Search Publications
Evidence of quasi-chemically homogeneous evolution of massive stars up to solar metallicity
Martins, F.; Mahy, L.; Russeil, D. +1 more
Context. Long soft gamma-ray bursts (LGRBs) are usually associated with the death of the most massive stars. A large amount of core angular momentum in the phases preceding the explosion is required to form LGRBs. A very high initial rotational velocity can provide this angular momentum. This velocity strongly influences the way the star evolves: …
Long-term variability of extragalactic radio sources in the Planck Early Release Compact Source Catalogue
Dickinson, C.; López-Caniego, M.; Partridge, B. +5 more
Combining measurements taken using the Wilkinson Microwave Anisotropy Probe (WMAP) from 2001 to 2008 with measurements taken using Planck from 2009 to 2010, we investigate the long-term flux density variability of extragalactic radio sources selected from the Planck Early Release Compact Source Catalogue. The single-year, single-frequency WMAP map…
Spatially extended OH+ emission from the Orion Bar and Ridge
Ossenkopf, V.; Nagy, Z.; Bergin, E. A. +5 more
Context. The reactive HnO+ ions (OH+, H2O+ and H3O+) are widespread in the interstellar medium and act as precursors to the H2O molecule. While HnO+ absorption is seen on many Galactic lines of sight, active galactic nuclei often show the …
Improved methods for determining the kinematics of coronal mass ejections and coronal waves
Long, D. M.; Bloomfield, D. S.; Habbal, S. R. +5 more
Context. The study of solar eruptive events and associated phenomena is of great importance in the context of solar and heliophysics. Coronal mass ejections (CMEs) and coronal waves are energetic manifestations of the restructuring of the solar magnetic field and mass motion of the plasma. Characterising this motion is vital for deriving the dynam…
The 2XMMi/SDSS Galaxy Cluster Survey. II. The optically confirmed cluster sample and the LX - T relation
Takey, A.; Schwope, A.; Lamer, G.
Aims: We compile a sample of X-ray-selected galaxy groups and clusters from the XMM-Newton serendipitous source catalogue (2XMMi-DR3) with optical confirmation and redshift measurement from the Sloan Digital Sky Survey (SDSS). We present an analysis of the X-ray properties of this new sample with particular emphasis on the X-ray luminosity-te…
HDO and SO2 thermal mapping on Venus. II. The SO2 spatial distribution above and within the clouds
Encrenaz, T.; Atreya, S. K.; Bézard, B. +6 more
Sulfur dioxide and water vapor, two key species of Venus photochemistry, are known to exhibit significant spatial and temporal variations above the cloud top. In particular, ground-based thermal imaging spectroscopy at high spectral resolution, achieved on Venus in January 2012, has shown evidence for strong SO2 variations on timescales…
Multiple stellar populations in Magellanic Cloud clusters. II. Evidence also in the young NGC 1844?
Anderson, J.; Milone, A. P.; Bedin, L. R. +4 more
We used Hubble Space Telescope observations to study the young cluster NGC 1844 in the Large Magellanic Cloud (LMC). We estimated the fraction and the mass-ratio distribution of photometric binaries and report that the main sequence presents an intrinsic breadth which cannot be explained only in terms of photometric errors, and is unlikely because…
Multiwavelength campaign on Mrk 509. XI. Reverberation of the Fe Kα line
Kaastra, J. S.; Kriss, G. A.; Arav, N. +17 more
Context. We report on a detailed study of the Fe K emission/absorption complex in the nearby, bright Seyfert 1 galaxy Mrk 509. The study is part of an extensive XMM-Newton monitoring consisting of 10 pointings (~60 ks each) about once every 4 days, and includes a reanalysis of previous XMM-Newton and Chandra observations.
Aims: We aim at unde…
Diffuse light in the young cluster of galaxies CL J1449+0856 at z = 2.07
Adami, C.; Durret, F.; Guennou, L. +1 more
Context. Cluster properties do not seem to be changing significantly during their mature evolution phase; for example, they do not seem to show any strong dynamical evolution at least up to z ~ 0.5, their galaxy red sequence is already in place at least up to z ~ 1.2, and their diffuse light content remains stable up to z ~ 0.8. The question is no…
The circumstellar environment and evolutionary state of the supergiant B[e] star Wd1-9
Negueruela, I.; Clark, J. S.; Ritchie, B. W.
Context. Historically, supergiant (sg)B[e] stars have been difficult to include in theoretical schemes for the evolution of massive OB stars.
Aims: The location of Wd1-9 within the coeval starburst cluster Westerlund 1 means that it may be placed into a proper evolutionary context and we therefore aim to utilise a comprehensive multiwavelengt…