Search Publications
Circumstellar dust shells of hot post-AGB stars
Parthasarathy, M.; Gauba, G.
Parameters of the circumstellar dust shells of 15 hot post-AGB stars have been derived using a radiative transfer code (DUSTY). Combining the optical, near and far-infrared (ISO, IRAS) data of the stars, we have reconstructed their spectral energy distributions (SEDs) and estimated the dust temperatures, mass loss rates, angular radii of the inner…
Solar cycle dependence of the helium focusing cone from SOHO/UVCS observations. Electron impact rates and associated pickup ions
Bertaux, J. -L.; Raymond, J. C.; Uzzo, M. +5 more
The Ultraviolet Coronograph on board SOHO (UVCS) has observed the 58.4 nm glow of the interplanetary He focusing cone at regular intervals since 1996. The intensity decrease with time already observed during the first two years (Michels et al. \cite{michels}) has dramatically amplified during the solar activity increase. Intensities seem to reach …
On the Wolf-Rayet counterpart to IC 10 X-1
Crowther, P. A.; Clark, J. S.
Recent CHANDRA observations of the starburst galaxy
Spectral evolution of weak bursts from SGR 1806-20 observed with INTEGRAL
Hurley, K.; Götz, D.; Mereghetti, S. +1 more
We report on bursts from the Soft Gamma-Ray Repeater SGR 1806-20 detected with INTEGRAL in October 2003, during a period of moderate activity of the source. The spectral and temporal properties of 21 short bursts are consistent with those found in previous observations, even if these bursts are among the faintest observed in the 15-200 keV range f…
Studies of orbital parameters and pulse profile of the accreting millisecond pulsar XTE J1807-294
Freyberg, M. J.; Kendziorra, E.; Smith, M. J. S. +4 more
The accreting millisecond pulsar XTE J1807-294 was observed as a Target of Opportunity (ToO) by XMM-Newton on March 22, 2003 after its discovery on February 21, 2003 by RXTE. The source was detected in its bright phase with an observed average count rate of 33.3 cts s-1 in the EPIC-pn camera in the 0.5-10 keV energy band (3.7 mCrab). Us…
Dynamical mass estimates for two luminous young stellar clusters in Messier 83
Larsen, S. S.; Richtler, T.
Using new data from the UVES spectrograph on the ESO Very Large Telescope and archive images from the Hubble Space Telescope, we have measured projected velocity dispersions and structural parameters for two bright young star clusters in the nearby spiral galaxy
Visible spectral properties of asteroid 21 Lutetia, target of Rosetta Mission
Barbieri, C.; Lazzarin, M.; Marchi, S. +1 more
Rosetta spacecraft was successfully launched on March 2nd 2004 after its launch postponement in January 2003. Owing to this delay all the original targets, comet and asteroids, have been changed. In particular, on its 10 years journey to the new comet 67P/Churyumov-Gerasimenko, the spacecraft will pass close to the asteroid 21 Lutetia. In this pap…
Determination of the 3D structure of an EUV-filament observed by SoHO/CDS, SoHO/SUMER and VTT/MSDP
Heinzel, P.; Anzer, U.; Schmieder, B. +1 more
Heinzel et al. (\cite{hein1}) found that filaments seem to be much more extended in EUV spectral lines than in Hα. In this paper we reconstruct the 3D structure of the extensions of the EUV-filament observed on 15 October 1999 by SoHO/CDS and SoHO/SUMER. Small Hα structures were observed by VTT/MSDP. We computed the bottom and top heights of the E…
High-energy observations of the state transition of the X-ray nova and black hole candidate XTE J1720-318
Frontera, F.; Goldoni, P.; Parmar, A. N. +13 more
We report the results of extensive high-energy observations of the X-ray transient and black hole candidate XTE J1720-318 performed with INTEGRAL, XMM-Newton and RXTE. The source, which underwent an X-ray outburst in 2003 January, was observed in February in a spectral state dominated by a soft component with a weak high-energy tail. The XMM-Newto…
Polar magnetic flux on the Sun in 1996-2003 from SOHO/MDI data
Benevolenskaya, E. E.
Polarity of the polar magnetic fields on the Sun changes in every 11-year sunspot cycle, affecting the large-scale structure of the corona and heliosphere. Using the SOHO/MDI data, the flux of the radial component of the magnetic field is estimated for different latitudinal zones. It is estimated that the total magnetic flux of the Northern polar …