Search Publications
Relationship between wave processes in sunspots and quasi-periodic pulsations in active region flares
Nakariakov, V. M.; Sych, R.; Karlicky, M. +1 more
A phenomenological relationship between oscillations in a sunspot and quasi-periodic pulsations (QPP) in flaring energy releases at an active region (AR) above the sunspot is established. The analysis of the microwave emission recorded by the Nobeyama Radioheliograph at 17 GHz shows a gradual increase in the power of the 3-min oscillation train in…
The second INTEGRAL AGN catalogue
Mas-Hesse, J. M.; Gehrels, N.; Ricci, C. +7 more
Aims: The INTEGRAL mission provides a large data set for studying the hard X-ray properties of AGN and allows testing of the unified scheme for AGN.
Methods: We present analysis of INTEGRAL IBIS/ISGRI, JEM-X, and OMC data for 199 AGN supposedly detected by INTEGRAL above 20 keV.
Results: The data analysed here allow significant spectral ex…
Multi-wavelength study of XMMU J2235.3-2557: the most massive galaxy cluster at z > 1
Böhringer, H.; Demarco, R.; Lidman, C. +14 more
Context: The galaxy cluster XMMU J2235.3-2557 (hereafter XMM2235), spectroscopically confirmed at z = 1.39, is one of the most distant X-ray selected galaxy clusters. It has been at the center of a multi-wavelength observing campaign with ground and space facilities.
Aims: We characterize the galaxy populations of passive members, the thermody…
Chemical enrichment in the cluster of galaxies Hydra A
Finoguenov, A.; Böhringer, H.; Simionescu, A. +4 more
We analyzed global properties, radial profiles, and 2D maps of the metal abundances and temperature in the cool core cluster of galaxies Hydra A using a deep ~120 ks XMM-Newton exposure. The best fit among the available spectral models is provided by a Gaussian distribution of the emission measure (gdem). We can accurately determine abundances for…
Analysis of Galactic late-type O dwarfs: more constraints on the weak wind problem
Bouret, J. -C.; Martins, F.; Hillier, D. J. +3 more
Aims: We investigate the stellar and wind properties of a sample of late-type O dwarfs. Previous analyses of such stars have found very low mass-loss rates; rates much lower than predicted by theory (the weak wind problem).
Methods: Far-UV to optical spectra of five Galactic O stars were analyzed: HD 216898 (O9IV/O8.5V), HD 326329 (O9V), HD 66…
Revealing the magnetic field in a distant galaxy cluster: discovery of the complex radio emission from MACS J0717.5 +3745
Gentile, G.; Bonafede, A.; Govoni, F. +7 more
Aims: To study at multiple frequencies the radio emission arising from the massive galaxy cluster MACS J0717.5+3745 (z=0.55). Known to be an extremely complex cluster merger, the system is uniquely suited for an investigation of the phenomena at work in the intra-cluster medium (ICM) during cluster collisions.
Methods: We use multi-frequency a…
INPOP08, a 4-D planetary ephemeris: from asteroid and time-scale computations to ESA Mars Express and Venus Express contributions
Laskar, J.; Fienga, A.; Le Poncin-Lafitte, C. +6 more
The latest version of the planetary ephemerides developed at the Paris Observatory and at the Besançon Observatory is presented. INPOP08 is a 4-dimension ephemeris since it provides positions and velocities of planets and the relation between Terrestrial Time and Barycentric Dynamical Time. Investigations to improve the modeling of asteroids are d…
Parameters of Herbig Ae/Be and Vega-type stars
Eiroa, C.; Montesinos, B.; Mora, A. +1 more
Context: This work presents the characterization of 27 young early-type stars, most of them in the age range 1-10 Myr, and three suspected hot companions of post-T Tauri stars belonging to the Lindroos binary sample. Most of these objects show IR excesses in their spectral energy distributions, which are indicative of the presence of disks. The wo…
The dust condensation sequence in red supergiant stars
Eriksson, K.; Hony, S.; Decin, L. +3 more
Context: Red supergiant (RSG) stars exhibit significant mass loss by means of a slow, dense wind. They are often considered to be the more massive counterparts of Asymptotic Giant Branch (AGB) stars. While AGB mass loss is related to their strong pulsations, the RSG are often only weakly variable. This raises the question of whether their wind-dri…
The redshift and afterglow of the extremely energetic gamma-ray burst GRB 080916C
Cenko, S. B.; Greiner, J.; Berger, E. +22 more
Context: The detection of GeV photons from gamma-ray bursts (GRBs) has important consequences for the interpretation and modelling of these most-energetic cosmological explosions. The full exploitation of the high-energy measurements relies, however, on accurate knowledge of the distance to the events.
Aims: Here we report on the discovery of …