English
Related papers

Related papers: Influence of metallicity on the near-surface effec…

200 papers

... [C]urrent stellar models predict oscillation frequencies that are systematically affected by simplified modelling of the near-surface layers. We use three-dimensional radiation hydrodynamics simulations to better model the near-surface…

Solar and Stellar Astrophysics · Physics 2016-08-31 W. H. Ball , B. Beeck , R. H. Cameron , L. Gizon

Inaccurate modelling of the near-surface layers of solar models causes a systematic difference between modelled and observed solar mode frequencies. This difference---known as the "surface effect" or "surface term"---presumably also exists…

Solar and Stellar Astrophysics · Physics 2017-11-07 Warrick H. Ball

Solar p-mode oscillations exhibit a systematic offset towards higher frequencies due to shortcomings in the 1D stellar structure models, especially, the lack of turbulent pressure in the superadiabatic layers just below the optical surface,…

Solar and Stellar Astrophysics · Physics 2016-07-06 Zazralt Magic , Achim Weiss

Accurate modelling of solar-like oscillators requires that modelled mode frequencies are corrected for the systematic shift caused by improper modelling of the near-surface layers, known as the surface effect. ... We investigate how much…

Solar and Stellar Astrophysics · Physics 2017-04-19 W. H. Ball , L. Gizon

The space-borne missions have provided us with a wealth of high-quality observational data that allows for seismic inferences of stellar interiors. This requires the computation of precise and accurate theoretical frequencies, but imperfect…

Solar and Stellar Astrophysics · Physics 2015-11-04 T. Sonoi , R. Samadi , K. Belkacem , H. -G. Ludwig , E. Caffau , B. Mosser

In asteroseismology, the surface effect refers to a disparity between the observed and the modelled frequencies in stars with solar-like oscillations. It originates from improper modelling of the surface layers. Correcting the surface…

Accurate determination of stellar rotation periods is important for estimating stellar ages as well as for understanding stellar activity and evolution. While for about thirty thousand stars in the Kepler field rotation periods can be…

Solar and Stellar Astrophysics · Physics 2020-02-05 V. Witzke , T. Reinhold , A. I. Shapiro , N. A. Krivova , S. K. Solanki

We analyse the effect on adiabatic stellar oscillation frequencies of replacing the near-surface layers in 1D stellar structure models with averaged 3D stellar surface convection simulations. The main difference is an expansion of the…

Individual mode frequencies have been detected in thousands of individual solar-like oscillators on the red giant branch (RGB). Fitting stellar models to these mode frequencies, however, is more difficult than in main-sequence stars. This…

Solar and Stellar Astrophysics · Physics 2018-05-16 W. H. Ball , N. Themeßl , S. Hekker

Normal-mode oscillation frequencies computed from stellar models differ from those which would be measured from stars with identical interior structures, because of modelling errors in the near-surface layers. These frequency differences…

Solar and Stellar Astrophysics · Physics 2021-10-20 J. M. Joel Ong , Sarbani Basu , Ian W. Roxburgh

We examine how metallicity affects convection and overshoot in the superadiabatic layer of main sequence stars. We present results from a grid of 3D radiation hydrodynamic simulations with four metallicities ($Z=0.040$, 0.020, 0.010,…

Solar and Stellar Astrophysics · Physics 2015-06-15 Joel D. Tanner , Sarbani Basu , Pierre Demarque

Observations of hot Jupiter type exoplanets suggest that their orbital period distribution depends on the metallicity of their host star. We investigate here whether the impact of the stellar metallicity on the evolution of the tidal…

Earth and Planetary Astrophysics · Physics 2017-08-23 Emeline Bolmont , Florian Gallet , Stéphane Mathis , Corinne Charbonnel , Louis Amard , Yann Alibert

Ratios of carefully selected line depths are sensitive to stellar effective temperature ($T_\mathrm{eff}$). Relations established between line-depth ratio (LDR) and $T_\mathrm{eff}$ allow one to determine $T_\mathrm{eff}$ precisely.…

Solar and Stellar Astrophysics · Physics 2019-03-04 Mingjie Jian , Noriyuki Matsunaga , Kei Fukue

1D stellar evolution codes employ rudimentary treatments of turbulent convection. For stars with convective envelopes, this leads to systematic errors in the predicted oscillation frequencies needed for asteroseismology. One way of mending…

Solar and Stellar Astrophysics · Physics 2019-02-13 Andreas Christ Sølvsten Jørgensen , Achim Weiss , George Angelou , Víctor Silva Aguirre

Solar oscillation frequencies change with the level of magnetic activity. Localizing subsurface magnetic field concentrations in the Sun with helioseismology will help us to understand the solar dynamo. Because the magnetic fields are not…

Solar and Stellar Astrophysics · Physics 2018-02-28 René Kiefer , Markus Roth

Recent results have shown unprecedented control over separation distances between two metallic elements hundreds of nanometers in size, underlying the effects of free-electron nonlocal response also at mid-infrared wavelengths. Most of…

Solar-like oscillations are stochastically excited by turbulent convection at the surface layers of the stars. We study the role of the surface metal abundance on the efficiency of the stochastic driving in the case of the CoRoT target HD…

Solar and Stellar Astrophysics · Physics 2010-01-26 R. Samadi , H. -G. Ludwig , K. Belkacem , M. J. Goupil , M. -A. Dupret

In helioseismology, there is a well-known offset between observed and computed oscillation frequencies. This offset is known to arise from improper modeling of the near-surface layers of the Sun, and a similar effect must occur for models…

Astrophysics · Physics 2009-11-13 Hans Kjeldsen , Timothy R. Bedding , Joergen Christensen-Dalsgaard

Localised modelling error in the near-surface layers of evolutionary stellar models causes the frequencies of their normal modes of oscillation to differ from those of actual stars with matching interior structures. These frequency…

Solar and Stellar Astrophysics · Physics 2021-01-13 J. M. Joel Ong , Sarbani Basu , Jean M. McKeever

We analysed the theoretical foundation of the mixing-length calibration by means of classical and global asteroseismic observables of field stars. We discussed the soundness of inferring a metallicity dependence of the mixing-length…

Solar and Stellar Astrophysics · Physics 2019-03-06 G. Valle , M. Dell'Omodarme , P. G. Prada Moroni , S. Degl'Innocenti
‹ Prev 1 2 3 10 Next ›