Search Publications

Radar detection of subsurface features on Mars

Orosei, R.; Kartashov, D. V.; Shchuko, O. B.

The structure of the pulse radar signal reflected from continuously changing layered Martian crust is investigated theoretically. As a simple model of stratigraphy, we considered one layer with electrodynamics' parameters increasing or decreasing exponentially upon a depth laying on monolith base and covered by homogeneous layer. This exponential …

The central region of NGC 3077: ground-based photometry and age of bright `starlike' objects

Karachentsev, I. D.; Makarova, L. N.; Notni, P.

We present UBVI_C photometry of starlike objects in the central region of NGC 3077. The colour-colour and colour-magnitude diagrams of the objects are discussed. Many of the objects under consideration, starlike from the ground, are probably dense young star clusters (super star clusters, SSC). Ages spreading over ∼4 to ∼150 Myr are estimated for …

Multiple Flux Rope Events at the High-Latitude Magnetopause on January 26, 2001: Current Density Calculation

Glassmeier, K. -H.; Shen, Chao; Cao, Jin-Bin +12 more

A systematic comparison is carried out for three methods of current density calculation based on simultaneous magnetic field measurements of four-spacecraft Cluster mission. It is demonstrated analytically and numerically that within the linear approximation, all these methods lead to exactly the same results. As a case study, the current density …

The close binary system SU Ind

Budding, E.; Zeilik, M.; Rhodes, M. +1 more

Photometric data on the southern mid-F type close eclipsing binary system SU Ind from the Carter Observatory (NZ) were examined, together with a light curve obtained from the Hipparcos Epoch Photometry (HEP) database. The system appears detached, although appreciably evolved from the Zero Age Main Sequence. The HEP period must be accurate for its …

Dependence of frequency of nonlinear cold plasma cylindrical oscillations on electron density

Fainberg, J.; Osherovich, Vladimir

For cold plasma, the frequency of small amplitude Langmuir oscillations along one Cartesian coordinate is ω_po=√4πe²n_o/m_e , where n_p=n_o is the constant proton density which is equal to the average electron density n_e¯. This formula for ω_po is the basis for measu…

High Spatial Resolution Hubble Space Telescope NICMOS Observations of Markarian 231

Schneider, G.; Neugebauer, G.; Low, F. J.

Observations of Markarian 231 at 1.1 µm taken with NICMOS on the Hubble Space Telescope are described. The brightness of the object in the near-infrared, and the inherent short-term stability of the NICMOS optical and instrumental system, enables the application of special observational and analysis techniques that effectively increase high …

PFS: an effective instrument for the study of martian environment

Grassi, D.; Formisano, V.; Maturilli, A. +2 more

We present here an evaluation of basic PFS sounding capabilities; results refer to the analysis of a single, calibrated spectrum. PFS is an infrared Fourier spectrometer on board of Mars Express mission. It covers the thermal infrared (250-1750 cm ^-1) with a resolution of 1.5 cm ^-1, as well as the near infrared (2000-8200 cm …

Elemental composition and distribution in SNRs: X-ray spectroscopy

Decourchelle, A.

I present a comparative review focusing on three young Supernova Remnants, Cas A, Tycho and Kepler, in the light of recent X-ray observations obtained with the XMM-Newton and Chandra satellites. Recently available, X-ray spectro-imagery of young Supernova Remnants is providing unique information on the interaction region between the ejected materi…

Stellar kinematics in the centers of globular clusters

Gerssen, J.

The high central stellar densities in globular clusters provide a unique environment to study the fundamental dynamical process of two-body relaxation. This process is the main driver of the dynamical evolution in the center of a globular cluster and has a profound effect on the structure of the cluster and on its stellar environment. We have obta…

Erratum: Probable intermediate-mass black holes in NGC 4559: XMM-Newton spectral and timing constraints

Cropper, Mark; Soria, Roberto; Wu, Kinwah +3 more