Search Publications
How old are the stars in the halo of NGC 5128 (Centaurus A)?
Rejkuba, M.; Greggio, L.; Harris, W. E. +1 more
Context. NGC 5128 (Centaurus A) is, at the distance of just 3.8 Mpc, the nearest easily observable giant elliptical galaxy. Therefore it is the best target to investigate the early star formation history of an elliptical galaxy.
Aims: Our aims are to establish when the oldest stars formed in NGC 5128, and whether this galaxy formed stars over…
Multiwavelength campaign on Mrk 509. I. Variability and spectral energy distribution
Kaastra, J. S.; Kriss, G. A.; Arav, N. +23 more
Context. Active galactic nuclei (AGN) show a wealth of interesting physical processes, some of which are poorly understood. In a broader context, they play an important role in processes that are far beyond their immediate surroundings, owing to the high emitted power.
Aims: We want to address a number of open questions, including the locatio…
Spectral energy distributions of an AKARI-SDSS-GALEX sample of galaxies
Buat, V.; Burgarella, D.; Noll, S. +5 more
Context. The nearby universe remains the best laboratory to understand the physical properties of galaxies and is a reference for any comparison with high redshift observations. The all sky (or very large) surveys that have been performed from the ultraviolet (UV) to the far-infrared (far-IR) provide us with large datasets of very large wavelength…
Resolved photometry of extragalactic young massive star clusters
Bastian, N.; Larsen, S. S.; Smith, L. J. +6 more
Aims: We present colour-magnitude diagrams (CMDs) of young massive star clusters in several galaxies located well beyond the Local Group. The richness of these clusters allows us to obtain large samples of post-main sequence stars and test how well the observed CMDs are reproduced by canonical stellar isochrones.
Methods: We use imaging …
The XMM-LSS survey: optical assessment and properties of different X-ray selected cluster classes
Maccagni, D.; Chiappetti, L.; Altieri, B. +29 more
Context. XMM and Chandra opened a new area for the study of clusters of galaxies not only for cluster physics, but also for the detection of faint and distant clusters that were inaccessible with previous missions.
Aims: This article presents 66 spectroscopically confirmed clusters (0.05 ≤ z ≤ 1.5) within an area of 6 deg2 enclosed…
The bolometric output and host-galaxy properties of obscured AGN in the XMM-COSMOS survey
Treister, E.; Merloni, A.; Bolzonella, M. +15 more
We present a study of the multi-wavelength properties, from the mid-infrared to the hard X-rays, of a sample of 255 spectroscopically identified X-ray selected type-2 AGN from the XMM-COSMOS survey. Most of them are obscured and the X-ray absorbing column density is determined by either X-ray spectral analyses (for 45% of the sample), or from hard…
A critical analysis of the UV luminosity function at redshift ~7 from deep WFC3 data
Giavalisco, M.; Castellano, M.; Pentericci, L. +7 more
Context. The study of the luminosity function (LF) of Lyman break galaxies (LBGs) at z = 7 is very important for ascertaining their role in the reionization of the Universe. These galaxies can be used also to investigate in detail the processes of formation and evolution of galactic structures in the infancy of our Universe.
Aims: In this wor…
Direct detection of the Enceladus water torus with Herschel
Hartogh, P.; Lellouch, E.; Crovisier, J. +9 more
Cryovolcanic activity near the south pole of Saturn's moon Enceladus produces plumes of H2O-dominated gases and ice particles, which escape and populate a torus-shaped cloud. Using submillimeter spectroscopy with Herschel, we report the direct detection of the Enceladus water vapor torus in four rotational lines of water at 557, 987, 11…
The unusual protoplanetary disk around the T Tauri star ET Chamaeleontis
Ménard, F.; Duchêne, G.; Dent, W. R. F. +15 more
We present new continuum and line observations, along with modelling, of the faint (6-8) Myr old T Tauri star ET Cha belonging to the η Chamaeleontis cluster. We have acquired Herschel/PACS photometric fluxes at 70 µm and 160 µm, as well as a detection of the [OI] 63 µm fine-structure line in emission, and derived upper limits fo…
η Carinae: a very large hadron collider
Farnier, C.; Walter, R.; Leyder, J. -C.
Context. η Carinae is the colliding wind binary with the highest mass-loss rate in our Galaxy and the only one in which hard X-ray emission has been detected.
Aims: η Carinae is therefore a primary candidate to search for particle acceleration by probing its gamma-ray emission.
Methods: We used the first 21 months of Fermi/LAT data to ex…