Asteroseismology of the β Cephei star ν Eridani – II. Spectroscopic observations and pulsational frequency analysis     

C. Aerts  P. De Cat  G. Handler  U. Heiter  L. A. Balona  J. Krzesinski  P. Mathias  H. Lehmann  I. Ilyin  J. De Ridder  S. Dreizler  A. Bruch  I. Traulsen  A. Hoffmann  D. James  E. Romero-Colmenero  T. Maas  M. A. T. Groenewegen  J. H. Telting  K. Uytterhoeven  C. Koen  P. L. Cottrell  J. Bentley  D. J. Wright  J. Cuypers 《Monthly notices of the Royal Astronomical Society》2004,347(2):463-470

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Relative astrometry and near‐infrared differential photometry of nearby southern orbital binaries with adaptive optics     

P. Lampens  J.‐L. Prieur  R.W. Argyle  J. Cuypers 《Astronomische Nachrichten》2013,334(3):237-250

We present relative astrometry and differential photometry measurements for a sample of nearby southern orbital binaries making use of the technique of Adaptive Optics. The observations were made in December 2000, with the ADONIS camera mounted at the 3.6‐m ESO telescope from La Silla Observatory, equipped with the broad‐band near‐infrared filters (J ‐, H ‐, K ‐passbands). Our sample contains stars which do not fit very well the empirical mean mass‐luminosity relation (according to our previous study), but for which accurate parallaxes (determined by the Hipparcos satellite) and high‐quality orbits were available thanks to many previous efforts. We derived accurate positions and J, H, K magnitudes of the individual components of those binaries. The individual stellar components have near‐infrared colour indices well grouped in those plots and are comparable to standard single stars. The data reduction procedure used for deriving those results is described in detail. It is based on a least‐squares fit of Moffat‐Lorentz profiles in direct imaging for well‐resolved systems and on Fourier analysis for very close pairs. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Deep circulation driven by strong vertical mixing in the Timor Basin   总被引：1，自引：1，他引：0  

Yannis Cuypers  Stephane Pous  Janet Sprintall  Agus Atmadipoera  Gurvan Madec  Robert Molcard 《Ocean Dynamics》2017,67(2):191-209

The importance of deep mixing in driving the deep part of the overturning circulation has been a long debated question at the global scale. Our observations provide an illustration of this process at the Timor Basin scale of ～1000 km. Long-term averaged moored velocity data at the Timor western sill suggest that a deep circulation is present in the Timor Basin. An inflow transport of ～0.15 Sv is observed between 1600 m and the bottom at 1890 m. Since the basin is closed on its eastern side below 1250 m depth, a return flow must be generated above 1600 m with a ～0.15 Sv outflow. The vertical turbulent diffusivity is inferred from a heat and transport balance at the basin scale and from Thorpe scale analysis. Basin averaged vertical diffusivity is as large as 1 × 10^?3 m² s^?1. Observations are compared with regional low-resolution numerical simulations, and the deep observed circulation is only recovered when a strong vertical diffusivity resulting from the parameterization of internal tidal mixing is considered. Furthermore, the deep vertical mixing appears to be strongly dependent on the choice of the internal tide mixing parameterization and also on the prescribed value of the mixing efficiency.  相似文献   

Contrasted turbulence intensities in the Indonesian Throughflow: a challenge for parameterizing energy dissipation rate     

Pascale Bouruet-Aubertot  Yannis Cuypers  Bruno Ferron  Denis Dausse  Olivier Ménage  Agus Atmadipoera  Indra Jaya 《Ocean Dynamics》2018,68(7):779-800

Microstructure measurements were performed along two sections through the Halmahera Sea and the Ombai Strait and at a station in the deep Banda Sea. Contrasting dissipation rates (??) and vertical eddy diffusivities (K _z ) were obtained with depth-averaged ranges of \(\sim [9 \times 10^{-10}-10^{-5}]\) W kg^??1 and of \(\sim [1 \times 10^{-5}-2 \times 10^{-3}]\) m² s^??1, respectively. Similarly, turbulence intensity, \(I={\epsilon }/(\nu N^{2})\) with ν the kinematic viscosity and N the buoyancy frequency, was found to vary seven orders of magnitude with values up to \(10^{7}\). These large ranges of variations were correlated with the internal tide energy level, which highlights the contrast between regions close and far from internal tide generations. Finescale parameterizations of ?? induced by the breaking of weakly nonlinear internal waves were only relevant in regions located far from any generation area (“far field”), at the deep Banda Sea station. Closer to generation areas, at the “intermediate field” station of the Halmahera Sea, a modified formulation of MacKinnon and Gregg (2005) was validated for moderately turbulent regimes with 100 < I < 1000. Near generation areas marked by strong turbulent regimes such as “near field” stations within strait and passages, ?? is most adequately inferred from horizontal velocities provided that part of the inertial subrange is resolved, according to Kolmogorov scaling.  相似文献   

Mixing efficiency from microstructure measurements in the Sicily Channel     

Vladoiu  Anda  Bouruet-Aubertot  Pascale  Cuypers  Yannis  Ferron  Bruno  Schroeder  Katrin  Borghini  Mireno  Leizour  Stephane  Ismail  Sana Ben 《Ocean Dynamics》2019,69(7):787-807

Ocean Dynamics - The dissipation flux coefficient, a measure of the mixing efficiency of a turbulent flow, was computed from microstructure measurements collected with a vertical microstructure...  相似文献