Search Publications

A decade of X-ray astronomy with XMM-Newton. Commentary on: Jansen F., Lumb D., Altieri B., et al., 2001, A&A, 365, L1; Strüder L., Briel U., Dennerl K., et al., 2001, A&A, 365, L18; Turner M. J. L., Abbey A., Arnaud M., et al., 2001, A&A, 365, L27

Güdel, M.

Low-amplitude variations detected by CoRoT in the late type Be star HD 175869

Garrido, R.; Frémat, Y.; Neiner, C. +14 more

We present the analysis of the CoRoT data of the B8IIIe star HD 175869 observed during a short run (27.3 days). The light curve shows low-amplitude variations of the order of 0.3 mmag. A frequency within the range determined for the rotational frequency and its 5 harmonics are detected. Other significant frequencies with a low amplitude of a few p…

The Speed Distributions of CMEs after the Projection Correction

Li, K. J.; Gao, P. X.

Observations of coronal mass ejections (CMEs) with coronagraphs are subject to the projection effect, which results in statistical errors in many properties of CMEs, such as the speed. In this paper, using the method based on the cone model to correct the speeds of CMEs due to the projection effect, we study the speed distribution of CMEs before a…

Cosmic Ray Observations in the 3-D Heliosphere through the Solar Cycle: New Insights from Ulysses

Wenzel, Klaus-Peter

Probing the Cosmic Filaments by Means of X-Ray Observations

Hudaverdi, M.; Ercan, E. N.; Bozkurt, M.

Recent observations and numerical simulations show that galaxies are not distributed in the Universe randomly. They are placed like the pearls of a necklace. The matter is spread into the space in the form of cosmic filaments and voids. The intersection regions of these cosmic filaments are what we observe as "clusters of galaxies". In this work w…

Physical parameters of the semiregular variable red giant 2 Cen

Arkharov, A. A.; Ruban, E. V.; Hagen-Thorn, E. I. +1 more

This is a study of photometric data from the Hipparcos catalog and spectrophotometric observations by a group of Pulkovo observers in Bolivia of the variable star 2 Cen (V806 Cen). Fourier analysis yields a more precise value of 12.57 d for the period of the brightness variation instead of 12.0 d. Light curves constructed from the photometric data…

INTEGRAL and Swift/XRT observations of IGR J16460+0849

Zhang, S.; Chen, Y. P.; Li, T. P. +2 more

Aims: IGR J16460+0849 is reported in the 3rd IBIS catalog with the shortest exposure of about 11 ks among all the detected sources, which makes it the most interesting target to be investigated with a deeper exposure. The currently available data have increased to an exposure time of a few hundred ks. This stimulates us to investigate the source a…

Cluster observations showing the indication of the formation of a modified-two-stream instability in the geomagnetic tail

Daly, P. W.; Erkaev, N. V.; Lui, A. T. Y. +4 more

This study presents several observations of the Cluster spacecraft on September 24, 2003 around 15:10 UT, which show necessary prerequisites and consequences for the formation of the so-called modified-two-stream instability (MTSI). Theoretical studies suggest that the plasma is MTSI unstable if (1) a relative drift of electrons and ions is presen…

Planetary Fourier Spectrometer observation of CO₂ (628) isotopologue on Mars

Formisano, Vittorio; Geminale, Anna

Recently, a new CO₂ (628) band around 2982 cm^-1 has been identified by SPICAV SOIR (on board Venus Express mission) at Venus and by ground-based observations at Mars. The Planetary Fourier Spectrometer presently orbiting Mars on board the European Space Agency mission Mars Express has been observing this band since 2004, when…

Magnetic reconnection in space plasma

Retinò, Alessandro; Vaivads, Andris; André, Mats

The terrestrial magnetosphere is a natural laboratory where many important plasma processes can be studied in detail by using high-quality spacecraft measurements of electromagnetic fields and particle distribution functions over a broad range of spatial and temporal scales. One such important process is magnetic reconnection. We discuss recent re…