Charge transfer ionic character illustration for strontium hydride ion through a diabatic investigation

Mejrissi, Leila; Habli, Héla; Oujia, Brahim; Gadéa, Florent Xavier

doi:10.1002/qua.25680

Cited by 6 publications

(4 citation statements)

References 65 publications

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“…and byMejrissi et al (2018) provide the SrH + electronic The rate coefficients (in cm 3 /s) for the mutual neutralization processes in Sr 2+ + H − at temperature T = 6000 K as a function of the final channel excitation energy (or electron binding energy).…”

mentioning

confidence: 99%

The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis

Mashonkina

Jablonka

Sitnova

et al. 2017

A&A

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We present the non-local thermodynamic equilibrium (NLTE) abundances of up to 10 chemical species in a sample of 59 very metalpoor (VMP, −4 ≤ [Fe/H] −2) stars in seven dwarf spheroidal galaxies (dSphs) and in the Milky Way (MW) halo. Our results are based on high-resolution spectroscopic datasets and homogeneous and accurate atmospheric parameters determined in Paper I. We show that once the NLTE effects are properly taken into account, all massive galaxies in our sample, that is, the MW halo and the classical dSphs Sculptor, Ursa Minor, Sextans, and Fornax, reveal a similar plateau at [α/Fe] ≃ 0.3 for each of the α-process elements: Mg, Ca, and Ti. We put on a firm ground the evidence for a decline in α/Fe with increasing metallicity in the Boötes I ultra-faint dwarf galaxy (UFD), that is most probably due to the ejecta of type Ia supernovae. For Na/Fe, Na/Mg, and Al/Mg, the MW halo and all dSphs reveal indistinguishable trends with metallicity, suggesting that the processes of Na and Al synthesis are identical in all systems, independent of their mass. The dichotomy in the [Sr/Ba] versus [Ba/H] diagram is observed in the classical dSphs, similarly to the MW halo, calling for two different nucleosynthesis channels for Sr. We show that Sr in the massive galaxies is well correlated with Mg suggesting a strong link to massive stars and that its production is essentially independent of Ba, for most of the [Ba/H] range. Our three UFDs, that is Boötes I, UMa II, and Leo IV, are depleted in Sr and Ba relative to Fe and Mg, with very similar ratios of [Sr/Mg] ≃ −1.3 and [Ba/Mg] ≃ −1 on the entire range of their Mg abundances. The subsolar Sr/Ba ratios of Boötes I and UMa II indicate a common r-process origin of their neutron-capture elements. Sculptor remains the classical dSph, in which the evidence for inhomogeneous mixing in the early evolution stage, at [Fe/H] < −2, is the strongest.

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mentioning

confidence: 99%

The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis

Mashonkina

Jablonka

Sitnova

et al. 2017

A&A

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“…The electronic structure of a SrH + quasimolecule was studied with ab initio methods by Aymar and Dulieu [19] and more thoroughly by Mejrissi et al [20], although none of these studies were performed in a relativistic approximation and have any information about the fine structure levels of a SrH + quasimolecule.…”

Section: Processes In Sr + + H and Srmentioning

confidence: 99%

Inelastic Processes in Strontium-Hydrogen Collisions and Their Impact on Non-LTE Calculations

Yakovleva

Belyaev

Mashonkina

2022

Atoms

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Inelastic processes rate coefficients for low-energy Sr + H, Sr+ + H−, Sr+ + H, and Sr2+ + H− collisions are calculated using the multichannel quantum model approach. A total of 31 scattering channels of SrH+ and 17 scattering channels of SrH are considered. The partial cross sections and the partial rate coefficients are hence calculated for 1202 partial processes in total. Using new quantum data for Sr ii + H i collisions, we updated the model atom of Sr ii and performed the non-local thermodynamic equilibrium (non-LTE) calculations. We provide the non-LTE abundance corrections for the Sr ii resonance lines in two grids of model atmospheres, which are applicable to very metal-poor ([Fe/H] ≤−2) dwarfs and giants.

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“…The electronic structure of a SrH + quasimolecule was studied with ab initio methods by Aymar & Dulieu (2012) and more thoroughly by Mejrissi et al (2018), although none of these studies was performed in a relativistic approximation and has any information about fine structure levels of a SrH + quasimolecule.…”

Section: Processes In Sr + + H and Sr 2+ + H − Collisionsmentioning

confidence: 99%

Inelastic processes in strontium-hydrogen collisions and their impact on non-LTE calculations

Yakovleva¹,

Belyaev²,

Mashonkina³

2022

Preprint

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collisions are calculated using multichannel quantum model approach. 31 scattering channels of SrH + and 17 scattering channels of SrH are considered. The partial cross sections and the partial rate coefficients are hence calculated for 1202 partial processes in total. Using new quantum data for Sr + H collisions, we updated model atom of Sr and performed the non-local thermodynamic equilibrium (non-LTE) calculations. We provide the non-LTE abundance corrections for the Sr resonance lines in two grids of model atmospheres, which are applicable to very metal-poor ([Fe/H] ≤ −2) dwarfs and giants.

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Charge transfer ionic character illustration for strontium hydride ion through a diabatic investigation

Cited by 6 publications

References 65 publications

The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis

The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis

Inelastic Processes in Strontium-Hydrogen Collisions and Their Impact on Non-LTE Calculations

Inelastic processes in strontium-hydrogen collisions and their impact on non-LTE calculations

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