Search Publications
New ultra-cool and brown dwarf candidates in Gaia DR2
Reylé, C.
Context. The second Gaia data release (Gaia DR2) contains high-precision positions, parallaxes, and proper motions for 1.3 billion sources. The resulting Hertzsprung-Russel diagram reveals fine structures throughout the mass range.
Aims: This paper aims to investigate the content of Gaia DR2 at the low-mass end and to characterize ultra-cool …
Vaex: big data exploration in the era of Gaia
Veljanoski, Jovan; Breddels, Maarten A.
We present a new Python library, called vaex, intended to handle extremely large tabular datasets such as astronomical catalogues like the Gaia catalogue, N-body simulations, or other datasets which can be structured in rows and columns. Fast computations of statistics on regular N-dimensional grids allows analysis and visualization in the order o…
Shock location and CME 3D reconstruction of a solar type II radio burst with LOFAR
Eislöffel, J.; Mann, G.; Anderson, J. +62 more
Context. Type II radio bursts are evidence of shocks in the solar atmosphere and inner heliosphere that emit radio waves ranging from sub-meter to kilometer lengths. These shocks may be associated with coronal mass ejections (CMEs) and reach speeds higher than the local magnetosonic speed. Radio imaging of decameter wavelengths (20-90 MHz) is now …
Lithium abundance patterns of late-F stars: an in-depth analysis of the lithium desert
Aguilera-Gómez, Claudia; Chanamé, Julio; Ramírez, Iván
Aims: We address the existence and origin of the lithium (Li) desert, a region in the Li-Teff plane sparsely populated by stars. Here we analyze some of the explanations that have been suggested for this region, including mixing in the late main sequence, a Li dip origin for stars with low Li abundances in the region, and a possibl…
Testing the disk instability model of cataclysmic variables
Lasota, Jean-Pierre; Dubus, Guillaume; Otulakowska-Hypka, Magdalena
Context. The disk instability model (DIM) attributes the outbursts of dwarf novae to a thermal-viscous instability of their accretion disk, an instability to which nova-like stars are not subject.
Aims: We aim to test the fundamental prediction of the DIM: the separation of cataclysmic variables (CVs) into nova-likes and dwarf novae depending…
COSMOGRAIL. XVII. Time delays for the quadruply imaged quasar PG 1115+080
Magain, P.; Kim, S.; Frieman, J. +24 more
We present time-delay estimates for the quadruply imaged quasar PG 1115+080. Our results are based on almost daily observations for seven months at the ESO MPIA 2.2 m telescope at La Silla Observatory, reaching a signal-to-noise ratio of about 1000 per quasar image. In addition, we re-analyze existing light curves from the literature that we compl…
A collection of model stellar spectra for spectral types B to early-M
Allende Prieto, C.; Koesterke, L.; Barklem, P. S. +3 more
Context. Models of stellar spectra are necessary for interpreting light from individual stars, planets, integrated stellar populations, nebulae, and the interstellar medium.
Aims: We provide a comprehensive and homogeneous collection of synthetic spectra for a wide range of atmospheric parameters and chemical compositions.
Methods: We co…
The GJ 504 system revisited. Combining interferometric, radial velocity, and high contrast imaging data
Kuzuhara, M.; Tamura, M.; Rouan, D. +79 more
Context. The G-type star GJ504A is known to host a 3-35 MJup companion whose temperature, mass, and projected separation all contribute to making it a test case for planet formation theories and atmospheric models of giant planets and light brown dwarfs.
Aims: We aim at revisiting the system age, architecture, and companion physica…
Gas and galaxies in filaments between clusters of galaxies. The study of A399-A401
Aghanim, N.; Douspis, M.; Salomé, P. +2 more
We have performed a multi-wavelength analysis of two galaxy cluster systems selected with the thermal Sunyaev-Zel'dovich (tSZ) effect and composed of cluster pairs and an inter-cluster filament. We have focused on one pair of particular interest: A399-A401 at redshift z ~ 0.073 seperated by 3 Mpc. We have also performed the first analysis of one l…
Fraction of bolometric luminosity absorbed by dust in DustPedia galaxies
Bianchi, S.; Madden, S. C.; Galliano, F. +16 more
Aims: We aim to study the fraction of stellar radiation absorbed by dust, fabs, in 814 galaxies of different morphological types. The targets constitute the vast majority (93%) of the DustPedia sample, including almost all large (optical diameter larger than 1'), nearby (v ≤ 3000 km s-1) galaxies observed with the Hersch…