Sozialpsychologische Entwicklungstheorien

Garz, Detlef

doi:10.1007/978-3-322-95675-0

Cited by 15 publications

(12 citation statements)

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“…We confirmed that the NLTE corrections for optical silicon lines are negligible (Shi et al 2008;Wedemeyer 2001;Bergemann et al 2013). For the investigated four H-band Si lines, we found that the derived NLTE Garz (1973), KEL08 : Kelleher & Podobedova (2008) and KUR07 : Kurucz (2007). The log C 6 values were calculated according to Anstee & O'Mara (1991, 1995 and Barklem et al (2000).…”

Section: Nlte Effects 521 Departures Form Lte For the Si I H-band supporting

confidence: 81%

Nlte Analysis of High-Resolution H-Band Spectra. I. Neutral Silicon*

Zhang

Shi

Pan

et al. 2016

ApJ

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We investigated the reliability of our silicon atomic model and the influence of non-local thermodynamical equilibrium (NLTE) on the formation of neutral silicon (Si I) lines in the near-infrared (near-IR) H-band. We derived the differential Si abundances for 13 sample stars with high-resolution H-band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), as well as from optical spectra, both under local thermodynamical equilibrium (LTE) and NLTE conditions. We found that the differences between the Si abundances derived from the H-band and from optical lines for the same stars are less than 0.1 dex when the NLTE effects included, and that NLTE reduces the line-to-line scatter in the H-band spectra for most sample stars. These results suggest that our Si atomic model is appropriate for studying the formation of H-band Si lines. Our calculations show that the NLTE corrections of the Si I H-band lines are negative, i.e. the final Si abundances will be overestimated in LTE. The corrections for strong lines depend on surface gravity, and tend to be larger for giants, reaching ∼ −0.2 dex in our sample, and up to ∼ −0.4 dex in extreme cases of APOGEE targets. Thus, the NLTE effects should be included in deriving silicon abundances from H-band Si I lines, especially for the cases where only strong lines are available.

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Section: Nlte Effects 521 Departures Form Lte For the Si I H-band supporting

confidence: 81%

Nlte Analysis of High-Resolution H-Band Spectra. I. Neutral Silicon*

Zhang

Shi

Pan

et al. 2016

ApJ

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“…The data was refined where possible using observed finestructure energies from Martin & Zalubas (1983) and finestructure oscillator strengths from various sources via the NIST online database (Kramida et al 2015). As with the lines listed in Table 1, oscillator strengths from Garz (1973), were increased by 0.097 dex after renormalisation using the accurate lifetimes measured by O' Brian & Lawler (1991b,a).…”

Section: Comprehensive Model Atommentioning

confidence: 63%

“…Two lowexcitation violet Si i lines were also included in this study, but were not considered in the final solar abundance analysis. The oscillator strengths are those measured by Garz (1973), increased by 0.097 dex after renormalisation using the accurate lifetimes measured by O' Brian & Lawler (1991b,a…”

Section: Overviewmentioning

confidence: 95%

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The solar silicon abundance based on 3D non-LTE calculations

Amarsi

Asplund

2016

Mon. Not. R. Astron. Soc.

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We present three-dimensional (3D) non-local thermodynamic equilibrium (non-LTE) radiative transfer calculations for silicon in the solar photosphere, using an extensive model atom that includes recent, realistic neutral hydrogen collisional cross-sections. We find that photon losses in the Si i lines give rise to slightly negative non-LTE abundance corrections of the order −0.01 dex. We infer a 3D non-LTE based solar silicon abundance of lg Si = 7.51. With silicon commonly chosen to be the anchor between the photospheric and meteoritic abundances, we find that the meteoritic abundance scale remains unchanged compared with the Asplund et al. (2009)

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“…For the silicon lines used in this analysis, the f -values of Garz (1973) have been used. However, it has been pointed out by Becker et al (1980) that these log gf values must be increased by 0.10, adjusting for more accurate lifetimes than those used by Garz.…”

Section: T E S T I N G B Y a P P L I C At I O N T O L I N E S I N T Hmentioning

confidence: 99%

The broadening of d–f and f–d transitions by collisions with neutral hydrogen atoms

Barklem¹,

O'Mara²,

Ross³

1998

Monthly Notices of the Royal Astronomical Society

158

137

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A B S T R A C TThe theory of Anstee & O'Mara for the broadening of spectral lines owing to collisions by neutral hydrogen atoms is extended to d-f and f-d transitions of neutral atoms. Width crosssections are tabulated against effective principal quantum numbers for the upper and lower states of the transition, for a relative collision velocity of 10 4 m s ¹1 . The cross-sections are fitted to a variation with velocity of v ¹a , and results for the velocity parameter a are similarly tabulated. The data are tested by application to d-f spectral lines in the solar spectrum. The derived abundances are consistent with those for meteorites.Key words: atomic data -Sun: abundances. I N T R O D U C T I O NPreviously the theory of Anstee & O'Mara (1991, 1995 has been used to produce tables of width cross-sections for s-p and p-s transitions. The theory was recently extended to p-d and d-p transitions by Barklem & O'Mara (1997) and similar tables were presented. In this paper the theory is applied to d-f and f-d transitions.Owing to a lack of strong lines in the solar spectrum corresponding to d-f and f-d transitions, thorough testing of the theory is difficult. However, the tests presented in this paper indicate that the results are consistent with the observed broadening of lines in the solar spectrum. T H E O R YThe theory used in this work has been thoroughly covered by Anstee & O'Mara (1991, 1995 and reviewed by Barklem & O'Mara (1997).For application to d-f and f-d transitions, the theory requires only the following additions: (i) analytic expressions for the I 3jmj functions required to determine the interatomic potentials between a ground-state hydrogen atom perturber and the neutral perturbed atom in an f-state;(ii) an expression for the damping parameter hPðb; vÞi av for the d-f or f-d transition;(iii) the coupled differential equations describing the evolution of the f-state, in the laboratory frame.The I 3jmj analytic expressions were determined, although they are too lengthy to be presented here. They may be obtained on request from the authors. The S-matrix is found using the method first proposed by Roueff (1974), in which the perturber has a classical straight-line path, and the rotation of the system during the collision is included. For f-states the differential equations describing the evolution of the manifold of states are found to be

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Sozialpsychologische Entwicklungstheorien

Cited by 15 publications

References 0 publications

Nlte Analysis of High-Resolution H-Band Spectra. I. Neutral Silicon*

Nlte Analysis of High-Resolution H-Band Spectra. I. Neutral Silicon*

The solar silicon abundance based on 3D non-LTE calculations

The broadening of d–f and f–d transitions by collisions with neutral hydrogen atoms

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