Excitation and charge transfer in low-energy hydrogen atom collisions with neutral manganese and titanium

Grumer, Jon; Barklem, P. S.

doi:10.1051/0004-6361/201937434

Cited by 10 publications

(9 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the meantime we recommend the value found by Scott et al (2015a) Manganese (Z=25): A new solar Mn abundance analysis has been presented by Bergemann et al (2019) based on full 3D non-LTE calculations. Using the same 3D hydrodynamical solar model (Magic et al 2013) as for other elements and equipped with new ab initio inelastic Mn i+H i collisional cross-sections from Belyaev & Voronov (2017) (see also Grumer & Barklem 2020), they obtained log Mn = 5.52 ± 0.04. This is 0.10 dex larger than the result of Scott et al (2015a), namely 5.42 ± 0.04, that is based on 3D LTE model spectra combined with 3D non-LTE abundance corrections; the two results do not overlap within the error bars.…”

Section: Intermediate Mass Elements: Sodium To Calciummentioning

confidence: 99%

The chemical make-up of the Sun: A 2020 vision

Asplund,

Amarsi,

Grevesse

2021

Preprint

View full text Add to dashboard Cite

Context. The chemical composition of the Sun is a fundamental yardstick in astronomy, relative to which essentially all cosmic objects are referenced. As such, having an accurate knowledge of the solar elemental abundances is crucial for an extremely broad range of topics. Aims. We reassess the solar abundances of all 83 long-lived elements, using highly realistic solar modelling and state-of-the-art spectroscopic analysis techniques coupled with the best available atomic data and observations. Methods. The basis for our solar spectroscopic analysis is a 3D radiative-hydrodynamical model of the solar surface convection and atmosphere, which reproduces the full arsenal of key observational diagnostics. New complete and comprehensive 3-dimensional (3D) spectral line formation calculations taking into account of departures from local thermodynamic equilibrium (non-LTE) are presented for Na, Mg, K, Ca, and Fe using comprehensive model atoms with reliable radiative and collisional data. Our newly derived abundances for C, N, and O are based on a 3D non-LTE analysis of permitted and forbidden atomic lines as well as 3D LTE calculations for in total 879 molecular transitions of CH, C 2 , CO, NH, CN, and OH. Previous 3D-based calculations for another 50 elements are re-evaluated based on updated atomic data, stringent selection of lines, improved consideration of blends, and new non-LTE calculations available in the literature. For elements where spectroscopic determinations of the quiet Sun are not possible the recommended solar abundances are revisited based on complementary methods, including helioseismology (He), solar wind data from the Genesis sample return mission (noble gases), sunspot observations (four elements) and measurements of the most primitive meteorites (15 elements). Results. Our new improved analysis confirms the relatively low solar abundances of C, N, and O obtained in our previous 3Dbased studies: log C = 8.46 ± 0.04, log N = 7.83 ± 0.07, and log O = 8.69 ± 0.04. Excellent agreement between all available atomic and molecular indicators is achieved for C and O, but for N the atomic lines imply a lower abundance than for the molecular transitions for unknown reasons. The revised solar abundances for the other elements also typically agree well with our previously recommended values with just Li, F, Ne, Mg, Cl, Kr, Rb, Rh, Ba, W, Ir, and Pb differing by more than 0.05 dex. The here advocated present-day photospheric metal mass fraction is only slightly higher than our previous value, mainly due to the revised Ne abundance from Genesis solar wind measurements: X surface = 0.7438 ± 0.0054, Y surface = 0.2423 ± 0.0054, Z surface = 0.0139 ± 0.0006, and Z surface /X surface = 0.0187 ± 0.0009. Overall the solar abundances agree well with those of CI chondritic meteorites but we identify a correlation with condensation temperature such that moderately volatile elements are enhanced by ≈ 0.04 dex in the CI chondrites and refractory elements possibly depleted by ≈ 0.02 dex, conflicting with conventional wisdom...

show abstract

Section: Intermediate Mass Elements: Sodium To Calciummentioning

confidence: 99%

The chemical make-up of the Sun: A 2020 vision

Asplund,

Amarsi,

Grevesse

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…The models of Fe and Ca are based on Bergemann et al (2012) and Mashonkina et al (2007), respectively, but have been updated with new radiative and collisional data in Semenova et al (2020). Our model atom for Ni was presented in Bergemann et al (2021), whereas the Ti model is essentially the one adopted from Bergemann et al (2011), but updated with new H collisional rates from Grumer & Barklem (2020). The model atom of sodium was developed specifically for this study (Moltzer 2020).…”

Section: Nlte Correctionsmentioning

confidence: 99%

The chemical composition of globular clusters in the Local Group

Larsen

Eitner

Magg

et al. 2022

A&A

View full text Add to dashboard Cite

We present detailed chemical abundance measurements for 45 globular clusters (GCs) associated with galaxies in (and, in one case, beyond) the Local Group. The measurements are based on new high-resolution integrated-light spectra of GCs in the galaxies NGC 185, NGC 205, M 31, M 33, and NGC 2403, combined with reanalysis of previously published observations of GCs in the Fornax dSph, WLM, NGC 147, NGC 6822, and the Milky Way. The GCs cover the range −2.8 < [Fe/H] < −0.1 and we determined abundances for Fe, Na, Mg, Si, Ca, Sc, Ti, Cr, Mn, Ni, Cu, Zn, Zr, Ba, and Eu. Corrections for non local thermodynamic equilibrium effects are included for Na, Mg, Ca, Ti, Mn, Fe, Ni, and Ba, building on a recently developed procedure. For several of the galaxies, our measurements provide the first quantitative constraints on the detailed composition of their metal-poor stellar populations. Overall, the GCs in different galaxies exhibit remarkably uniform abundance patterns of the α, iron-peak, and neutron-capture elements, with a dispersion of less than 0.1 dex in [α/Fe] for the full sample. There is a hint that GCs in dwarf galaxies are slightly less α-enhanced (by ∼0.04 dex on average) than those in larger galaxies. One GC in M 33 (HM33-B) resembles the most metal-rich GCs in the Fornax dSph (Fornax 4) and NGC 6822 (SC7) by having α-element abundances closer to scaled-solar values, possibly hinting at an accretion origin. A principal components analysis shows that the α-element abundances strongly correlate with those of Na, Sc, Ni, and Zn. Several GCs with [Fe/H] < −1.5 are deficient in Mg compared to other α-elements. We find no GCs with strongly enhanced r-process abundances as reported for metal-poor stars in some ultra-faint dwarfs and the Magellanic Clouds. The similarity of the abundance patterns for metal-poor GCs in different environments points to similar early enrichment histories and only allow for minor variations in the initial mass function.

show abstract