Search Publications
Discovery of a bright X-ray transient in the Galactic Center with XMM-Newton
Burwitz, V.; Grosso, N.; Warwick, R. S. +4 more
We report the discovery of a bright X-ray transient object,
Kinematics of RHB stars to trace the structure of the Galaxy
de Boer, K. S.; Altmann, M.; Kaempf, T. A.
Red horizontal-branch (RHB) stars have been selected from the Hipparcos catalogue to investigate their kinematics and spatial distribution. Hipparcos parallaxes, literature radial velocities and Hipparcos proper motions, together with models for the gravitational potential of the Milky Way allow a calculation of the actual velocity vectors and the…
Kinematic and chemical evolution of early-type galaxies
Böhm, A.; Thomas, D.; Bender, R. +3 more
We investigate in detail 13 early-type field galaxies with 0.2<z<0.7 drawn from the Fors Deep Field. Since the majority (9 galaxies) is at z≈0.4, we compare the field galaxies to 22 members of three rich clusters with z=0.37 to explore possible variations caused by environmental effects. We exploit VLT/FORS spectra (R≈1200) and HST/ACS imagi…
The ionization structure of early-B supergiant winds
Massa, D.; Prinja, R. K.; Searle, S. C.
We present empirically determined ionization conditions for the winds of 106 luminous B0 to B5 stars observed by IUE. The UV wind lines are modelled to extract products of mass-loss rates times ionization fractions (\mdot qi(w) where w = v/v∞) for N V, C IV, Si IV, Si III, Al III and C II. We describe the general behaviour of…
Discovery of the INTEGRAL X/γ-ray transient IGR J00291+5934: A Comptonised accreting ms pulsar?
Rodriguez, J.; Walter, R.; Eckert, D. +8 more
We report the discovery of a high-energy transient with the IBIS/ISGRI detector on board the INTEGRAL observatory. The source, namely
XMM-Newton observations of two transient millisecond X-ray pulsars in quiescence
Campana, S.; Stella, L.; Israel, G. L. +1 more
We report on XMM-Newton observations of two X-ray transient millisecond pulsars (XRTMSPs). We detected XTE J0929-314 with an unabsorbed luminosity of ∼ 7× 1031 erg s-1 (0.5-10 keV) at a fiducial distance of 10 kpc. The quiescent spectrum is consistent with a simple power law spectrum. The upper limit on the flux from a coolin…
The late merging phase of a galaxy cluster: XMM EPIC observations of A 3266
Pratt, G. W.; Belsole, E.; Sauvageot, J. L.
We present a mosaic of five XMM-Newton observations of the nearby (z=0.0594) merging galaxy cluster Abell 3266. We use the spectro-imaging capabilities of XMM-Newton to build precise (projected) temperature, entropy, pressure and Fe abundance maps. The temperature map exhibits a curved, large-scale hot region, associated with elevated entropy leve…
XMM-Newton spectral properties of the ultraluminous IRAS galaxy Mrk 273
Lutz, D.; Balestra, I.; Boller, Th. +2 more
We present a 23 ks XMM-Newton observation of the Ultraluminous Infrared Galaxy (ULIRG) Mrk 273. The hard X-ray spectrum can be modeled by a highly absorbed (~7×1023 cm-2) power law plus an Fe Kα emission line. The iron line (detected at more than 99% c.l.) is broad (σ=0.26+0.37-0.17 keV), suggesting poss…
XMM-Newton observations of AM CVn binaries
Cropper, M.; Ramsay, G.; Hakala, P. +3 more
We present the results of XMM-Newton observations of four AM CVn systems - AM CVn, CR Boo, HP Lib and GP Com. Their light curves show very different characteristics. The X-ray light curves show no coherent pulsations, suggesting the accreting white dwarfs have relatively low magnetic field strengths. Their spectra were best modelled using a multi-…
A mapping of martian water sublimation during early northern summer using OMEGA/Mars Express
Bibring, J. -P.; Gondet, B.; Langevin, Y. +8 more
The OMEGA imaging spectrometer aboard Mars Express has been used to map the water vapor abundance over the martian surface, from the analysis of the 2.6 µm band of H2O. As a preliminary result of this study, we present water vapor maps in the northern hemisphere at the time of the northern polar cap sublimation (Ls = 94-112 deg). The maps sh…