A5110207416- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Solar and Space Plasma Dynamics
- Gamma-ray bursts and supernovae
- Distributed and Parallel Computing Systems
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Astronomical and nuclear sciences
- Nuclear physics research studies
- Space Exploration and Technology
- Tribology and Lubrication Engineering
- Algal biology and biofuel production
- Molecular Spectroscopy and Structure
- Atomic and Subatomic Physics Research
- Astrophysical Phenomena and Observations
- High-pressure geophysics and materials
- Quantum, superfluid, helium dynamics
- Isotope Analysis in Ecology
- Planetary Science and Exploration
Université de Montpellier
2013-2024
Centre National de la Recherche Scientifique
2013-2024
Laboratoire Univers et Particules de Montpellier
2012-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2006-2013
CEA Paris-Saclay
2006-2013
Astrophysique, Instrumentation et Modélisation
2006-2013
Université Paris Cité
2013
Institut de Recherche sur les Lois Fondamentales de l'Univers
2008-2011
DSM (Netherlands)
2010
Institute of Environmental Assessment and Water Research
2009
Rotational splittings are currently measured for several main sequence stars and a large number of red giants with the space mission Kepler. This will provide stringent constraints on rotation profiles. Our aim is to obtain seismic internal transport surface loss angular momentum oscillating solar-like stars. To this end, we study evolution rotational from pre-main red-giant branch stochastically excited oscillation modes. We modified evolutionary code CESAM2K take rotationally induced in...
Synthetic spectra are needed to determine fundamental stellar and wind parameters of all types stars. They also used for the construction theoretical spectral libraries helpful population synthesis. Therefore, a database is required allow rapid quantitative comparisons spectroscopic data. We provide such offering an unprecedented coverage entire Hertzsprung-Russell diagram. present POLLUX synthetic spectra. For objects with Teff < 6 000 K, MARCS atmosphere models computed program...
There is a large change in surface rotation rates of sun-like stars on the pre-main sequence and early main sequence. Since these have dynamo driven magnetic fields, this implies strong evolution their properties over time period. The spin-down controlled by interactions between stellar winds thus turn plays an important role rotational evolution. We present here second part study investigating large-scale fields critical observed open clusters associations with known ages 120 650 Myr, used...
We present a comprehensive analysis of the presence very massive stars (VMS > 100 M ⊙ ) in integrated spectra 13 UV-bright star-forming galaxies at 2.2 ≲ z 3.6 taken with Gran Telescopio Canarias (GTC). These have high UV absolute magnitudes ( ≃ −24), intense star formation (star rate ≃100 − 1000 yr −1 ), and metallicities range 12 + log(O/H) 8.10 8.50 inferred from strong rest-optical lines. The GTC rest-UV reveal spectral features indicative young stellar populations VMS, such as...
Aims.In this paper we study the effects of rotation in low-mass, low-metallicity RGB stars.
We review various prescriptions which have been proposed for the turbulent transport of matter and angular momentum in differentially rotating stellar radiation zones. A new prescription is presented horizontal associated with anisotropic shear turbulence produced by differential rotation latitude; this `beta-viscosity' drawn from torque measurements classical Couette-Taylor experiment (Richard & Zahn 1999). Its implementation a evolution code leads to enhanced mixing, as illustrated...
We present a first set of results concerning stellar evolution rotating low-mass stars. Our models include fully consistent transport angular momentum and chemicals due to the combined action rotation induced mixing (according Maeder & Zahn [CITE]) element segregation. The analysis effects local variations molecular weight meridional circulation on are under scope this study. apply mechanism low mass main sequence subgiant stars population I. show that so-called μ-currents major importance...
<i>Context. <i/>Recent progress and constraints brought by helio asteroseismology call for a better description of stellar interiors an accurate rotation-driven mechanisms in stars.<i>Aims. <i/>We present detailed analysis the main physical processes responsible transport angular momentum chemical species radiative regions rotating stars. We focus on cases where meridional circulation shear-induced turbulence all that are included simulations (i.e., no either internal gravity waves nor...
In this paper, we compare the currently available evolutionary tracks for Galactic massive stars. Our main goal is to highlight uncertainties on predicted paths. We compute stellar evolution models with codes MESA and STAREVOL. our results those of four published grids (Geneva, STERN, Padova FRANEC codes). first investigate effects overshooting, mass loss, metallicity, chemical composition. subsequently focus rotation. Finally, predictions observed properties a large sample find that all...
In this article, we aim to provide the community with dependence of habitable zone upon stellar mass, metallicity, rotation, and for various prescriptions limits zone. We use STAREVOL code study evolution continuously limits. Mass metallicity are parameters that have most dramatic effects on Conversely, a given mass rotation has only marginal effect these does not modify width The is also correlated activity (through Rossby number) depends considered. While magnetic negligible consequence in...
With the development of one-dimensional stellar evolution codes including rotation and increasing number observational data for stars various evolutionary stages, it becomes more possible to follow profile angular momentum distribution in stars. In this context, understanding interplay between convection very extended envelopes giant is important considering that all low- intermediate-mass become red giants after central hydrogen burning phase. paper, we analyze envelope using...
Solar activity and helioseismology show the limitation of standard solar model call for inclusion dynamical processes in both convective radiative zones. In this paper, we concentrate on zone. We first recall sensitivity boron neutrinos to microscopic physics included seismic models. confront neutrino predictions with all detected fluxes. Then, compute new models Sun including a detailed transport angular momentum chemicals due internal rotation that includes meridional circulation...
Context. Stars with masses in excess of 100 M ⊙ are observed the Local Universe, but they remain rare objects. Because shape mass function, expected to be present only most massive and youngest clusters. They may thus formed number highly star-forming galaxies. Aims. Very stars (VMSs) experience strong stellar winds that stronger than those their less OB-type counterparts. These therefore need taken into account evolutionary models synthetic spectra properly predict appearance VMS. Methods....
We present new yields of 26Al from Wolf--Rayet stellar winds based on rotating models which account well for numerous observed properties massive stars. study the impacts a change initial mass, metallicity and rotation velocity. also consider effects mass loss rates during phase. show that surface velocities core H--burning phase matching to ones, quantity ejected by star given is roughly doubled when are taken into account. The dependence yield is, other hand, very similar obtained...
Context. Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient or when mass transfer in binary systems occurs, chemically processed material observed at surface O and B stars.
We present an extended grid of state-of-the art stellar models for low-mass stars including updated physics (nuclear reaction rates, surface boundary condition, mass-loss rate, angular momentum transport, torque and rotation-induced mixing prescriptions). aim at evaluating the impact wind braking, realistic atmospheric treatment, rotation on structural rotational evolution from pre-main sequence to turn-off. Using STAREVOL code, we provide PMS grid. compute 7 different metallicities, [Fe/H]...
AGB stars have long been held responsible for the important star-to-star variations in light elements observed Galactic globular clusters. We analyse main impacts of a first generation rotating intermediate-mass on chemical properties second-generation cluster stars. The models were computed without magnetic fields and effects internal gravity waves. They account transports by meridional currents turbulence. evolution both standard stellar with initial masses between 2.5 8 Msun within...
New models of rotating and non-rotating stars are computed for initial masses between 25 120 metallicities , 0.008, 0.020, 0.040 with the aim reexamining wind contribution Wolf-Rayet (WR) to 19F enrichment interstellar medium. Models an rotation velocity found globally eject less than models. We compare our new predictions those Meynet & Arnould (2000, A&A, 355, 176), demonstrate that yields very sensitive still uncertain rate adopted mass loss rates. Using recommended values take into...
Context. Binaries in double-lined spectroscopic systems (SB2) provide a homogeneous set of stars. Differences parameters, such as age or initial conditions, which otherwise would have strong impact on the stellar evolution, can be neglected. The observed differences are determined by difference mass between two components. ratio with much higher accuracy than actual mass. Aim. In this work, we aim to study eccentric binary system KIC 9163796, whose components very close and both...