Search Publications
An Extremely Thin Gravitational Arc Formed by the Distant Cluster CL 0016+1609: Lensing of a Compact HDF-Type Object?
Lavery, Russell J.
Hubble Space Telescope WFPC2 images of the core of the distant cluster of galaxies CL 0016+1609 (z =0.545) have revealed a single extremely thin faint arc, likely produced by gravitational lensing of a very distant background galaxy. The arc, which we refer to as Arc-1, is ~3.5 arcsec in extent, has a radius of curvature of 25+/-5 arcsec, and subt…
The mass and angular momentum loss from the edge of the accretion disk and the evolution of cataclysmic binaries
Yu, K. N.; Huang, Run-qian
We give the mass and angular momentum loss from the edge of the accretion disk of a cataclysmic binary and model theoretically the effect of these losses on the evolution of the system. The results of the calculation show that the high-velocity mass outflows observed by IUE come from the edge of the disk and the angular momentum loss there could b…
The Broad Emission Line Region in AGNs and Quasars: The Impact of Variability Studies
Gondhalekar, P. M.; O'Brien, P. T.; Goad, M. R.
Coordinated observations of variability of the continuum and the emission-line luminosities (reverberation mapping) in AGNs and quasars have fundamentally altered our understanding of the broad-line regions in active galaxies. The constraints these observations impose on the models of the BLRs have been demonstrated here by an attempt to model the…
The quasi-parallel shock wave detected by ULYSSES on day 92:109.
Balogh, A.; Smith, E. J.; Phillips, J. L. +1 more
On day 92:109, at about 5.4 AU and 9° south, Ulysses detected a strong quasi-parallel shock wave leading an interaction region. We describe this singular event on different temporal scales, placing emphasis on the magnetic field observations. The solar wind preceding the shock presented very unusual long-lived conditions: for about one day the int…
First catalogue of stars with the photoelectric astrolabe in San Juan.
Wang, Z.; Zhao, G.; Lu, L. +9 more
On the basis of data observed in San Juan of Argentina with the photoelectric astrolabe mark II (PA II) of Beijing Astronomical Observatory from 23 Feb., 1992 to 28 Feb., 1995, residuals of 7200 stars are reduced from about 230000 observations of stars. The mean precision of the residuals is +/-0.046". Using the data, the first catalogue of stars …
Wave field analysis by magnetic measurements at satellite arrays: generalized minimum variance analysis
Glassmeier, K. H.; Motschmann, U.; Southwood, D. J. +1 more
The main goal of the CLUSTER mission with four identical spacecraft is the spatial resolution of plasma structures. For the determination of the wave vectors of a wave field from four positions classical Fourier analysis is inappropriate. We develop a generalized minimum variance technique which gives a high wave vector resolution though the spati…
Helioradius Dependence of Interplanetary Carbon and Oxygen Abundances during 1991 Solar Activity
Krimigis, S. M.; Lanzerotti, L. J.; Maclennan, C. G. +3 more
A comparison of the heliocentric dependence of the relative abundance of low energy (~1 MeV nucleon-1) carbon and oxygen on the Ulysses (~3--4 AU) and Voyager 1 and 2 (~35 and ~47 AU) spacecraft shows that the C/O abundance ratio is significantly smaller at the larger radial distances. This finding is attributed to a more abundant seed population …
Further optical and UV spectroscopy of stars in the direction of the Riegel & Crutcher cold cloud
Hambly, N. C.; Bates, B.; Kemp, S. N.
Further optical and UV spectral data are presented for four stars in the direction of the Riegel & Crutcher cold cloud. Two of the stars lie close in position to the area covered by our previous optical, UV and radio studies near l=10 deg, while the other two stars lie near l=15 deg. The stars range in distance from about 140 pc to 1.5 kpc. Th…
Starburst activity in X-ray and FIR luminous galaxies: the case of NGC 4619 and IRAS 15564+6359.
Mas-Hesse, J. M.; Rodriguez-Pascual, P. M.; Cerviño, M. +1 more
We have analyzed the multiwavelength (soft X-rays to far infrared) energy distribution of IRAS 15564+6359 and NGC 4619, two galaxies previously not classified as active galaxies but found during the ROSAT All Sky Survey to be very luminous in the X-ray and far infrared (FIR) ranges. By comparison with population synthesis evolutionary models we ha…
The Heliospheric Magnetic Field
Balogh, André
The heliospheric magnetic field (HMF) is an important component of the heliospheric medium. It has been the subject of extensive studies for the past thirty five years. There is a very large observational data base, mostly from the vantage point of the ecliptic plane, but now also from the solar polar regions, from the Ulysses mission. This review…