J/A+A/690/A128 Solar beryllium abundance revisited (Amarsi+, 2024)
The solar beryllium abundance revisited with 3D non-LTE models.
Amarsi A.M., Ogneva D., Buldgen G., Zhou Y., Barklem P.S.
<Astron. Astrophys. 690, A128 (2024)>
=2024A&A...690A.128A 2024A&A...690A.128A (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics ; Spectroscopy ; Models
Keywords: atomic processes - line: formation - radiative transfer -
Sun: abundances - Sun: evolution - Sun: photosphere
Abstract:
The present-day abundance of beryllium in the solar atmosphere
provides clues about mixing mechanisms within stellar interiors.
However, abundance determinations based on the BeII 313.107nm line
are prone to systematic errors due to imperfect model spectra. These
errors arise from missing continuous opacity in the UV, a significant
unidentified blend at 313.102nm, departures from local thermodynamic
equilibrium (LTE), and microturbulence and macroturbulence fudge
parameters associated with one-dimensional (1D) hydrostatic model
atmospheres. Although these factors have been discussed in the
literature, no study has yet accounted for all of them simultaneously.
To address this, we present 3D non-LTE calculations for neutral and
ionised beryllium in the Sun. We used these models to derive the
present-day solar beryllium abundance, calibrating the missing opacity
on high resolution solar irradiance data and the unidentified blend on
the centre-to-limb variation. We find a surface abundance of
1.21±0.05dex, which is significantly lower than the value of 1.38dex
that has been commonly adopted since 2004. Taking the protosolar
beryllium abundance via CI chondrites, 1.32±0.04dex, our result
implies that the surface abundance of beryllium has been depleted by
0.11±0.06dex, or 22±11%. This is in tension with standard solar
models, which predict negligible depletion, as well as with
contemporary solar models that have extra mixing calibrated on the
abundances of helium and lithium, which predict excessive depletion.
These discrepancies highlight the need for further improvements to the
physics in solar and stellar models.
Description:
Table 2 contains synthetic, continuum-normalised 3D LTE and 3D non-LTE
spectra for the disc-centre (mu=1.0) intensity, limb (mu=0.2)
intensity, and disc-integrated flux. These synthetic spectra are
provided as a function of wavelength (provided in both vacuum and
air). These synthetic spectra are parameterised in terms of beryllium
abundance, the oscillator strength of the hypothetical blend, the
wavelength of the hypothetical blend, and the scale factor to the
continuous opacity. The synthetic spectra are provided including all
blending lines (74 background lines plus the hypothetical blend plus
the Be 313.107nm line). Synthetic spectra for just the Be 313.107nm
line alone are also provided. The synthetic spectra have already
folded in instrumental broadening corresponding to R=3x105; the
disc-integrated fluxes moreover have folded in rotational broadening
of vsini=2km/s. Please contact the first author if additional data are
desired.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 141 18180 Synthetic spectra
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 F4.2 --- A(Be) Beryllium abundance
6- 10 F5.2 [-] Blendloggf log(gf) of hypothetical blend
12- 20 F9.5 nm BlendWlvac Wavelength of hypothetical blend in vacuum
22- 30 F9.5 nm BlendWlair Wavelength of hypothetical blend in air
32- 35 F4.2 --- ScaleFactor Continuous opacity scale factor
37- 46 F10.6 nm Wlvac Wavelength in vacuum
48- 57 F10.6 nm Wlair Wavelength in air
59- 64 F6.4 --- I(1.0)3N Disc-centre intensity, 3D NLTE, blended (1)
66- 71 F6.4 --- I(0.2)3N Limb(mu=0.2) intensity, 3D NLTE, blended (1)
73- 78 F6.4 --- F3N Disc-integrated flux, 3D NLTE, blended (2)
80- 85 F6.4 --- I(1.0)3L Disc-centre intensity, 3D LTE, blended (1)
87- 92 F6.4 --- I(0.2)3L Limb(mu=0.2) intensity, 3D LTE, blended (1)
94- 99 F6.4 --- F3L Disc-integrated flux, 3D LTE, blended (2)
101-106 F6.4 --- I(1.0)3NBe Disc-centre intensity, 3D NLTE, only Be (1)
108-113 F6.4 --- I(0.2)3NBe Limb(mu=0.2) intensity, 3D NLTE, only Be (1)
115-120 F6.4 --- F3NBe Disc-integrated flux, 3D NLTE, only Be (2)
122-127 F6.4 --- I(1.0)3LBe Disc-centre intensity, 3D NLTE, only Be (1)
129-134 F6.4 --- I(0.2)3LBe Limb(mu=0.2) intensity, 3D NLTE, only Be (1)
136-141 F6.4 --- F3LBe Disc-integrated flux, 3D NLTE, only Be (2)
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Note (1): Instrumental broadening applied, corresponding to R=3x105.
Note (2): Instrumental and rotational broadening applied, corresponding to
R=3x105 and vsini=2km/s.
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Acknowledgements:
Anish Amarsi, anish.amarsi(at)physics.uu.se
(End) Patricia Vannier [CDS] 26-Aug-2024