Search Publications
Imaging extended sources with coded mask telescopes: application to the INTEGRAL IBIS/ISGRI instrument
Terrier, R.; Renaud, M.; Lebrun, F. +4 more
Context: .In coded mask techniques, reconstructed sky images are pseudo-images: they are maps of the correlation between the image recorded on a detector and an array derived from the coded mask pattern.
Aims: .The INTEGRAL /IBIS telescope provides images where the flux of each detected source is given by the height of the local peak in the co…
THEMIS/MSDP magnetic field measurements
Schmieder, B.; Berlicki, A.; Mein, P.
We present an analysis of longitudinal magnetic field measurements using the spectral data obtained with the French - Italian polarisation free telescope THEMIS working in Multichannel Subtractive Double Pass (MSDP) mode. We also used SOHO/MDI data to extend our analysis. THEMIS observations in the MSDP mode allows us to perform imaging spectropol…
Hipparcos astrometric orbits for two brown dwarf companions: HD 38529 and HD 168443
Quirrenbach, A.; Reffert, S.
Context: .HD 38529 and HD 168443 have previously been identified as systems with two substellar companion candidates using precise radial velocity measurements.Aims.We want to further constrain their orbits and the nature of the outer companions.Methods.We fit astrometric orbits of the outer substellar companions in the two systems to the Hipparco…
Optical/near-infrared observations of the black hole candidate XTE J1720-318 : from high-soft to low-hard state
Chaty, S.; Bessolaz, N.
Aims.To gain a better understanding of high-energy Galactic sources, we observed the Galactic X-ray binary and black hole candidate XTE J1720-318 in the optical and near-infrared, just after the onset of its X-ray outburst in January, 2003. These observations were obtained with the ESO/NTT as the Target of Opportunity, in February and April 2003.<…
The intensity contrast of solar photospheric faculae and network elements. II. Evolution over the rising phase of solar cycle 23
Sanahuja, B.; Ortiz, A.; Domingo, V.
We studied the radiative properties of small magnetic elements (active region faculae and the network) during the rising phase of solar cycle 23 from 1996 to 2001, determining their contrasts as a function of heliocentric angle, magnetogram signal, and the solar cycle phase. We combined near-simultaneous full disk images of the line-of-sight magne…
Fe XIX observations of active region brightenings in the corona
Solanki, S. K.; Innes, D. E.; Wang, T. J.
Small flarelike brightenings seen in the hot flare line, Fe XIX, by the spectrometer SUMER on SOHO are analysed. We observe active region coronae about 30 Mm off the limb of the Sun for a period of several days. Brightenings are observed with a frequency 3-14 per hour and their lifetimes range from 5-150 min, with an average of about 25 min. The m…
Automatic classification of eclipsing binaries light curves using neural networks
Sarro, L. M.; Sánchez-Fernández, C.; Giménez, Á.
In this work we present a system for the automatic classification of the light curves of eclipsing binaries. This system is based on a classification scheme that aims to separate eclipsing binary systems according to their geometrical configuration in a modified version of the traditional classification scheme. The classification is performed by a…
An X-ray bright ERO hosting a type 2 QSO
Page, M. J.; Akiyama, M.; Carrera, F. J. +8 more
We present the XMM-Newton and the optical-VLT spectra along with the optical and the near-infrared photometric data of one of the brightest X-ray (F2{-10 keV}∼10-13 erg s-1 cm-2) extremely red objects (R-K≥5) discovered so far. The source, XBS J0216-0435, belongs to the XMM-Newton Bright Serendipitous Su…
Diffuse light and building history of the galaxy cluster Abell 2667
Kneib, J. -P.; Adami, C.; Slezak, E. +3 more
Aims.We searched for diffuse intracluster light in the galaxy cluster Abell 2667 (z=0.233) from HST images in three broad band-filters.
Methods: .We applied an iterative multi-scale wavelet analysis and reconstruction technique to these images, which allows to subtract stars and galaxies from the original images.
Results: .We detect a zone…
Coma revealed as an extended hard X-rays source by INTEGRAL IBIS/ISGRI
Terrier, R.; Bélanger, G.; Renaud, M. +2 more
Aims.We report the INTEGRAL/IBISobservations of the Coma Clusterin the hard X-ray/soft γ-raydomain.
Methods: .Since the Coma Clusterappears as an extended source, its global intensity and significance cannot be directly extracted with standard coded mask analysis. We used the method of imaging the extended sources with a coded mask telescope d…