Opacity Calculations for Solar Mixtures

Mondet, Guillaume; Blancard, C.; Cossé, Ph.; Faussurier, G.

doi:10.1088/0067-0049/220/1/2

Cited by 72 publications

(76 citation statements)

References 19 publications

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“…Therefore, in addition to solving the β Cep and hybrid pulsating massive stars excitation problem presented in Moravveji (2016), the success in explaining the excitation of the majority of observed modes by incorporating Fe and Ni monochromatic opacity enhancement is another manifestation that the default (OP and OPAL) opacity tables underestimate the Rosseland mean opacity in stellar interiors. Consequently, the stellar interior seems to be more opaque than was believed, and the next generation of stellar models should adopt the updated tables of Moravveji (2016) and/or Mondet et al (2015).…”

Section: Non-adiabatic Mode Stabilitymentioning

confidence: 99%

Sub-Inertial Gravity Modes in the B8v Star Kic 7760680 Reveal Moderate Core Overshooting and Low Vertical Diffusive Mixing

Moravveji

Townsend

Aerts

et al. 2016

ApJ

161

273

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Thus far, KIC 7760680 is the richest slowly pulsating B star, exhibiting 36 consecutive dipole (ℓ = 1) gravity (g-) modes. The monotonically decreasing period spacing of the series, in addition to the local dips in the pattern, confirm that KIC 7760680 is a moderate rotator with clear mode trapping in chemically inhomogeneous layers. We employ the traditional approximation of rotation to incorporate rotational effects on g-mode frequencies. Our detailed forward asteroseismic modeling of this g-mode series reveals that KIC 7760680 is a moderately rotating B star with mass ∼3.25 M e . By simultaneously matching the slope of the period spacing and the number of modes in the observed frequency range, we deduce that the equatorial rotation frequency of KIC 7760680 is 0.4805 day −1 , which is 26% of its Roche break up frequency. The relative deviation of the model frequencies and those observed is less than 1%. We succeed in tightly constraining the exponentially decaying convective core overshooting parameter to f ov ≈ 0.024 ± 0.001. This means that convective core overshooting can coexist with moderate rotation. Moreover, models with exponentially decaying overshoot from the core outperform those with the classical step-function overshoot. The best value for extra diffusive mixing in the radiatively stable envelope is confined to »  D log 0.75 0.25 ext (with D ext in cm 2 s −1 ), which is notably smaller than theoretical predictions.

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Section: Non-adiabatic Mode Stabilitymentioning

confidence: 99%

Sub-Inertial Gravity Modes in the B8v Star Kic 7760680 Reveal Moderate Core Overshooting and Low Vertical Diffusive Mixing

Moravveji

Townsend

Aerts

et al. 2016

ApJ

161

273

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“…Stellar models have thus relied on tables of opacities computed in local thermodynamic equilibrium (LTE) for a range of elements present in the system of interest. Long-term intensive efforts to produce accurate and comprehensive opacity tables have been underway for many years, with notable efforts being the Opacity Project (OP; Seaton et al 1994;Seaton & Badnell 2004;Badnell et al 2005), the Lawrence Livermore National Laboratory OPAL opacity tables (Rogers & Iglesias 1992;Iglesias & Rogers 1996), and more recently the opacity tables produced using the OPAS code (Blancard et al 2012).The OPAS code has very recently been used to compute opacities for solar mixtures (Le Pennec et al 2015;Mondet et al 2015), and improved agreement with helioseismic observations was reported. The SCO-RCG code (Pain & Gilleron 2015) also appears to be a powerful method with which to compute opacities.…”

Section: Introductionmentioning

confidence: 99%

A New Generation of Los Alamos Opacity Tables

Colgan

Kilcrease

Magee

et al. 2016

ApJ

201

167

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We present a new, publicly available set of Los Alamos OPLIB opacity tables for the elements hydrogen through zinc. Our tables are computed using the Los Alamos ATOMIC opacity and plasma modeling code, and make use of atomic structure calculations that use fine-structure detail for all the elements considered. Our equation of state model, known as ChemEOS, is based on the minimization of free energy in a chemical picture and appears to be a reasonable and robust approach to determining atomic state populations over a wide range of temperatures and densities. In this paper we discuss in detail the calculations that we have performed for the 30 elements considered, and present some comparisons of our monochromatic opacities with measurements and other opacity codes. We also use our new opacity tables in solar modeling calculations and compare and contrast such modeling with previous work.

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“…Following the derivation by Redondo in [43], the spectral axion emission can be related to monochromatic opacities provided by the Opacity Project (OP) [44,45] as well as OPAS [46,47], ATOMIC [48] and LED-COP [49]. These have to be interpolated, as they are only available on a rough grid of plasma temperatures and electron densities.…”

Section: A Metals and And The Solar Axion Fluxmentioning

confidence: 99%

“…The number of events in the peaks µ peak ∼ g 2 aγ g 2 ae have to be comparable to the fluctuation of the background which is proportional to g 4 aγ or g 2 aγ g 2 ae depending on whether the continuous part of the spectrum is dominated by the axion-photon 6.3 6.4 6.5 6.6 6.7 6.8 6. [44,45], OPAS [46,47], ATOMIC [48,58] and LEDCOP [49,58] data. For clarity, we have removed the continuous background.…”

Section: B Measuring the Peak Strengthmentioning

confidence: 99%

Axions as a probe of solar metals

Jaeckel

Thormaehlen

2019

Phys. Rev. D

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If axions or axion-like particles exist and are detected, they will not only extend the standard model of particle physics but will also open a new way to probe their sources. Axion helioscopes aim to detect axions which are produced in the core of the sun. Their spectrum contains information about the solar interior and could in principle help to solve the conflict between high and low metallicity solar models. Using the planned International Axion Observatory (IAXO) as an example, we show that helioscopes could measure the strength of characteristic emission peaks caused by the presence of heavier elements with good precision. In order to determine unambiguously the elemental abundances from this information, an improved modelling of the states of atoms inside the solar plasma is required. 4 Usually, the term axion-like particles refers particles similar to the QCD axion in that they are light (pseudo-)scalars and have very weak couplings to Standard Model particles, but they do not solve the strong CP problem. For our purposes only the two-photon and electron couplings are relevant. Their mass can be different from that of the QCD axion and can therefore be treated as a free parameter.

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Opacity Calculations for Solar Mixtures

Cited by 72 publications

References 19 publications

Sub-Inertial Gravity Modes in the B8v Star Kic 7760680 Reveal Moderate Core Overshooting and Low Vertical Diffusive Mixing

Sub-Inertial Gravity Modes in the B8v Star Kic 7760680 Reveal Moderate Core Overshooting and Low Vertical Diffusive Mixing

A New Generation of Los Alamos Opacity Tables

Axions as a probe of solar metals

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