Search Publications
Power Spectra of Black Holes and Neutron Stars as a Probe of Hydrodynamic Structure of the Source: Diffusion Theory and Its Application to Cygnus X-1 and Cygnus X-2 X-Ray Observations
Titarchuk, Lev; Shaposhnikov, Nikolai; Arefiev, Vadim
We present a model of Fourier power density spectrum (PDS) formation in accretion-powered X-ray binary systems derived from diffusion theory. Timing properties of X-ray emission are considered a result of diffusive propagation of the driving perturbations in a bounded medium. We prove that the integrated power Px of the resulting PDS is…
The Composition of the Solar Wind in Polar Coronal Holes
Gloeckler, George; Geiss, Johannes
The solar wind charge state and elemental compositions have been measured with the Solar Wind Ion Composition Spectrometers (SWICS) on Ulysses and ACE for a combined period of about 25 years. This most extensive data set includes all varieties of solar wind flows and extends over more than one solar cycle. With SWICS the abundances of all charge s…
DISR imaging and the geometry of the descent of the Huygens probe within Titan's atmosphere
Karkoschka, Erich; Schröder, Stefan E.; Tomasko, Martin G. +4 more
The Descent Imager/Spectral Radiometer (DISR) provided 376 images during the descent to Titan and 224 images after landing. Images of the surface had scales between 150 m/pixel and 0.4 mm/pixel, all of which we assembled into a mosaic. The analysis of the surface and haze features in these images and of other data gave tight constraints on the geo…
Long term photometric monitoring with the Mercator telescope. Frequencies and mode identification of variable O-B stars
Dupret, M. -A.; Uytterhoeven, K.; Drummond, R. +37 more
Aims: We selected a large sample of O-B stars that were considered as (candidate) slowly pulsating B, β Cep, and Maia stars after the analysis of their hipparcos data. We analysed our new seven passband geneva data collected for these stars during the first three years of scientific operations of the mercator telescope. We performed a frequency an…
Mobility and topographic effects for large Valles Marineris landslides on Mars
Mangeney, A.; Lucas, A.
Recent experiments on dry granular flows over horizontal plane bare some similarities with large Martian landslides observed in Valles Marineris (VM). However, Martian normalized runout are twice as large as those that observed in dry granular flow experiments. Numerical simulations on theoretical 2D and real 3D topographies reconstructed from rem…
CME Propagation Characteristics from Radio Observations
van Driel-Gesztelyi, L.; Culhane, J. L.; Elliott, H. A. +2 more
We explore the relationship among three coronal mass ejections (CMEs), observed on 28 October 2003, 7 November 2004, and 20 January 2005, the type II burst-associated shock waves in the corona and solar wind, as well as the arrival of their related shock waves and magnetic clouds at 1 AU. Using six different coronal/interplanetary density models, …
Type Ia and II Supernovae Contributions to Metal Enrichment in the Intracluster Medium Observed with Suzaku
Ishida, Manabu; Sato, Kosuke; Ohashi, Takaya +4 more
We studied the properties of the intracluster medium (ICM) in two clusters of galaxies (AWM 7 and Abell 1060) and two groups (HCG 62 and NGC 507) with the X-ray observatory Suzaku. Based on spatially resolved energy spectra, we measured for the first time precise cumulative ICM metal masses within 0.1 and ~0.3r180. Comparing our results…
Multi-Spacecraft Study of the 21 January 2005 ICME. Evidence of Current Sheet Substructure Near the Periphery of a Strongly Expanding, Fast Magnetic Cloud
Dandouras, I.; Fazakerley, A. N.; Crooker, N. U. +6 more
We examine the near-Earth Interplanetary Coronal Mass Ejection (ICME) apparently related to the intense Solar Energetic Particle (SEP) event of 20 January 2005. Our purpose is to contribute to the understanding of the macroscopic structure, evolution and dynamics of the solar corona and heliosphere. Using Cluster, ACE and Wind data in the solar wi…
Photochemical kinetics uncertainties in modeling Titan's atmosphere: First consequences
Dobrijevic, M.; Raulin, F.; Hébrard, E. +1 more
Uncertainties carried by the different kinetic parameters included in photochemical models of planetary atmospheres have rarely been considered even if they are supposed to be contributing mostly to the inconsistencies between observations and computed predictions. In this paper, we report the first detailed analysis of the propagation of uncertai…
Spontaneous axisymmetry breaking of the external magnetic field at Saturn
Goldreich, Peter; Farmer, Alison J.
Saturn's magnetic field is remarkably axisymmetric. Early evidence for nonaxisymmetry came from the periodicity of Saturn's kilometric radio bursts (SKR). Subsequently, percent-level variations of the SKR period were found to occur on timescales of years. A recent breakthrough has been the direct detection of a nonaxisymmetric component of the fie…