Search Publications
Oscillations in a solar filament: first observation of long periods in the HeI 584.33 Å line, modelling and diagnostic
Bocchialini, K.; Pouget, G.; Solomon, J.
Three long observations of filaments were carried out in the 584.33 HeI line during MEDOC campaigns in November 2003 and November 2004, by the Coronal Diagnostic Spectrometer onboard SOHO. Their duration was 15-16 h and the temporal resolution was 20 s, allowing measurements of the entire range of periodicities theoretically expected in a filament…
An empirical calibration of sulphur abundance in ionised gaseous nebulae
Kehrig, C.; Pérez-Montero, E.; Vílchez, J. M. +1 more
We have derived an empirical calibration of the abundance of S/H as a function of the S{23} parameter, defined using the bright sulphur lines of [SII] and [SIII]. Contrary to the case for the widely used O{23} parameter, the calibration remains single valued up to the abundance values observed in the disk HII regions. The calibration is based on a…
The XMM large scale structure survey: properties and two-point angular correlations of point-like sources
Maccagni, D.; Chiappetti, L.; Valtchanov, I. +9 more
We analyze X-ray sources detected over 4.2 pseudo-contiguous sq. deg. in the 0.5-2 keV and 2-10 keV bands down to fluxes of 2× 10-15 and 8× 10-15 erg s-1 cm-2 respectively, as part of the XMM-Newton Large Scale Structure Survey. The log N-log S in both bands shows a steep slope at bright fluxes, but agre…
Monitoring atmospheric phenomena on Titan
Drossart, P.; Gendron, E.; Lebonnois, S. +7 more
For the past 8 years (1998-2005), we have used adaptive optics imaging (with VLT/NACO and CFHT/PUEO) to explore Titan's atmosphere, which is currently scrutinized in situ by the Cassini-Huygens mission. In the course of our work, we have found variations, such as as seasonal and diurnal effects, as well as temporary features in the southern polar …
The X-ray spectrum of the bursting atoll source 4U 1728-34 observed with INTEGRAL
Götz, D.; Goldoni, P.; Mereghetti, S. +5 more
We present for the first time a study of the 3-200 keV broad band spectra of the bursting atoll source 4U 1728-34 (GX 354-0) along its hardness intensity diagram. The analysis was done using the INTEGRAL public and Galactic Center deep exposure data ranging from February 2003 to October 2004. The spectra are well described by a thermal Comptonizat…
Dynamical and chemical evolution of NGC 1569
Matteucci, F.; Recchi, S.; Hensler, G. +1 more
Blue Compact Dwarf and Dwarf Irregular galaxies are generally believed to be unevolved objects, due to their blue colors, compact appearance and large gas fractions. Many of these objects show an ongoing intense burst of star formation or have experienced it in the recent past. By means of 2-D hydrodynamical simulations, coupled with detailed chem…
Dwarf novae in the Hamburg quasar survey: rarer than expected
Gänsicke, B. T.; Hagen, H. -J.; Engels, D. +12 more
Aims.We report the discovery of five new dwarf novae that were spectroscopically identified in the Hamburg Quasar Survey (HQS), and discuss the properties of the sample of new dwarf novae from the HQS.
Methods.Follow-up time-resolved spectroscopy and photometry have been obtained to characterise the new systems.
Results.The orbital periods d…
The role of the LIRG and ULIRG phases in the evolution of Ks-selected galaxies
Le Floc'h, E.; Dole, H.; Lagache, G. +5 more
Aims.We investigate the role of the luminous infrared galaxy (LIRG) and ultra-luminous infrared galaxy (ULIRG) phases in the evolution of K_s-selected galaxies and, in particular, Extremely Red Galaxies (ERGs).
Methods: .With this aim, we compare the properties of a sample of 2905 K_s<21.5 (Vega mag) galaxies in the GOODS/CDFS with the sub-…
SS 433: a phenomenon imitating a Wolf-Rayet star
Ábrahám, P.; Fuchs, Y.; Koch Miramond, L.
We present mid-infrared (2-12 µm) spectra of the microquasar SS 433 obtained with the Infrared Space Observatory (spectroscopic mode of ISOPHOT and ISOCAM). We compare them to the spectra of four Wolf-Rayet stars: WR 78, WR 134, WR 136, and WR 147 in the same wavelength range. The mid-infrared spectrum of SS 433 mainly shows ion{H}{i} and io…
An XMM-Newton survey of the Local Group galaxy M 33 - variability of the detected sources
Pietsch, W.; Haberl, F.; Hatzidimitriou, D. +3 more
We present an analysis of the individual observations of a deep XMM-Newton survey of the Local Group spiral galaxy M 33. We detected a total of 350 sources with fluxes (in the 0.2-4.5 keV energy band) in the range 6.7 × 10-16-1.5 × 10-11 erg s-1. This comprehensive study considers flux variability, spectral charact…