Search Publications
Color and Morphology of Galaxies in the Region of the 3C 324 Clusters at z ~ 1.2
Yamada, Toru; Kajisawa, Masaru
We investigated the color and morphology of optically selected galaxies in the region of clusters at z ~ 1.2 near to the radio galaxy 3C 324 using archived data taken with the Hubble Space Telescope. The faint galaxies selected at the HST F702W band that contribute to the surface-density excess of the region have wide ranges of color, size, and mo…
Limb profiles of the Moon obtained from grazing occultation observations.
Soma, M.
Observations of lunar grazing occultations were analyzed using the Hipparcos Catalogue of stars and the JPL planetary and lunar ephemerides DE405, and lunar limb profile data were obtained for future grazing occultation observations. These profile data will be used for the analysis of solar eclipse observations to detect the variation of the solar…
Variations in the ratio of particle to magnetic field energy density, as observed by Ulysses/HI-SCALE
Daglis, I.; Sidiropoulos, N.; Sarris, E. +3 more
The photometric variability of the Be star NW Serpentis
Harmanec, P.; Percy, J. R.; Marinova, M. M. +1 more
{NW Ser} is a bright (V = 6.1 - 6.2) active Be star which is known to vary photometrically on a time scale of hours to days. Using both Hipparcos and ground-based photometry, and using light curve, autocorrelation, power spectrum analysis and phase dispersion minimalization techniques, we have concluded that the period is close to 0.46d - a period…
Fast solar wind acceleration by Alfvén waves: observable effects on the EUV lines detected by SOHO/UVCS
Orlando, S.; Peres, G.; Spadaro, D. +1 more
SOHO/UVCS observations of the most intense EUV spectral lines emitted by the solar corona have been providing us a good opportunity to study in detail the acceleration regions of the solar wind. In this work we aim at deriving useful diagnostics and identifying possible signatures of Alfvén waves momentum deposition. More specifically we investiga…
On the Electron Temperature and Coronal Heating in the Fast Solar Wind Constrained by in-situ Observations
Ko, Y. -K.; Groth, C. P. T.
The electron temperature profile in the polar coronal hole inferred by the ionic charge state data of the fast wind exhibits a local maximum of ∼ 1.5 × 106 K. This indicates the existence of electron heating in the source region of the fast solar wind. In this paper, a two-fluid solar wind model, which incorporates additional 'mechanica…
Review, based on particles and fields observations made aboard the Giotto spacecraft, concerning the nature of the solar wind interaction with comets P/Halley and P/Grigg Skjellerup
McKenna-Lawlor, Susan M. P.
A key driver underlying the decision to command the Giotto spacecraft on to an encounter with comet P/Grigg-Skjellerup following its highly successful encounter with P/Halley, was the unique scientific opportunity this provided to compare measurements made using the same suite of plasma and fields instruments at (a) very active and 'fresh' comet P…
Large-scale Coronal Heating, Clustering of Coronal Bright Points, and Concentration of Magnetic Flux
Falconer, D. A.; Moore, R. L.; Porter, J. G. +1 more
By combining quiet-region Fe XII coronal images from SOHO/EIT with magnetograms from NSO/Kitt Peak and from SOHO/MDI, we show that the population of network coronal bright points and the magnetic flux content of the network are both markedly greater under the bright half of the large-scale quiet corona than under the dim half. These results (1) su…
IRAS 17393-3004, a late-type supergiant surrounded by a dust shell
Zylka, R.; Tuffs, R. J.; Philipp, S. +1 more
Infrared observations of IRAS 17393-3004, including a full scan ISOSWS are presented. The ISOSWS spectrum shows two prominent dust emission peaks at lambda 10.4mu m and 17.5 mu m confirming that the source is a luminous star surrounded by a dust shell. The spectrum of the star, deduced from modeling of the radiative transfer through a spherical sh…
Stellar C III Emissions as a New Classification Parameter for [WC] Central Stars
Feibelman, Walter A.
We report detection of stellar C III λ1909 emission in IUE echelle spectra of early-type [WC] central stars of planetary nebulae (CSPNs). Additionally, stellar C III emission at 2297 Å is observed in early- and late-type [WC] CSPNs. Inclusion of these C III features for abundance determinations may resolve a conflict of underabundance of C/O for e…