Search Publications
A statistical analysis of dust polarization properties in ALMA observations of Class 0 protostellar cores
Louvet, F.; Hennebelle, P.; Guillet, V. +8 more
Context. Recent observational progress has challenged the dust grain-alignment theories used to explain the polarized dust emission routinely observed in star-forming cores.
Aims: In an effort to improve our understanding of the dust grain alignment mechanism(s), we have gathered a dozen ALMA maps of (sub)millimeter-wavelength polarized dust …
Facing problems in the determination of stellar temperatures and gravities: Galactic globular clusters
Bonifacio, P.; Mucciarelli, A.
We analysed red giant branch stars in 16 Galactic globular clusters, computing their atmospheric parameters both from the photometry and from excitation and ionisation balances. The spectroscopic parameters are lower than the photometric ones and this discrepancy increases with decreasing metallicity, reaching differences of ~350 K in effective te…
The signature of primordial black holes in the dark matter halos of galaxies
Hawkins, M. R. S.
Aims: The aim of this paper is to investigate the claim that stars in the lensing galaxy of a gravitationally lensed quasar system can always account for the observed microlensing of the individual quasar images.
Methods: A small sample of gravitationally lensed quasar systems was chosen where the quasar images appear to lie on the fring…
Studying the ISM at ∼10 pc scale in NGC 7793 with MUSE. I. Data description and properties of the ionised gas
Della Bruna, Lorenza; Östlin, Göran; Smith, Linda J. +10 more
Context. Studies of nearby galaxies reveal that around 50% of the total Hα luminosity in late-type spirals originates from diffuse ionised gas (DIG), which is a warm, diffuse component of the interstellar medium that can be associated with various mechanisms, the most important ones being "leaking" HII regions, evolved field stars, and shocks.
The young massive SMC cluster NGC 330 seen by MUSE. I. Observations and stellar content
Lennon, D. J.; de Mink, S. E.; de Koter, A. +9 more
Context. A majority of massive stars are part of binary systems, a large fraction of which will inevitably interact during their lives. Binary-interaction products (BiPs), that is, stars affected by such interaction, are expected to be commonly present in stellar populations. BiPs are thus a crucial ingredient in the understanding of stellar evolu…
MuSCAT2 multicolour validation of TESS candidates: an ultra-short-period substellar object around an M dwarf
Tamura, M.; Béjar, V. J. S.; Korth, J. +37 more
Context. We report the discovery of TOI 263.01 (TIC 120916706), a transiting substellar object (R = 0.87 RJup) orbiting a faint M3.5 V dwarf (V = 18.97) on a 0.56 d orbit.
Aims: We setout to determine the nature of the Transiting Exoplanet Survey Satellite (TESS) planet candidate TOI 263.01 using ground-based multicolour transit ph…
Active red giants: Close binaries versus single rapid rotators
Gaulme, Patrick; Vrard, Mathieu; McKeever, Jean +7 more
Oscillating red-giant stars have provided a wealth of asteroseismic information regarding their interiors and evolutionary states, which enables detailed studies of the Milky Way. The objective of this work is to determine what fraction of red-giant stars shows photometric rotational modulation, and understand its origin. One of the underlying que…
The final SDSS-IV/SPIDERS X-ray point source spectroscopic catalogue
Georgakakis, A.; Salvato, M.; Buchner, J. +15 more
Aims: We look to provide a detailed description of the SPectroscopic IDentification of ERosita Sources (SPIDERS) survey, an SDSS-IV programme aimed at obtaining spectroscopic classification and redshift measurements for complete samples of sufficiently bright X-ray sources.
Methods: We describe the SPIDERS X-ray Point Source Spectroscopi…
Case study of multi-temperature coronal jets for emerging flux MHD models
Nóbrega-Siverio, Daniel; Aulanier, Guillaume; Schmieder, Brigitte +4 more
Context. Hot coronal jets are a basic observed feature of the solar atmosphere whose physical origin is still actively debated.
Aims: We study six recurrent jets that occurred in active region NOAA 12644 on April 4, 2017. They are observed in all the hot filters of AIA as well as cool surges in IRIS slit-jaw high spatial and temporal resoluti…
The Gaia-ESO survey: 3D NLTE abundances in the open cluster NGC 2420 suggest atomic diffusion and turbulent mixing are at the origin of chemical abundance variations
Hansen, Camilla Juul; Serenelli, Aldo; Bergemann, Maria +10 more
Context. Atomic diffusion and mixing processes in stellar interiors influence the structure and the surface composition of stars. Some of these processes cannot yet be modelled from the first principles, and they require calibrations. This limits their applicability in stellar models used for studies of stellar populations and Galactic evolution. …