[en] One of the main limitations to the sensitivity of the infrared camera ISOCAM on-board the Infrared Space Observatory (ISO) comes from responsivity variations and glitches caused by the impacts of charged particles in photo-detectors. An international glitch working group has been created in order to centralize information about these phenomena and prepare for future space experiments. Results about ISOCAM glitches are presented here. The predicted glitch rate has been re-evaluated and compared to in-flight measurements. The study of temporal and spatial properties of glitches has led to a classification into 3 distinct families. These families are related to the linear energy transfer (LET) of charged particles interacting with the detectors

[en] SVOM (Space-based multi-band astronomical Variable Objects Monitor) has been designed to detect all known types of gamma-ray bursts (GRBs), to provide fast and reliable GRB positions, to measure the broadband spectral shape and temporal properties of the GRB prompt emission, and to quickly identify the optical afterglows, including those which are highly redshifted. In this paper, we focus on the alert distribution network and the public data which will be available to the GRB community

[en] We present a grid of values for the moment of inertia and the potential energy of hydrogen-burning stars as derived from evolutionary models computed with updated input physics and opacities. A range from 1.0 to 25 solar masses is covered using a standard chemical composition (X, Z) = (0.70, 0.02) together with a value of 2.0 for the mixing-length ratio. Values of the gyration radius and the potential energy of each individual configuration are tabulated in a format suitable for the use in dynamical studies of binary stars. A comparison with previous computations, which adopted very simplified structures, as well as variations with respect to mass, age and chemical composition, are discussed in some detail

[en] Extensive stellar evolution calculations are presented with the main object of improving and extending the comparison of empirical stellar data in general with theoretical predictions based on standard but updated physics and, in particular, absolute dimensions derived from the analysis of double-lined eclipsing binaries. Computations were made for five chemical compositions around the Ross-Aller mixture and the most recent opacities from Los Alamos library was used

[en] A new grid of evolutionary stellar models with core overshooting and mass loss is presented. In addition to these two physical mechanisms, new opacity Tables from Los Alamos Opacity Library were used, the chemical composition was adopted to be (X, Z) = (0.70, 0.02) and the mixing-length parameter was fixed to 2.0. The computed evolutionary tracks cover the mass range from 1.12 up to 25 solar mass. Models with about 300 layers inside the stellar configuration were calculated from the zero-age main sequence until the ignition of helium in the core. The first three harmonics of the stellar internal structure (k₂, k₃ and k₄) needed for apsidal motion studies in close binaries are given for the first time in this kind of models. The new physical mechanisms introduced are found to be responsible for structures significantly more centrally concentrated in mass than previous models. Differences are estimated in around 0.10, in log k₂, for a typical case

[en] We present the SVOM (Space-based multi-band astronomical Variable Object Monitor) mission, that is being developed in cooperation between the Chinese National Space Agency (CNSA), the Chinese Academy of Science (CAS) and the French Space Agency (CNES), and is expected to be launched in 2013. Its scientific objectives include the study of the GRB phenomenon (diversity and unity), GRB physics (particle acceleration, radiation mechanisms), GRB progenitors, cosmology (host galaxies, intervening medium, star formation history, re-ionization, cosmological parameters), and fundamental physics (origin of cosmic rays, Lorentz invariance, gravitational waves sources). SVOM is designed to detect all known types of Gamma-Ray Bursts (GRBs), to provide fast and reliable GRB positions, to measure the broadband spectral characteristics and temporal properties of the GRB prompt emission. This will be obtained in first place thanks to a set of four space flown instruments. A wide field (similar to 2 sr) coded mask telescope (ECLAIRs), operating in the 4-250 keV energy range, will provide the triggers and localizations, while a gamma-ray non-imaging spectrometer (GRM), sensitive in the 50 keV-5 MeV domain, will extend the prompt emission energy coverage. After a satellite slew, in order to place the GRB direction within field of view of the two narrow field instruments - a soft X-ray (XIAO), and a visible telescope (VT) - the GRB position will be refined and the study of the early phases of the GRB afterglow will be possible. A set of three ground based dedicated instruments, two robotic telescopes (GFTs) and a wide angle optical monitor (GWAC), will complement the space borne instruments. Thanks to the low energy trigger threshold (similar to 4 keV) of the ECLAIRs, SVOM is ideally suited for the detection of soft, hence potentially most distant, GRBs. Its observing strategy is optimized to facilitate follow-up observations from the largest ground based facilities. (authors)

[en] We determine the absolute dimensions of the eclipsing binary V578 Mon, a detached system of two early B-type stars (B0V + B1V, P = 2.40848 days) in the star-forming region NGC 2244 of the Rosette Nebula. From the light curve analysis of 40 yr of photometry and the analysis of HERMES spectra, we find radii of 5.41 ± 0.04 R_☉ and 4.29 ± 0.05 R_☉, and temperatures of 30,000 ± 500 K and 25,750 ± 435 K, respectively. We find that our disentangled component spectra for V578 Mon agree well with previous spectral disentangling from the literature. We also reconfirm the previous spectroscopic orbit of V578 Mon finding that masses of 14.54 ± 0.08 M_☉ and 10.29 ± 0.06 M_☉ are fully compatible with the new analysis. We compare the absolute dimensions to the rotating models of the Geneva and Utrecht groups and the models of the Granada group. We find that all three sets of models marginally reproduce the absolute dimensions of both stars with a common age within the uncertainty for gravity-effective temperature isochrones. However, there are some apparent age discrepancies for the corresponding mass-radius isochrones. Models with larger convective overshoot, >0.35, worked best. Combined with our previously determined apsidal motion of 0.07089_−0.00013^+0.00021 deg cycle^–1, we compute the internal structure constants (tidal Love number) for the Newtonian and general relativistic contribution to the apsidal motion as log k ₂ = –1.975 ± 0.017 and log k ₂ = –3.412 ± 0.018, respectively. We find the relativistic contribution to the apsidal motion to be small, <4%. We find that the prediction of log k _2,theo = –2.005 ± 0.025 of the Granada models fully agrees with our observed log k ₂.

[en] The payload of INTEGRAL, the space gamma-ray observatory launched in October 2002, features two gamma-ray telescopes that take advantage of the semiconductor technologies. The spectrometer SPI, is equipped with 19 high-purity germanium detectors cooled at 85 K. We will report on the SPI in-flight background, performance, the detector evolution and the annealings performed every 6 months. The INTEGRAL Soft Gamma-Ray Imager (ISGRI) is the low-energy camera of the IBIS telescope. It is the first large camera equipped with CdTe detectors. We will present some system aspects, in particular the noisy pixel handling and will report on its in-flight background, performance and their evolution