Search Publications
Magnetic activity in the photosphere of CoRoT-Exo-2a. Active longitudes and short-term spot cycle in a young Sun-like star
Aigrain, S.; Alonso, R.; Auvergne, M. +18 more
Context: The space experiment CoRoT has recently detected transits by a hot Jupiter across the disc of an active G7V star (CoRoT-Exo-2a) that can be considered as a good proxy for the Sun at an age of approximately 0.5 Gyr.
Aims: We present a spot modelling of the optical variability of the star during 142 days of uninterrupted observations pe…
The zCOSMOS redshift survey: the role of environment and stellar mass in shaping the rise of the morphology-density relation from z ~ 1
Kneib, J. -P.; Maccagni, D.; Cimatti, A. +57 more
Context: For more than two decades we have known that galaxy morphological segregation is present in the Local Universe. It is important to see how this relation evolves with cosmic time.
Aims: To investigate how galaxy assembly took place with cosmic time, we explore the evolution of the morphology-density relation up to redshift z ~ 1 using …
Transit spectrophotometry of the exoplanet HD 189733b. I. Searching for water but finding haze with HST NICMOS
Vidal-Madjar, A.; Sing, D. K.; Ballester, G. E. +5 more
We present Hubble Space Telescope near-infrared transit photometry of the nearby hot-Jupiter
Hot stars observed by XMM-Newton. I. The catalog and the properties of OB stars
Nazé, Y.
Aims: Following the advent of increasingly sensitive X-ray observatories, deep observations of early-type stars became possible. However, the results for only a few objects or clusters have until now been reported and there has been no large survey comparable to that based upon the ROSAT All-Sky Survey (RASS).
Methods: A limited survey of X-ra…
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…