Search Publications
The amazing diversity in the hot gas content of an X-ray unbiased massive galaxy clusters sample
Andreon, S.; Moretti, A.; Trinchieri, G. +1 more
We aim to determine the intrinsic variety, at a given mass, of the properties of the intracluster medium in clusters of galaxies. This requires a cluster sample selected independently of the intracluster medium content for which reliable masses and subsequent X-ray data can be obtained. We present one such sample, consisting of 34 galaxy clusters …
Unexpected spatial intensity distributions and onset timing of solar electron events observed by closely spaced STEREO spacecraft
Gómez-Herrero, R.; Dresing, N.; Heber, B. +2 more
We present multi-spacecraft observations of four solar electron events using measurements from the Solar Electron Proton Telescope (SEPT) and the Electron Proton Helium INstrument (EPHIN) on board the STEREO and SOHO spacecraft, respectively, occurring between 11 October 2013 and 1 August 2014, during the approaching superior conjunction period of…
Magnetic fields of opposite polarity in sunspot penumbrae
Franz, M.; Schmidt, W.; Solanki, S. K. +25 more
Context. A significant part of the penumbral magnetic field returns below the surface in the very deep photosphere. For lines in the visible, a large portion of this return field can only be detected indirectly by studying its imprints on strongly asymmetric and three-lobed Stokes V profiles. Infrared lines probe a narrow layer in the very deep ph…
A multi-epoch spectroscopic study of the BAL quasar APM 08279+5255. II. Emission- and absorption-line variability time lags
Dadina, M.; Perna, M.; Trevese, D. +2 more
Context. The study of high-redshift bright quasars is crucial to gather information about the history of galaxy assembly and evolution. Variability analyses can provide useful data on the physics of quasar processes and their relation with the host galaxy.
Aims: In this study, we aim to measure the black hole mass of the bright lensed BAL QSO…
Stellar laboratories. VI. New Mo iv-vii oscillator strengths and the molybdenum abundance in the hot white dwarfs G191-B2B and RE 0503-289
Hoyer, D.; Rauch, T.; Werner, K. +3 more
Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation.
Aims: To identify molybdenum lines in the…
Deep imaging of the shell elliptical galaxy NGC 3923 with MegaCam
Cuillandre, J. -C.; Gwyn, S.; Ebrová, I. +4 more
Context. The elliptical galaxy NGC 3923 is known to be surrounded by a number of stellar shells, probable remnants of an accreted galaxy. Despite its uniqueness, the deepest images of its outskirts come from the 1980s. On the basis of the modified Newtonian dynamics (MOND), it has recently been predicted that a new shell lies in this region.
…
Planetary Radio Interferometry and Doppler Experiment (PRIDE) technique: A test case of the Mars Express Phobos fly-by
Lindqvist, M.; Molera Calvés, G.; Gurvits, L. I. +33 more
Context. The closest ever fly-by of the Martian moon Phobos, performed by the European Space Agency's Mars Express spacecraft, gives a unique opportunity to sharpen and test the Planetary Radio Interferometry and Doppler Experiments (PRIDE) technique in the interest of studying planet-satellite systems.
Aims: The aim of this work is to demons…
Weak lensing study of 16 DAFT/FADA clusters: Substructures and filaments
Clowe, Douglas; Sarron, Florian; Márquez, Isabel +7 more
While our current cosmological model places galaxy clusters at the nodes of a filament network (the cosmic web), we still struggle to detect these filaments at high redshifts. We perform a weak lensing study for a sample of 16 massive, medium-high redshift (0.4 <z< 0.9) galaxy clusters from the DAFT/FADA survey, which are imaged in at least …
Atomic-to-molecular gas phase transition triggered by the radio jet in Centaurus A
Combes, F.; Salomé, P.; Salomé, Q. +1 more
NGC 5128 (Centaurus A) is one of the best example to study AGN-feedback in the local Universe. At 13.5 kpc from the galaxy, optical filaments with recent star formation are lying along the radio-jet direction. We used the Atacama Pathfinder EXperiment (APEX) to map the CO(2-1) emission all along the filaments structure. Molecular gas mass of (8.2 …
Continued decay in the cyclotron line energy in Hercules X-1
Harrison, F. A.; Klochkov, D.; Wilms, J. +2 more
The centroid energy Ecyc of the cyclotron line in the spectrum of the binary X-ray pulsar