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J W Kruk - One of the best experts on this subject based on the ideXlab platform.
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Stellar laboratories viii new zr iv vii xe iv v and xe vii oscillator strengths and the al zr and xe abundances in the hot white dwarfs g191 b2b and re 0503 289
Astronomy and Astrophysics, 2017Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, Sebastien Gamrath, L Lobling, Markus DemleitnerAbstract:Context. For the spectral analysis of high-resolution and high-signal-to-noise spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. To search for zirconium and xenon lines in the ultraviolet (UV) spectra of G191−B2B and RE 0503−289, new Zr iv–vii, Xe iv–v, and Xe vii oscillator strengths were calculated. This allows, for the first time, determination of the Zr abundance in white dwarf (WD) stars and improvement of the Xe abundance determinations. Methods. We calculated Zr iv–vii, Xe iv–v, and Xe vii oscillator strengths to consider radiative and collisional bound-bound transitions of Zr and Xe in our NLTE Stellar-Atmosphere models for the analysis of their lines exhibited in UV observations of the hot WDs G191−B2B and RE 0503−289. Results. We identified one new Zr iv, 14 new Zr v, and ten new Zr vi lines in the spectrum of RE 0503−289. Zr was detected for the first time in a WD. We measured a Zr abundance of −3.5 ± 0.2 (logarithmic mass fraction, approx. 11 500 times solar). We identified five new Xe vi lines and determined a Xe abundance of −3.9 ± 0.2 (approx. 7500 times solar). We determined a preliminary photospheric Al abundance of −4.3 ± 0.2 (solar) in RE 0503−289. In the spectra of G191−B2B, no Zr line was identified. The strongest Zr iv line (1598.948 A) in our model gave an upper limit of −5.6 ± 0.3 (approx. 100 times solar). No Xe line was identified in the UV spectrum of G191−B2B and we confirmed the previously determined upper limit of −6.8 ± 0.3 (ten times solar). Conclusions. Precise measurements and calculations of atomic data are a prerequisite for advanced NLTE Stellar-Atmosphere modeling. Observed Zr iv–vi and Xe vi-vii line profiles in the UV spectrum of RE 0503−289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories viii new zr iv vii xe iv v and xe vii oscillator strengths and the al zr and xe abundances in the hot white dwarfs g191 b2b and re0503 289
arXiv: Atomic Physics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, Sebastien Gamrath, L Loebling, Markus DemleitnerAbstract:For the spectral analysis of high-resolution and high-signal-to-noise spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. To search for Zr and Xe lines in the ultraviolet (UV) spectra of G191-B2B and RE0503-289, new Zr IV-VII, Xe IV-V, and Xe VIII oscillator strengths were calculated. This allows for the first time, determination of the Zr abundance in white dwarf (WD) stars and improvement of the Xe abundance determinations. We calculated Zr IV-VII, Xe IV-V, and Xe VIII oscillator strengths to consider radiative and collisional bound-bound transitions of Zr and Xe in our NLTE Stellar-Atmosphere models for the analysis of their lines exhibited in UV observations of the hot WDs G191-B2B and RE0503-289. We identified one new Zr IV, 14 new Zr V, and ten new Zr VI lines in the spectrum of RE0503-289. Zr was detected for the first time in a WD. We measured a Zr abundance of -3.5 +/- 0.2 (logarithmic mass fraction, approx. 11 500 times solar). We dentified five new Xe VI lines and determined a Xe abundance of -3.9 +/- 0.2 (approx. 7500 times solar). We determined a preliminary photospheric Al abundance of -4.3 +/- 0.2 (solar) in RE0503-289. In the spectra of G191-B2B, no Zr line was identified. The strongest Zr IV line (1598.948 A) in our model gave an upper limit of -5.6 +/- 0.3 which is about 100 times solar. No Xe line was identified in the UV spectrum of G191-B2B and we confirmed the previously determined upper limit of -6.8 +/- 0.3 (ten times solar). Precise measurements and calculations of atomic data are a prerequisite for advanced NLTE Stellar-Atmosphere modeling. Observed Zr IV - VI and Xe VI - VII line profiles in the UV spectrum of RE0503-289 were simultaneously well reproduced.
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Stellar laboratories vii new kr iv vii oscillator strengths and an improved spectral analysis of the hot hydrogen deficient do type white dwarf re 0503 289
Astronomy and Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, P Richter, Markus DemleitnerAbstract:Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. New Kr iv–vii oscillator strengths for a large number of lines enable us to construct more detailed model atoms for our NLTE model-Atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. Methods. We calculated Kr iv–vii oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Kr lines that are exhibited in high-resolution and high S/N ultraviolet (UV) observations of the hot white dwarf RE 0503−289. Results. We reanalyzed the effective temperature and surface gravity and determined T eff = 70000 ± 2000 K and log ( g / cm s -2 ) = 7.5 ± 0.1. We newly identified ten Kr v lines and one Kr vi line in the spectrum of RE 0503−289. We measured a Kr abundance of −3.3 ± 0.3 (logarithmic mass fraction). We discovered that the interStellar absorption toward RE 0503−289 has a multi-velocity structure within a radial-velocity interval of −40 km s -1 v rad -1 . Conclusions. Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE Stellar-Atmosphere modeling. Observed Kr v–vii line profiles in the UV spectrum of the white dwarf RE 0503−289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories vii new kr iv vii oscillator strengths and an improved spectral analysis of the hot hydrogen deficient do type white dwarf re0503 289
arXiv: Solar and Stellar Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, P Richter, Markus DemleitnerAbstract:For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. New of Kr IV - VII oscillator strengths for a large number of lines allow to construct more detailed model atoms for our NLTE model-Atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. We calculated Kr IV - VII oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Kr lines exhibited in high-resolution and high-S/N ultraviolet (UV) observations of the hot white dwarf RE 0503-289. We reanalyzed the effective temperature and surface gravity and determined Teff = 70 000 +/- 2000 K and log (g / cm/s**2) = 7.5 +/- 0.1. We newly identified ten Kr V lines and one Kr VI line in the spectrum of RE 0503-289. We measured a Kr abundance of -3.3 +/- 0.3 (logarithmic mass fraction). We discovered that the interStellar absorption toward RE 0503-289 has a multi-velocity structure within a radial-velocity interval of -40 km/s < vrad < +18 km/s. Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE Stellar-Atmosphere modeling. Observed Kr V - VII line profiles in the UV spectrum of the white dwarf RE 0503-289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories vi new mo iv vii oscillator strengths and the molybdenum abundance in the hot white dwarfs g191 b2b and re 0503 289
Astronomy and Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, D Hoyer, Markus Demleitner, J W KrukAbstract:Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. To identify molybdenum lines in the ultraviolet (UV) spectra of the DA-type white dwarf G191−B2B and the DO-type white dwarf RE 0503−289 and, to determine their photospheric Mo abundances, reliable Mo iv–vii oscillator strengths are used. Methods. We newly calculated Mo iv–vii oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Mo lines exhibited in high-resolution and high S/N UV observations of RE 0503−289. Results. We identified 12 Mo v and 9 Mo vi lines in the UV spectrum of RE 0503−289 and measured a photospheric Mo abundance of 1.2−3.0 × 10 −4 (mass fraction, 22 500−56 400 times the solar abundance). In addition, from the As v and Sn iv resonance lines, we measured mass fractions of arsenic (0.5−1.3 × 10 −5 , about 300−1200 times solar) and tin (1.3−3.2 × 10 −4 , about 14 300−35 200 times solar). For G191−B2B, upper limits were determined for the abundances of Mo (5.3 × 10 −7 , 100 times solar) and, in addition, for Kr (1.1 × 10 −6 , 10 times solar) and Xe (1.7 × 10 −7 , 10 times solar). The arsenic abundance was determined (2.3−5.9 × 10 −7 , about 21−53 times solar). A new, registered German Astrophysical Virtual Observatory (GAVO) service, TOSS, has been constructed to provide weighted oscillator strengths and transition probabilities. Conclusions. Reliable measurements and calculations of atomic data are a prerequisite for Stellar-Atmosphere modeling. Observed Mo v-vi line profiles in the UV spectrum of the white dwarf RE 0503−289 were well reproduced with our newly calculated oscillator strengths. For the first time, this allowed the photospheric Mo abundance in a white dwarf to be determined.
T Rauch - One of the best experts on this subject based on the ideXlab platform.
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Stellar laboratories viii new zr iv vii xe iv v and xe vii oscillator strengths and the al zr and xe abundances in the hot white dwarfs g191 b2b and re 0503 289
Astronomy and Astrophysics, 2017Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, Sebastien Gamrath, L Lobling, Markus DemleitnerAbstract:Context. For the spectral analysis of high-resolution and high-signal-to-noise spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. To search for zirconium and xenon lines in the ultraviolet (UV) spectra of G191−B2B and RE 0503−289, new Zr iv–vii, Xe iv–v, and Xe vii oscillator strengths were calculated. This allows, for the first time, determination of the Zr abundance in white dwarf (WD) stars and improvement of the Xe abundance determinations. Methods. We calculated Zr iv–vii, Xe iv–v, and Xe vii oscillator strengths to consider radiative and collisional bound-bound transitions of Zr and Xe in our NLTE Stellar-Atmosphere models for the analysis of their lines exhibited in UV observations of the hot WDs G191−B2B and RE 0503−289. Results. We identified one new Zr iv, 14 new Zr v, and ten new Zr vi lines in the spectrum of RE 0503−289. Zr was detected for the first time in a WD. We measured a Zr abundance of −3.5 ± 0.2 (logarithmic mass fraction, approx. 11 500 times solar). We identified five new Xe vi lines and determined a Xe abundance of −3.9 ± 0.2 (approx. 7500 times solar). We determined a preliminary photospheric Al abundance of −4.3 ± 0.2 (solar) in RE 0503−289. In the spectra of G191−B2B, no Zr line was identified. The strongest Zr iv line (1598.948 A) in our model gave an upper limit of −5.6 ± 0.3 (approx. 100 times solar). No Xe line was identified in the UV spectrum of G191−B2B and we confirmed the previously determined upper limit of −6.8 ± 0.3 (ten times solar). Conclusions. Precise measurements and calculations of atomic data are a prerequisite for advanced NLTE Stellar-Atmosphere modeling. Observed Zr iv–vi and Xe vi-vii line profiles in the UV spectrum of RE 0503−289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories viii new zr iv vii xe iv v and xe vii oscillator strengths and the al zr and xe abundances in the hot white dwarfs g191 b2b and re0503 289
arXiv: Atomic Physics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, Sebastien Gamrath, L Loebling, Markus DemleitnerAbstract:For the spectral analysis of high-resolution and high-signal-to-noise spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. To search for Zr and Xe lines in the ultraviolet (UV) spectra of G191-B2B and RE0503-289, new Zr IV-VII, Xe IV-V, and Xe VIII oscillator strengths were calculated. This allows for the first time, determination of the Zr abundance in white dwarf (WD) stars and improvement of the Xe abundance determinations. We calculated Zr IV-VII, Xe IV-V, and Xe VIII oscillator strengths to consider radiative and collisional bound-bound transitions of Zr and Xe in our NLTE Stellar-Atmosphere models for the analysis of their lines exhibited in UV observations of the hot WDs G191-B2B and RE0503-289. We identified one new Zr IV, 14 new Zr V, and ten new Zr VI lines in the spectrum of RE0503-289. Zr was detected for the first time in a WD. We measured a Zr abundance of -3.5 +/- 0.2 (logarithmic mass fraction, approx. 11 500 times solar). We dentified five new Xe VI lines and determined a Xe abundance of -3.9 +/- 0.2 (approx. 7500 times solar). We determined a preliminary photospheric Al abundance of -4.3 +/- 0.2 (solar) in RE0503-289. In the spectra of G191-B2B, no Zr line was identified. The strongest Zr IV line (1598.948 A) in our model gave an upper limit of -5.6 +/- 0.3 which is about 100 times solar. No Xe line was identified in the UV spectrum of G191-B2B and we confirmed the previously determined upper limit of -6.8 +/- 0.3 (ten times solar). Precise measurements and calculations of atomic data are a prerequisite for advanced NLTE Stellar-Atmosphere modeling. Observed Zr IV - VI and Xe VI - VII line profiles in the UV spectrum of RE0503-289 were simultaneously well reproduced.
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Stellar laboratories vii new kr iv vii oscillator strengths and an improved spectral analysis of the hot hydrogen deficient do type white dwarf re 0503 289
Astronomy and Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, P Richter, Markus DemleitnerAbstract:Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. New Kr iv–vii oscillator strengths for a large number of lines enable us to construct more detailed model atoms for our NLTE model-Atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. Methods. We calculated Kr iv–vii oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Kr lines that are exhibited in high-resolution and high S/N ultraviolet (UV) observations of the hot white dwarf RE 0503−289. Results. We reanalyzed the effective temperature and surface gravity and determined T eff = 70000 ± 2000 K and log ( g / cm s -2 ) = 7.5 ± 0.1. We newly identified ten Kr v lines and one Kr vi line in the spectrum of RE 0503−289. We measured a Kr abundance of −3.3 ± 0.3 (logarithmic mass fraction). We discovered that the interStellar absorption toward RE 0503−289 has a multi-velocity structure within a radial-velocity interval of −40 km s -1 v rad -1 . Conclusions. Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE Stellar-Atmosphere modeling. Observed Kr v–vii line profiles in the UV spectrum of the white dwarf RE 0503−289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories vii new kr iv vii oscillator strengths and an improved spectral analysis of the hot hydrogen deficient do type white dwarf re0503 289
arXiv: Solar and Stellar Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, P Richter, Markus DemleitnerAbstract:For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. New of Kr IV - VII oscillator strengths for a large number of lines allow to construct more detailed model atoms for our NLTE model-Atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. We calculated Kr IV - VII oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Kr lines exhibited in high-resolution and high-S/N ultraviolet (UV) observations of the hot white dwarf RE 0503-289. We reanalyzed the effective temperature and surface gravity and determined Teff = 70 000 +/- 2000 K and log (g / cm/s**2) = 7.5 +/- 0.1. We newly identified ten Kr V lines and one Kr VI line in the spectrum of RE 0503-289. We measured a Kr abundance of -3.3 +/- 0.3 (logarithmic mass fraction). We discovered that the interStellar absorption toward RE 0503-289 has a multi-velocity structure within a radial-velocity interval of -40 km/s < vrad < +18 km/s. Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE Stellar-Atmosphere modeling. Observed Kr V - VII line profiles in the UV spectrum of the white dwarf RE 0503-289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories vi new mo iv vii oscillator strengths and the molybdenum abundance in the hot white dwarfs g191 b2b and re 0503 289
Astronomy and Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, D Hoyer, Markus Demleitner, J W KrukAbstract:Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. To identify molybdenum lines in the ultraviolet (UV) spectra of the DA-type white dwarf G191−B2B and the DO-type white dwarf RE 0503−289 and, to determine their photospheric Mo abundances, reliable Mo iv–vii oscillator strengths are used. Methods. We newly calculated Mo iv–vii oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Mo lines exhibited in high-resolution and high S/N UV observations of RE 0503−289. Results. We identified 12 Mo v and 9 Mo vi lines in the UV spectrum of RE 0503−289 and measured a photospheric Mo abundance of 1.2−3.0 × 10 −4 (mass fraction, 22 500−56 400 times the solar abundance). In addition, from the As v and Sn iv resonance lines, we measured mass fractions of arsenic (0.5−1.3 × 10 −5 , about 300−1200 times solar) and tin (1.3−3.2 × 10 −4 , about 14 300−35 200 times solar). For G191−B2B, upper limits were determined for the abundances of Mo (5.3 × 10 −7 , 100 times solar) and, in addition, for Kr (1.1 × 10 −6 , 10 times solar) and Xe (1.7 × 10 −7 , 10 times solar). The arsenic abundance was determined (2.3−5.9 × 10 −7 , about 21−53 times solar). A new, registered German Astrophysical Virtual Observatory (GAVO) service, TOSS, has been constructed to provide weighted oscillator strengths and transition probabilities. Conclusions. Reliable measurements and calculations of atomic data are a prerequisite for Stellar-Atmosphere modeling. Observed Mo v-vi line profiles in the UV spectrum of the white dwarf RE 0503−289 were well reproduced with our newly calculated oscillator strengths. For the first time, this allowed the photospheric Mo abundance in a white dwarf to be determined.
Pascal Quinet - One of the best experts on this subject based on the ideXlab platform.
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Stellar laboratories viii new zr iv vii xe iv v and xe vii oscillator strengths and the al zr and xe abundances in the hot white dwarfs g191 b2b and re 0503 289
Astronomy and Astrophysics, 2017Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, Sebastien Gamrath, L Lobling, Markus DemleitnerAbstract:Context. For the spectral analysis of high-resolution and high-signal-to-noise spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. To search for zirconium and xenon lines in the ultraviolet (UV) spectra of G191−B2B and RE 0503−289, new Zr iv–vii, Xe iv–v, and Xe vii oscillator strengths were calculated. This allows, for the first time, determination of the Zr abundance in white dwarf (WD) stars and improvement of the Xe abundance determinations. Methods. We calculated Zr iv–vii, Xe iv–v, and Xe vii oscillator strengths to consider radiative and collisional bound-bound transitions of Zr and Xe in our NLTE Stellar-Atmosphere models for the analysis of their lines exhibited in UV observations of the hot WDs G191−B2B and RE 0503−289. Results. We identified one new Zr iv, 14 new Zr v, and ten new Zr vi lines in the spectrum of RE 0503−289. Zr was detected for the first time in a WD. We measured a Zr abundance of −3.5 ± 0.2 (logarithmic mass fraction, approx. 11 500 times solar). We identified five new Xe vi lines and determined a Xe abundance of −3.9 ± 0.2 (approx. 7500 times solar). We determined a preliminary photospheric Al abundance of −4.3 ± 0.2 (solar) in RE 0503−289. In the spectra of G191−B2B, no Zr line was identified. The strongest Zr iv line (1598.948 A) in our model gave an upper limit of −5.6 ± 0.3 (approx. 100 times solar). No Xe line was identified in the UV spectrum of G191−B2B and we confirmed the previously determined upper limit of −6.8 ± 0.3 (ten times solar). Conclusions. Precise measurements and calculations of atomic data are a prerequisite for advanced NLTE Stellar-Atmosphere modeling. Observed Zr iv–vi and Xe vi-vii line profiles in the UV spectrum of RE 0503−289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories viii new zr iv vii xe iv v and xe vii oscillator strengths and the al zr and xe abundances in the hot white dwarfs g191 b2b and re0503 289
arXiv: Atomic Physics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, Sebastien Gamrath, L Loebling, Markus DemleitnerAbstract:For the spectral analysis of high-resolution and high-signal-to-noise spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. To search for Zr and Xe lines in the ultraviolet (UV) spectra of G191-B2B and RE0503-289, new Zr IV-VII, Xe IV-V, and Xe VIII oscillator strengths were calculated. This allows for the first time, determination of the Zr abundance in white dwarf (WD) stars and improvement of the Xe abundance determinations. We calculated Zr IV-VII, Xe IV-V, and Xe VIII oscillator strengths to consider radiative and collisional bound-bound transitions of Zr and Xe in our NLTE Stellar-Atmosphere models for the analysis of their lines exhibited in UV observations of the hot WDs G191-B2B and RE0503-289. We identified one new Zr IV, 14 new Zr V, and ten new Zr VI lines in the spectrum of RE0503-289. Zr was detected for the first time in a WD. We measured a Zr abundance of -3.5 +/- 0.2 (logarithmic mass fraction, approx. 11 500 times solar). We dentified five new Xe VI lines and determined a Xe abundance of -3.9 +/- 0.2 (approx. 7500 times solar). We determined a preliminary photospheric Al abundance of -4.3 +/- 0.2 (solar) in RE0503-289. In the spectra of G191-B2B, no Zr line was identified. The strongest Zr IV line (1598.948 A) in our model gave an upper limit of -5.6 +/- 0.3 which is about 100 times solar. No Xe line was identified in the UV spectrum of G191-B2B and we confirmed the previously determined upper limit of -6.8 +/- 0.3 (ten times solar). Precise measurements and calculations of atomic data are a prerequisite for advanced NLTE Stellar-Atmosphere modeling. Observed Zr IV - VI and Xe VI - VII line profiles in the UV spectrum of RE0503-289 were simultaneously well reproduced.
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Stellar laboratories vii new kr iv vii oscillator strengths and an improved spectral analysis of the hot hydrogen deficient do type white dwarf re 0503 289
Astronomy and Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, P Richter, Markus DemleitnerAbstract:Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. New Kr iv–vii oscillator strengths for a large number of lines enable us to construct more detailed model atoms for our NLTE model-Atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. Methods. We calculated Kr iv–vii oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Kr lines that are exhibited in high-resolution and high S/N ultraviolet (UV) observations of the hot white dwarf RE 0503−289. Results. We reanalyzed the effective temperature and surface gravity and determined T eff = 70000 ± 2000 K and log ( g / cm s -2 ) = 7.5 ± 0.1. We newly identified ten Kr v lines and one Kr vi line in the spectrum of RE 0503−289. We measured a Kr abundance of −3.3 ± 0.3 (logarithmic mass fraction). We discovered that the interStellar absorption toward RE 0503−289 has a multi-velocity structure within a radial-velocity interval of −40 km s -1 v rad -1 . Conclusions. Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE Stellar-Atmosphere modeling. Observed Kr v–vii line profiles in the UV spectrum of the white dwarf RE 0503−289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories vii new kr iv vii oscillator strengths and an improved spectral analysis of the hot hydrogen deficient do type white dwarf re0503 289
arXiv: Solar and Stellar Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, P Richter, Markus DemleitnerAbstract:For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. New of Kr IV - VII oscillator strengths for a large number of lines allow to construct more detailed model atoms for our NLTE model-Atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. We calculated Kr IV - VII oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Kr lines exhibited in high-resolution and high-S/N ultraviolet (UV) observations of the hot white dwarf RE 0503-289. We reanalyzed the effective temperature and surface gravity and determined Teff = 70 000 +/- 2000 K and log (g / cm/s**2) = 7.5 +/- 0.1. We newly identified ten Kr V lines and one Kr VI line in the spectrum of RE 0503-289. We measured a Kr abundance of -3.3 +/- 0.3 (logarithmic mass fraction). We discovered that the interStellar absorption toward RE 0503-289 has a multi-velocity structure within a radial-velocity interval of -40 km/s < vrad < +18 km/s. Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE Stellar-Atmosphere modeling. Observed Kr V - VII line profiles in the UV spectrum of the white dwarf RE 0503-289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories vi new mo iv vii oscillator strengths and the molybdenum abundance in the hot white dwarfs g191 b2b and re 0503 289
Astronomy and Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, D Hoyer, Markus Demleitner, J W KrukAbstract:Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. To identify molybdenum lines in the ultraviolet (UV) spectra of the DA-type white dwarf G191−B2B and the DO-type white dwarf RE 0503−289 and, to determine their photospheric Mo abundances, reliable Mo iv–vii oscillator strengths are used. Methods. We newly calculated Mo iv–vii oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Mo lines exhibited in high-resolution and high S/N UV observations of RE 0503−289. Results. We identified 12 Mo v and 9 Mo vi lines in the UV spectrum of RE 0503−289 and measured a photospheric Mo abundance of 1.2−3.0 × 10 −4 (mass fraction, 22 500−56 400 times the solar abundance). In addition, from the As v and Sn iv resonance lines, we measured mass fractions of arsenic (0.5−1.3 × 10 −5 , about 300−1200 times solar) and tin (1.3−3.2 × 10 −4 , about 14 300−35 200 times solar). For G191−B2B, upper limits were determined for the abundances of Mo (5.3 × 10 −7 , 100 times solar) and, in addition, for Kr (1.1 × 10 −6 , 10 times solar) and Xe (1.7 × 10 −7 , 10 times solar). The arsenic abundance was determined (2.3−5.9 × 10 −7 , about 21−53 times solar). A new, registered German Astrophysical Virtual Observatory (GAVO) service, TOSS, has been constructed to provide weighted oscillator strengths and transition probabilities. Conclusions. Reliable measurements and calculations of atomic data are a prerequisite for Stellar-Atmosphere modeling. Observed Mo v-vi line profiles in the UV spectrum of the white dwarf RE 0503−289 were well reproduced with our newly calculated oscillator strengths. For the first time, this allowed the photospheric Mo abundance in a white dwarf to be determined.
P H Hauschildt - One of the best experts on this subject based on the ideXlab platform.
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the mesas project long wavelength follow up observations of sirius a
The Astrophysical Journal, 2019Co-Authors: Jacob Aaron White, P H Hauschildt, J P Aufdenberg, A C Boley, Mark J Devlin, Simon Dicker, A G Hughes, A M Hughes, B S Mason, Brenda C MatthewsAbstract:Modeling the submillimeter to centimeter emission of stars is challenging due to a lack of sensitive observations at these long wavelengths. We launched an ongoing campaign to obtain new observations entitled Measuring the Emission of Stellar Atmospheres at Submillimeter/millimeter wavelengths (MESAS). Here we present Atacama Large Millimeter/submillimeter Array, Green Bank Telescope, and Very Large Array observations of Sirius A, the closest main-sequence A-type star, that span from 1.4 to 9.0 mm. These observations complement our previous millimeter data on Sirius A and are entirely consistent with the PHOENIX Stellar Atmosphere models constructed to explain them. We note that accurate models of long-wavelength emission from stars are essential not only to understand fundamental Stellar processes, but also to determine the presence of dusty debris in spatially unresolved observations of circumStellar disks.
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the mesas project long wavelength follow up observations of sirius a
arXiv: Solar and Stellar Astrophysics, 2019Co-Authors: Jacob Aaron White, P H Hauschildt, J P Aufdenberg, A C Boley, Mark J Devlin, A Hughes, Meredith A Hughes, Brian Mason, Brenda C Matthews, A MoorAbstract:Modeling the submillimeter to centimeter emission of stars is challenging due to a lack of sensitive observations at these long wavelengths. We launched an ongoing campaign to obtain new observations entitled Measuring the Emission of Stellar Atmospheres at Submillimeter/millimeter wavelengths (MESAS). Here we present ALMA, GBT, and VLA observations of Sirius A, the closest main-sequence A-type star, that span from 1.4 to 9.0 millimeters. These observations complement our previous millimeter data on Sirius A and are entirely consistent with the PHOENIX Stellar Atmosphere models constructed to explain them. We note that accurate models of long wavelength emission from stars are essential not only to understand fundamental Stellar processes, but also to determine the presence of dusty debris in spatially unresolved observations of circumStellar disks.
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a new extensive library of phoenix Stellar Atmospheres and synthetic spectra
Astronomy and Astrophysics, 2013Co-Authors: Timoliver Husser, D Homeier, Wendevon S Berg, S Dreizler, A Reiners, Travis Barman, P H HauschildtAbstract:Aims. We present a new library of high-resolution synthetic spectra based on the Stellar Atmosphere code PHOENIX that can be used for a wide range of applications of spectral analysis and Stellar parameter synthesis. Methods. The spherical mode of PHOENIX was used to create model Atmospheres and to derive detailed synthetic Stellar spectra from them. We present a new self-consistent way of describing micro-turbulence for our model Atmospheres. Results. The synthetic spectra cover the wavelength range from 500 A to 5.5 μm with resolutions of R = 500 000 in the optical and near IR, R = 100 000 in the IR and Δλ = 0.1 A in the UV. The parameter space covers 2300 K ≤ Teff ≤ 12 000 K, 0.0 ≤ log g ≤ +6.0, −4.0 ≤ [Fe/H] ≤ +1.0, and −0.2 ≤ [α/Fe] ≤ +1.2. The library is a work in progress and we expect to extend it up to Teff = 25 000 K.
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metal hydride and alkali halide opacities in extrasolar giant planets and cool Stellar Atmospheres
Proceedings of the NASA Laboratory Astrophysics Workshop, 2006Co-Authors: Philippe F Weck, P C Stancil, Kate Kirby, A Schweitzer, P H HauschildtAbstract:The lack of accurate and complete molecular line and continuum opacity data has been a serious limitation to developing atmospheric models of cool stars and Extrasolar Giant Planets (EGPs). We report our recent calculations of molecular opacities resulting from the presence of metal hydrides and alkali halides. The resulting data have been included in the PHOENIX Stellar Atmosphere code (Hauschildt & Baron 1999). The new models, calculated using spherical geometry for all gravities considered, also incorporate our latest database of nearly 670 million molecular lines, and updated equations of state.
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the molecular line opacity of mgh in cool Stellar Atmospheres
arXiv: Astrophysics, 2002Co-Authors: Philippe F Weck, P H Hauschildt, P C Stancil, Andreas Schweitzer, K KirbyAbstract:A new, complete, theoretical rotational and vibrational line list for the A-X electronic transition in MgH is presented. The list includes transition energies and oscillator strengths for all possible allowed transitions and was computed using the best available theoretical potential energies and dipole transition moment function with the former adjusted to account for experimental data. The A-X line list, as well as new line lists for the B'-X and the X-X (pure rovibrational) transitions, were included in comprehensive Stellar Atmosphere models for M, L, and T dwarfs and solar-type stars. The resulting spectra, when compared to models lacking MgH, show that MgH provides significant opacity in the visible between 4400 and 5600 Angstrom. Further, comparison of the spectra obtained with the current line list to spectra obtained using the line list constructed by Kurucz (1993) show that the Kurucz list significantly overestimates the opacity due to MgH particularly for the bands near 5150 and 4800 Angstrom with the discrepancy increasing with decreasing effective temperature.
K Werner - One of the best experts on this subject based on the ideXlab platform.
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Stellar laboratories viii new zr iv vii xe iv v and xe vii oscillator strengths and the al zr and xe abundances in the hot white dwarfs g191 b2b and re 0503 289
Astronomy and Astrophysics, 2017Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, Sebastien Gamrath, L Lobling, Markus DemleitnerAbstract:Context. For the spectral analysis of high-resolution and high-signal-to-noise spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. To search for zirconium and xenon lines in the ultraviolet (UV) spectra of G191−B2B and RE 0503−289, new Zr iv–vii, Xe iv–v, and Xe vii oscillator strengths were calculated. This allows, for the first time, determination of the Zr abundance in white dwarf (WD) stars and improvement of the Xe abundance determinations. Methods. We calculated Zr iv–vii, Xe iv–v, and Xe vii oscillator strengths to consider radiative and collisional bound-bound transitions of Zr and Xe in our NLTE Stellar-Atmosphere models for the analysis of their lines exhibited in UV observations of the hot WDs G191−B2B and RE 0503−289. Results. We identified one new Zr iv, 14 new Zr v, and ten new Zr vi lines in the spectrum of RE 0503−289. Zr was detected for the first time in a WD. We measured a Zr abundance of −3.5 ± 0.2 (logarithmic mass fraction, approx. 11 500 times solar). We identified five new Xe vi lines and determined a Xe abundance of −3.9 ± 0.2 (approx. 7500 times solar). We determined a preliminary photospheric Al abundance of −4.3 ± 0.2 (solar) in RE 0503−289. In the spectra of G191−B2B, no Zr line was identified. The strongest Zr iv line (1598.948 A) in our model gave an upper limit of −5.6 ± 0.3 (approx. 100 times solar). No Xe line was identified in the UV spectrum of G191−B2B and we confirmed the previously determined upper limit of −6.8 ± 0.3 (ten times solar). Conclusions. Precise measurements and calculations of atomic data are a prerequisite for advanced NLTE Stellar-Atmosphere modeling. Observed Zr iv–vi and Xe vi-vii line profiles in the UV spectrum of RE 0503−289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories viii new zr iv vii xe iv v and xe vii oscillator strengths and the al zr and xe abundances in the hot white dwarfs g191 b2b and re0503 289
arXiv: Atomic Physics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, Sebastien Gamrath, L Loebling, Markus DemleitnerAbstract:For the spectral analysis of high-resolution and high-signal-to-noise spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. To search for Zr and Xe lines in the ultraviolet (UV) spectra of G191-B2B and RE0503-289, new Zr IV-VII, Xe IV-V, and Xe VIII oscillator strengths were calculated. This allows for the first time, determination of the Zr abundance in white dwarf (WD) stars and improvement of the Xe abundance determinations. We calculated Zr IV-VII, Xe IV-V, and Xe VIII oscillator strengths to consider radiative and collisional bound-bound transitions of Zr and Xe in our NLTE Stellar-Atmosphere models for the analysis of their lines exhibited in UV observations of the hot WDs G191-B2B and RE0503-289. We identified one new Zr IV, 14 new Zr V, and ten new Zr VI lines in the spectrum of RE0503-289. Zr was detected for the first time in a WD. We measured a Zr abundance of -3.5 +/- 0.2 (logarithmic mass fraction, approx. 11 500 times solar). We dentified five new Xe VI lines and determined a Xe abundance of -3.9 +/- 0.2 (approx. 7500 times solar). We determined a preliminary photospheric Al abundance of -4.3 +/- 0.2 (solar) in RE0503-289. In the spectra of G191-B2B, no Zr line was identified. The strongest Zr IV line (1598.948 A) in our model gave an upper limit of -5.6 +/- 0.3 which is about 100 times solar. No Xe line was identified in the UV spectrum of G191-B2B and we confirmed the previously determined upper limit of -6.8 +/- 0.3 (ten times solar). Precise measurements and calculations of atomic data are a prerequisite for advanced NLTE Stellar-Atmosphere modeling. Observed Zr IV - VI and Xe VI - VII line profiles in the UV spectrum of RE0503-289 were simultaneously well reproduced.
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Stellar laboratories vii new kr iv vii oscillator strengths and an improved spectral analysis of the hot hydrogen deficient do type white dwarf re 0503 289
Astronomy and Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, P Richter, Markus DemleitnerAbstract:Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. New Kr iv–vii oscillator strengths for a large number of lines enable us to construct more detailed model atoms for our NLTE model-Atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. Methods. We calculated Kr iv–vii oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Kr lines that are exhibited in high-resolution and high S/N ultraviolet (UV) observations of the hot white dwarf RE 0503−289. Results. We reanalyzed the effective temperature and surface gravity and determined T eff = 70000 ± 2000 K and log ( g / cm s -2 ) = 7.5 ± 0.1. We newly identified ten Kr v lines and one Kr vi line in the spectrum of RE 0503−289. We measured a Kr abundance of −3.3 ± 0.3 (logarithmic mass fraction). We discovered that the interStellar absorption toward RE 0503−289 has a multi-velocity structure within a radial-velocity interval of −40 km s -1 v rad -1 . Conclusions. Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE Stellar-Atmosphere modeling. Observed Kr v–vii line profiles in the UV spectrum of the white dwarf RE 0503−289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories vii new kr iv vii oscillator strengths and an improved spectral analysis of the hot hydrogen deficient do type white dwarf re0503 289
arXiv: Solar and Stellar Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, J W Kruk, D Hoyer, P Richter, Markus DemleitnerAbstract:For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. New of Kr IV - VII oscillator strengths for a large number of lines allow to construct more detailed model atoms for our NLTE model-Atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. We calculated Kr IV - VII oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Kr lines exhibited in high-resolution and high-S/N ultraviolet (UV) observations of the hot white dwarf RE 0503-289. We reanalyzed the effective temperature and surface gravity and determined Teff = 70 000 +/- 2000 K and log (g / cm/s**2) = 7.5 +/- 0.1. We newly identified ten Kr V lines and one Kr VI line in the spectrum of RE 0503-289. We measured a Kr abundance of -3.3 +/- 0.3 (logarithmic mass fraction). We discovered that the interStellar absorption toward RE 0503-289 has a multi-velocity structure within a radial-velocity interval of -40 km/s < vrad < +18 km/s. Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE Stellar-Atmosphere modeling. Observed Kr V - VII line profiles in the UV spectrum of the white dwarf RE 0503-289 were simultaneously well reproduced with our newly calculated oscillator strengths.
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Stellar laboratories vi new mo iv vii oscillator strengths and the molybdenum abundance in the hot white dwarfs g191 b2b and re 0503 289
Astronomy and Astrophysics, 2016Co-Authors: T Rauch, K Werner, Pascal Quinet, D Hoyer, Markus Demleitner, J W KrukAbstract:Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model Atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. To identify molybdenum lines in the ultraviolet (UV) spectra of the DA-type white dwarf G191−B2B and the DO-type white dwarf RE 0503−289 and, to determine their photospheric Mo abundances, reliable Mo iv–vii oscillator strengths are used. Methods. We newly calculated Mo iv–vii oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE Stellar-Atmosphere models for the analysis of Mo lines exhibited in high-resolution and high S/N UV observations of RE 0503−289. Results. We identified 12 Mo v and 9 Mo vi lines in the UV spectrum of RE 0503−289 and measured a photospheric Mo abundance of 1.2−3.0 × 10 −4 (mass fraction, 22 500−56 400 times the solar abundance). In addition, from the As v and Sn iv resonance lines, we measured mass fractions of arsenic (0.5−1.3 × 10 −5 , about 300−1200 times solar) and tin (1.3−3.2 × 10 −4 , about 14 300−35 200 times solar). For G191−B2B, upper limits were determined for the abundances of Mo (5.3 × 10 −7 , 100 times solar) and, in addition, for Kr (1.1 × 10 −6 , 10 times solar) and Xe (1.7 × 10 −7 , 10 times solar). The arsenic abundance was determined (2.3−5.9 × 10 −7 , about 21−53 times solar). A new, registered German Astrophysical Virtual Observatory (GAVO) service, TOSS, has been constructed to provide weighted oscillator strengths and transition probabilities. Conclusions. Reliable measurements and calculations of atomic data are a prerequisite for Stellar-Atmosphere modeling. Observed Mo v-vi line profiles in the UV spectrum of the white dwarf RE 0503−289 were well reproduced with our newly calculated oscillator strengths. For the first time, this allowed the photospheric Mo abundance in a white dwarf to be determined.
