Search Publications
Variable iron-line emission near the black hole of Markarian 766
Nandra, K.; Turner, T. J.; Porquet, D. +4 more
Aims.We investigate the link between ionised Fe X-ray line emission and continuum emission in a bright nearby AGN, Mrk 766.
Methods: .A new long (433 ks) XMM-Newton observation is analysed, together with archival data from 2000 and 2001. The contribution from ionised line emission is measured and its time variations on short (5-20 ks) timesca…
Study of a transient siphon flow in a cold loop
Doyle, J. G.; Madjarska, M. S.; Bradshaw, S. J. +2 more
Context: .The nature of loops is still a matter of debate with several explanations having been put forward. Simultaneous spectral and imaging data have the capacity to provide a new insight into mass motions, dynamics and energetics of loops.
Aims: .We report on spectral data taken with the Solar Ultraviolet Measurements of Emitted Radiation …
Searches for diffuse X-ray emission around millisecond pulsars: an X-ray nebula associated with PSR J2124-3358
Hui, C. Y.; Becker, W.
We report on diffuse X-ray emission associated with the nearby solitary millisecond pulsar PSR J2124-3358 detected with XMM-Newton and Chandra. The emission extends from the pulsar to the northwest by ~ 0.5 arcmin. The spectrum of the nebular emission can be modeled with a power-law of photon index 2.2±0.4, in line with the emission originating fr…
Properties of X-ray rich gamma ray bursts and X-ray flashes detected with BeppoSAX and Hete-2
Piro, L.; Rossi, E. M.; D'Alessio, V.
We study the spectrum of the prompt emission and the X-ray and optical afterglow fluxes of 54 X-Ray Rich Gamma Ray Burst (XRRs) and X-Ray Flashes (XRFs), observed by BeppoSAX and HETE-2. A comparison is then performed with classical Gamma Ray Bursts (GRBs). The goal of this paper is to investigate the nature of XRRs/XRFs, as high redshift GRBs or …
The star formation history of luminous infrared galaxies
Elbaz, D.; Cesarsky, C.; Charlot, S. +5 more
Aims.We constrain the past star formation histories of a sample of 25 distant (bar{z}∼ 0.7) luminous infrared galaxies (LIRGs) detected with the mid infrared cameras ISOCAM and MIPS onboard the ISO and Spitzer satellites.
Methods: .We used high-resolution VLT-FORS2 spectroscopy in addition to a comprehensive library of 200 000 model optical sp…
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…