Search Publications
A ring in a shell: the large-scale 6D structure of the Vela OB2 complex
Jordi, C.; Cantat-Gaudin, T.; Balaguer-Núñez, L. +3 more
Context. The Vela OB2 association is a group of ∼10 Myr stars exhibiting a complex spatial and kinematic substructure. The all-sky Gaia DR2 catalogue contains proper motions, parallaxes (a proxy for distance), and photometry that allow us to separate the various components of Vela OB2.
Aims: We characterise the distribution of the Vela OB2 st…
The Gaia-ESO survey: Calibrating a relationship between age and the [C/N] abundance ratio with open clusters
Gilmore, G.; Bayo, A.; Prada Moroni, P. G. +51 more
Context. In the era of large high-resolution spectroscopic surveys such as Gaia-ESO and APOGEE, high-quality spectra can contribute to our understanding of the Galactic chemical evolution by providing abundances of elements that belong to the different nucleosynthesis channels, and also by providing constraints to one of the most elusive astrophys…
Constraining disk evolution prescriptions of planet population synthesis models with observed disk masses and accretion rates
Lodato, G.; Testi, L.; Williams, J. P. +4 more
While planets are commonly discovered around main-sequence stars, the processes leading to their formation are still far from being understood. Current planet population synthesis models, which aim to describe the planet formation process from the protoplanetary disk phase to the time exoplanets are observed, rely on prescriptions for the underlyi…
Chemical (in)homogeneity and atomic diffusion in the open cluster M 67
Yong, D.; Asplund, M.; Dotter, A. +4 more
Context. The benchmark open cluster M 67 is known to have solar metallicity and an age similar to that of the Sun. It thus provides us with a great opportunity to study the properties of solar twins, as well as the evolution of Sun-like stars.
Aims: Previous spectroscopic studies of M 67 reported possible subtle changes in stellar surface abu…
LoTSS/HETDEX: Optical quasars. I. Low-frequency radio properties of optically selected quasars
Prandoni, I.; Callingham, J. R.; Shimwell, T. W. +17 more
The radio-loud/radio-quiet (RL/RQ) dichotomy in quasars is still an open question. Although it is thought that accretion onto supermassive black holes in the centre the host galaxies of quasars is responsible for some radio continuum emission, there is still a debate as to whether star formation or active galactic nuclei (AGN) activity dominate th…
Extended halo of NGC 2682 (M 67) from Gaia DR2
Jordi, C.; Cantat-Gaudin, T.; Balaguer-Núñez, L. +8 more
Context. NGC 2682 is a nearby open cluster that is approximately 3.5 Gyr old. Dynamically, most open clusters are expected to dissolve on shorter timescales of ≈1 Gyr. That it has survived until now means that NGC 2682 was likely much more massive in the past and is bound to have an interesting dynamical history.
Aims: We investigate the spat…
The RWST, a comprehensive statistical description of the non-Gaussian structures in the ISM
Boulanger, F.; Levrier, F.; Zhang, S. +5 more
The interstellar medium (ISM) is a complex nonlinear system governed by the interplay between gravity and magneto-hydrodynamics, as well as radiative, thermodynamical, and chemical processes. Our understanding of it mostly progresses through observations and numerical simulations, and a quantitative comparison between these two approaches requires…
Transiting exocomets detected in broadband light by TESS in the β Pictoris system
Zwintz, K.; Kennedy, G. M.; Zieba, S. +1 more
Aims: We search for signs of falling evaporating bodies (FEBs, also known as exocomets) in photometric time series obtained for β Pictoris after fitting and removing its δ Scuti-type pulsation frequencies.
Methods: Using photometric data obtained by the TESS satellite we determined the pulsational properties of the exoplanet host star β …
Stokes inversion based on convolutional neural networks
Asensio Ramos, A.; Díaz Baso, C. J.
Context. Spectropolarimetric inversions are routinely used in the field of solar physics for the extraction of physical information from observations. The application to two-dimensional fields of view often requires the use of supercomputers with parallelized inversion codes. Even in this case, the computing time spent on the process is still very…
Quasars as standard candles II. The non-linear relation between UV and X-ray emission at high redshifts
Vignali, C.; Lusso, E.; Salvestrini, F. +2 more
A tight non-linear relation between the X-ray and the optical-ultraviolet (UV) emission has been observed in active galactic nuclei (AGN) over a wide range of redshift and several orders of magnitude in luminosity, suggesting the existence of an ubiquitous physical mechanism regulating the energy transfer between the accretion disc and the X-ray e…