Search Publications
Hertzsprung-Russell diagram and mass distribution of barium stars
Jorissen, A.; Pourbaix, D.; Escorza, A. +6 more
With the availability of parallaxes provided by the Tycho-Gaia Astrometric Solution, it is possible to construct the Hertzsprung-Russell diagram (HRD) of barium and related stars with unprecedented accuracy. A direct result from the derived HRD is that subgiant CH stars occupy the same region as barium dwarfs, contrary to what their designations i…
Hybrid modelling of cometary plasma environments. I. Impact of photoionisation, charge exchange, and electron ionisation on bow shock and cometopause at 67P/Churyumov-Gerasimenko
Kallio, E.; Gunell, H.; Behar, E. +7 more
Context. The ESA/Rosetta mission made it possible to monitor the plasma environment of a comet, from near aphelion to perihelion conditions. To understand the complex dynamics and plasma structures found at the comet, a modelling effort must be carried out in parallel.
Aims: Firstly, we present a 3D hybrid model of the cometary plasma environ…
Gas kinematics in powerful radio galaxies at z 2: Energy supply from star formation, AGN, and radio jets
Seymour, N.; De Breuck, C.; Nesvadba, N. P. H. +3 more
We compare the kinetic energy and momentum injection rates from intense star formation, bolometric AGN radiation, and radio jets with the kinetic energy and momentum observed in the warm ionized gas in 24 powerful radio galaxies at z ~ 2. These galaxies are among our best candidates for being massive galaxies near the end of their active formation…
AGN-host connection at 0.5 < z < 2.5: A rapid evolution of AGN fraction in red galaxies during the last 10 Gyr
Wuyts, S.; Daddi, E.; Elbaz, D. +13 more
We explore the dependence of the incidence of moderate-luminosity (L0.5-8 keV = 1041.9-43.7 erg s-1) active galactic nuclei (AGNs) and the distribution of their accretion rates on host color at 0.5 <z < 2.5. Based on the deepest X-ray and UV-to-far-infrared data in the two The Great Observatories Origins Deep…
Observations of the Lyman series forest towards the redshift 7.1 quasar ULAS J1120+0641
Hewett, P. C.; Warren, S. J.; Simpson, C. +5 more
We present a 30 h integration Very Large Telescope X-shooter spectrum of the Lyman series forest towards the z = 7.084 quasar ULAS J1120+0641. The only detected transmission at S/N > 5 is confined to seven narrow spikes in the Lyα forest, over the redshift range 5.858 <z < 6.122, just longward of the wavelength of the onset of the Lyβ for…
The effects of the cluster environment on the galaxy mass-size relation in MACS J1206.2-0847
Häußler, B.; Ziegler, B.; Verdugo, M. +2 more
The dense environment of galaxy clusters strongly influences the nature of galaxies. Their abundance and diversity is imprinted on the stellar-mass-size plane. Here, we study the cause of the size distribution of a sample of 560 spectroscopic members spanning a wide dynamical range down to 108.5M⊙ (log (M)-2) in the massive C…
Multiplicity and clustering in Taurus star-forming region. I. Unexpected ultra-wide pairs of high-order multiplicity in Taurus
Duchêne, Gaspard; Moraux, Estelle; Joncour, Isabelle
Aims: This work analyses the spatial distribution of stars in Taurus with a specific focus on multiple stars and wide pairs in order to derive new constraints on star formation and early dynamical evolution scenarios.
Methods: We collected the multiplicity data of stars in Taurus to build an up-to-date stellar/multiplicity catalog. We fi…
Aperture synthesis imaging of the carbon AGB star R Sculptoris. Detection of a complex structure and a dominating spot on the stellar disk
de Gregorio-Monsalvo, I.; Eriksson, K.; Lindqvist, M. +16 more
Aims: We present near-infrared interferometry of the carbon-rich asymptotic giant branch (AGB) star R Sculptoris (R Scl).
Methods: We employ medium spectral resolution K-band interferometry obtained with the instrument AMBER at the Very Large Telescope Interferometer (VLTI) and H-band low spectral resolution interferometric imaging obser…
Dwarf nova outbursts in intermediate polars
Hameury, J. -M.; Lasota, J. -P.
Context. The disc instability model (DIM) has been very successful in explaining the dwarf nova outbursts observed in cataclysmic variables. When, as in intermediate polars, the accreting white dwarf is magnetised, the disc is truncated at the magnetospheric radius, but for mass-transfer rates corresponding to the thermal-viscous instability such …
The VIMOS Ultra-Deep Survey: A major merger origin for the high fraction of galaxies at 2 < z < 6 with two bright clumps
Maccagni, D.; Schaerer, D.; Koekemoer, A. +12 more
The properties of stellar clumps in star-forming galaxies and their evolution over the redshift range 2 ≲ z ≲ 6 are presented and discussed in the context of the build-up of massive galaxies at early cosmic times. We focused on galaxies with spectroscopic redshifts from the VIMOS Ultra Deep Survey (VUDS) and stellar masses log 10(M…