Search Publications
Test of methods to infer the magnetic reconnection geometry from spacecraft data
Baumjohann, W.; Hesse, M.; Birn, J. +5 more
When analyzing data from a cluster of spacecraft (such as Cluster or MMS) crossing a site of magnetic reconnection, it is desirable to be able to determine the orientation of the reconnection site. If the reconnection is quasi-two dimensional, there are three key directions, the direction of inhomogeneity (direction across the reconnection site), …
Radial Evolution of Solar Wind Turbulence during Earth and Ulysses Alignment of 2007 August
Balogh, A.; Bavassano, B.; Bruno, R. +4 more
At the end of 2007 August, during the minimum of solar cycle 23, a lineup of Earth and Ulysses occurred, giving the opportunity to analyze, for the first time, the same plasma sample at different observation points, namely at 1 and 1.4 AU. In particular, it allowed us to study the radial evolution of solar wind turbulence typical of fast wind stre…
Proper motions and natures of First Byurakan Survey blue stellar objects
Mickaelian, A. M.; Sinamyan, P. K.
A new method for combined calculations of proper motions (PMs) based on accurate measurements of POSS1 and POSS2 epoch plates is given. The positional accuracy of various surveys and catalogues is estimated, and statistical weights for each of them are established. To achieve the best positions, weighted averaging of direct measurements on DSS1/DS…
Multiband photometric decomposition of nuclear stellar disks
Morelli, L.; Dalla Bontà, E.; Corsini, E. M. +4 more
Context. Small, bright stellar disks with scale lengths of a few tens of parsec are known to reside in the center of galaxies. They are believed to have formed in a dissipational process as the end result of star formation in gas either accreted during a merging (or acquisition) event or piled up by the secular evolution of a nuclear bar. Only a f…
New Evidence for a Black Hole in the Compact Binary Cygnus X-3
Titarchuk, Lev; Shaposhnikov, Nikolai; Shrader, Chris R.
The bright and highly variable X-ray and radio source known as Cygnus X-3 was among the first X-ray sources discovered, yet it remains in many ways an enigma. It is known to consist of a massive, Wolf-Rayet primary in an extremely tight orbit with a compact object. However, one of the most basic of parameters—the mass of the compact object—is not …
Predicted gamma-ray line emission from the Cygnus complex
Meynet, G.; Knödlseder, J.; Diehl, R. +1 more
Context. The Cygnus region harbours a huge complex of massive stars at a distance of 1.0-2.0 kpc from us. About 170 O stars are distributed over several OB associations, among which the Cyg OB2 cluster is by far the most important with about 100-120 O stars. These massive stars inject large quantities of radioactive nuclei into the interstellar me…
Comparison between the luminosity functions of X-ray and [OIII] selected AGN
Georgantopoulos, I.; Akylas, A.
We investigate claims according to which the X-ray selection of AGN is not as efficient compared to that based on [OIII] selection because of the effects of X-ray absorption. We construct the predicted X-ray luminosity function both for all Seyferts as well as separately for Seyfert-1 and Seyfert-2 type galaxies, by combining the optical AGN [OIII…
Characterizing Complexity in Solar Magnetogram Data Using a Wavelet-based Segmentation Method
Gallagher, P. T.; McAteer, R. T. J.; Conlon, P. A. +4 more
The multifractal nature of solar photospheric magnetic structures is studied using the two-dimensional wavelet transform modulus maxima (WTMM) method. This relies on computing partition functions from the wavelet transform skeleton defined by the WTMM method. This skeleton provides an adaptive space-scale partition of the fractal distribution unde…
The interface between the stellar wind and interstellar medium around R Cassiopeiae revealed by far-infrared imaging
Izumiura, H.; Stencel, R. E.; Matsunaga, N. +11 more
Aims: The circumstellar dust shells of intermediate initial-mass (~1 to 8 M⊙) evolved stars are generated by copious mass loss during the asymptotic giant branch phase. The density structure of their circumstellar shell is the direct evidence of mass loss processes, from which we can investigate the nature of mass loss.
Method…
Rhea’s gravitational field and interior structure inferred from archival data files of the 2005 Cassini flyby
Anderson, John D.; Schubert, Gerald
There are three published gravitational fields for Rhea, and they all differ significantly. All three published fields fit the data equally well, although not to the noise level. There are obvious trends in the Doppler residuals. However, by restricting the data in the fit to a shorter interval surrounding the closest approach to Rhea, an unbiased…