WDs) in non- interacting binary systems, through the detection of extreme ultraviolet (EUV) and soft X-ray emission. These stars are hidden at optical wavelengths because of their close proximity to much more …
A theoretical approach to globular cluster low main sequence stars.
Cassisi, S.; Castellani, V.; degl'Innocenti, S. +3 more
This paper present new evolutionary computations extending toward the lower main sequence previous computations given for globular cluster stars. We discuss the physical inputs with particular regard to the limit of the adopted usual treatment of the stellar atmosphere, which allows a tight correlation with actual stellar structures only for selec…
ULYSSES observations of intermittent heliospheric turbulence
Balogh, A.; Horbury, T. S.; Forsyth, R. J. +1 more
Structure function measurements of small scale magnetic field fluctuations in high speed streams emanating from the Sun's polar coronal holes are well described by a multifractal model of intermittent turbulence. We discuss structure functions and present measurements of intermittency through the transition regime - encompassing scales between wav…
[Fe IV] in the Orion Nebula
Martin, P. G.; O'Dell, C. R.; Dufour, R. J. +6 more
Using the Goddard High-Resolution Spectrograph on the Hubble Space Telescope, we measured the flux of [Fe IV] (3d5 4P5/2 --> 3d5 6S5/2) λvac = 2836.56 Å in the Orion Nebula, the first detection of an [Fe IV] line in an H II region. A useful upper limit is set on the su…
Mesures de vitesses radiales. VIII. Accompagnement AU sol du programme d'observation du satellite HIPPARCOS
Duflot, M.; Burnage, R.; Genty, V. +2 more
We publish 1879 radial velocities of stars distributed in 105 fields of 4^{\circ} \times 4^{\circ}. We continue the PPO series \cite[(Fehrenbach et al. 1987;]{Feh87} \cite[Duflot et al. 1990, 1992 and 1995),]{Du90} using the Fehrenbach objective prism method. Table 1 only available in electronic form at CDS via to cdsarc.u-strasbg.fr (130.79.128.5…
The gravitational lensing nature of the Cloverleaf unveiled in CO (7-6) line emission.
Antonucci, R.; Tacconi, L.; Alloin, D. +2 more
We report 0.5" resolution imaging of the Cloverleaf quasar in the CO(7-6) line and 1.3mm continuum,, as well as 1" resolution imaging in the CO(3-2) line, performed with the IRAM interferometer. The CO(7-6) image is clearly resolved into 4 spots, demonstrating that the CO emission is also gravitationally lensed. We do not find any convincing evide…
Influence of heavy ions on the high-speed solar wind
Li, Xing; Habbal, Shadia R.; Esser, Ruth +1 more
We present the results of a parameter study of the influence of heavy ions on the background solar wind, choosing doubly ionized helium, or alpha particles, and O+6, as examples. Using a three-fluid solar wind model, we keep the input parameters to the electrons and protons unchanged and investigate the effects of changing the input ene…
Absolute Flux Distributions of Solar Analogs from the UV to the Near-IR
Colina, Luis; Bohlin, Ralph
The 0.225-2.695mu m absolute flux distributions of the solar analogs P041C, P177D, and P330E are presented. The ultraviolet and optical wavelength range from 0.225mu m to 0.825mu m is based on high signal-to-noise spectra obtained with the HST Faint Object Spectrograph (FOS). The spectra in the near-infrared longward of 0.825mu m are scaled versio…
Diffusive Shock Acceleration in Oblique Magnetohydrodynamic Shocks: Comparison with Monte Carlo Methods and Observations
Jones, T. W.; Kang, Hyesung
We report simulations of diffusive particle acceleration in oblique magnetohydrodynamical (MHD) shocks. These calculations are based on extension to oblique shocks of a numerical model for ``thermal leakage'' injection of particles at low energy into the cosmic-ray population. That technique, incorporated into a fully dynamical diffusion-convectio…
Nuclear Properties of Kinematically Distinct Cores
Rich, R. Michael; Carollo, C. Marcella; Danziger, I. John +1 more
We present WFPC2 F450W, F555W, and F814W photometry for three early-type galaxies with kinematically distinct cores (KDCs), namely NGC 2434, NGC 7192, and IC 4889. For these three objects we present the B, V, and I nuclear surface brightness, isophotal, B-V and V-I profiles and derive the deprojected luminosity densities. The three KDCs have nucle…