- ID:
- ivo://CDS.VizieR/J/ApJS/228/10
- Title:
- Transition probabilities for 183 lines of Cr II
- Short Name:
- J/ApJS/228/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New emission branching fraction (BF) measurements for 183 lines of the second spectrum of chromium (Cr II) and new radiative lifetime measurements from laser-induced fluorescence for 8 levels of Cr^+^ are reported. The goals of this study are to improve transition probability measurements in Cr II and reconcile solar and stellar Cr abundance values based on Cr I and Cr II lines. Eighteen spectra from three Fourier Transform Spectrometers supplemented with ultraviolet spectra from a high-resolution echelle spectrometer are used in the BF measurements. Radiative lifetimes from this study and earlier publications are used to convert the BFs into absolute transition probabilities. These new laboratory data are applied to determine the Cr abundance log{epsilon} in the Sun and metal-poor star HD 84937. The mean result in the Sun is <log{epsilon}(CrII)>=5.624+/-0.009 compared to <log{epsilon}(CrI)>=5.644+/-0.006 on a scale with the hydrogen abundance log{epsilon}(H)=12 and with the uncertainty representing only line-to-line scatter. A Saha (ionization balance) test on the photosphere of HD 84937 is also performed, yielding <log{epsilon}(CrII)>=3.417+/-0.006 and <log{epsilon}(CrI, lower level excitation potential E.P.>0eV)>=3.374+/-0.011 for this dwarf star. We find a correlation of Cr with the iron-peak element Ti, suggesting an associated nucleosynthetic production. Four iron-peak elements (Cr along with Ti, V, and Sc) appear to have a similar (or correlated) production history-other iron-peak elements appear not to be associated with Cr.
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- ID:
- ivo://CDS.VizieR/J/ApJS/162/227
- Title:
- Transition probabilities for SmII
- Short Name:
- J/ApJS/162/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radiative lifetimes, accurate to +/-5%, have been measured for 212 odd-parity levels of SmII using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for more than 900 lines of SmII. This work is the largest scale laboratory study to date of SmII transition probabilities using modern methods.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A136
- Title:
- Transition probabilities in TeII + TeIII spectra
- Short Name:
- J/A+A/551/A136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Due to the need of transition probabilities for heavy ions, including those of tellurium, in different fields of physics and in astrophysics, we have investigated theoretically the atomic structure of two selected tellurium ions (Te+ and Te++) for which no theoretical data were available so far. The first transition probabilities have been calculated for the electric dipole (E1) transitions with wavelengths shorter than 1 micrometer in Te II-III. Both the multiconfiguration Dirac-Hartree-Fock (MCDHF) method and the relativistic Hartree-Fock (HFR) approach, in which core-polarization (CPOL) effects were included, have been used for the calculations. Results. The results obtained with these two completely independent methods are in reasonable agreement. As a consequence, the transition probabilities obtained in this work are expected to be reliable. They fill in a gap concerning the radiative parameters in these two ions.
- ID:
- ivo://CDS.VizieR/J/A+A/445/361
- Title:
- Transition probabilities in the HD molecule
- Short Name:
- J/A+A/445/361
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we derive the theoretical properties of rovibrational levels belonging to excited B, C, B', and D electronic states of HD. We compute the eigenvalues and eigenfunctions of the nuclear coupled Schroedinger equations using ab initio electronic molecular properties available in the literature. Transition wavenumbers and spontaneous emission probabilities are calculated for all transitions belonging to B-X, C-X, B'-X, and D-X electronic band systems of HD when the upper rotational quantum number is below or equal to 10. We compare our results with available experimental values: the accuracy in the wavenumbers is on the order of 3 reciprocal centimetres, whereas the intensity properties are satisfactorily reproduced. The origin of the remaining discrepancies is analyzed.
- ID:
- ivo://CDS.VizieR/J/ApJS/182/51
- Title:
- Transition probabilities of rare earth elements
- Short Name:
- J/ApJS/182/51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent radiative lifetime measurements accurate to +/-5% using laser-induced fluorescence (LIF) on 43 even-parity and 15 odd-parity levels of CeII have been combined with new branching fractions measured using a Fourier transform spectrometer (FTS) to determine transition probabilities for 921 lines of CeII. This improved laboratory data set has been used to determine a new solar photospheric Ce abundance, log{epsilon}=1.61+/-0.01 ({sigma}=0.06 from 45 lines), a value in excellent agreement with the recommended meteoritic abundance, log{epsilon}=1.61+/-0.02. Revised Ce abundances have also been derived for the r-process-rich metal-poor giant stars BD+17 3248, CS 22892-052, CS 31082-001, HD 115444, and HD 221170. Between 26 and 40 lines were used for determining the Ce abundance in these five stars, yielding a small statistical uncertainty of {+/-}0.01dex similar to the solar result. The relative abundances in the metal-poor stars of Ce and Eu, a nearly pure r-process element in the Sun, matches r-process-only model predictions for solar system material. This consistent match with small scatter over a wide range of stellar metallicities lends support to these predictions of elemental fractions. A companion paper includes an interpretation of these new precision abundance results for Ce as well as new abundance results and interpretation for Pr, Dy, and Tm.
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/1203
- Title:
- Transition rates on 2s2p3 configurations in N+
- Short Name:
- J/MNRAS/462/1203
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Wavefunctions were determined using the Multi-Configuration Dirac-Hartree-Fock (MCDHF) method. The core-core, core-valence, valence correlation, Breit interaction and quantum electrodynamics (QED) effects, as well as some higher order correlation effects, were considered to obtain accurate wavelengths (lambda), oscillator strengths (gf) and transition rates (A) of 2s^2^2p^2^-2s2p^3^, 2s2p^3^-2s^2^2pnl (n>=3) and 2s2p^3^-2s2p^2^3s E1 transitions.
- ID:
- ivo://CDS.VizieR/J/A+A/587/A107
- Title:
- Transitions between Ni II bound states
- Short Name:
- J/A+A/587/A107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present rates for all E1, E2, M1, and M2 transitions among the 295 fine-structure levels of the configurations 3d^9^, 3d^8^4s, 3d^7^4s^2^, 3d^8^4p, and 3d^7^4s4p, determined through an extensive configuration interaction calculation. The CIV3 code developed by Hibbert and coworkers is used to determine for these levels configuration interaction wave functions with relativistic effects introduced through the Breit-Pauli approximation.
- ID:
- ivo://CDS.VizieR/J/A+AS/116/573
- Title:
- Transitions for FeIII
- Short Name:
- J/A+AS/116/573
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radiative transition probabilities have been calculated for states within the 3d6 configuration of Fe III. Magnetic dipole (M1) and electric quadrupole (E2) transition probabilities have been obtained using average energies, electrostatic and spin-orbit integrals adjusted so as to fit the observed energy levels. The most important configuration interaction (CI) and relativistic effects were included explicitly in the calculations, using the relativistic Hartree-Fock (HFR) method due to Cowan. The present work represents a refinement of previous monoconfigurational calculations of transition probabilities for forbidden lines of astrophysical interest in Fe III.
- ID:
- ivo://CDS.VizieR/J/ApJS/156/105
- Title:
- Transitions in L-shell ions of Fe and Ni
- Short Name:
- J/ApJS/156/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a combined configuration interaction and many-body perturbation theory approach, we calculate the level energies of 1s^2^2l^q^ and 1s^2^2l^q-1^3l' (1<=q<=8) complexes in iron and nickel ions. Comparison of 1s^2^2l^q^ energies with experimental results shows that the calculation is accurate to within ~0.15eV for these levels. The accuracy of 1s^2^2l^q-1^3l' energies can be slightly worse, at ~0.5eV. The theoretical wavelengths of 2->3 transitions of iron ions are compared with the published experimental measurements, and discrepancies are found to be mostly within {+/-}10m{AA}. Similar accuracy is expected for wavelengths of nickel ions. Such accuracy is a significant improvement over that obtainable with standard configuration interaction methods. A complete table of 2l->3l' transition wavelengths of all L-shell ions of iron and nickel is presented.
730. Transitions of CrII
- ID:
- ivo://CDS.VizieR/J/A+A/511/A68
- Title:
- Transitions of CrII
- Short Name:
- J/A+A/511/A68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To measure transition probabilities for CrII transitions from the z^4^H_J_, z^2^D_J_, y^4^F_J_ and y^4^G_J_ levels in the energy range 63000 to 68000cm^-1^. Radiative lifetimes were measured using time-resolved laser-induced fluorescence from a laser-produced plasma. In addition, branching fractions were determined from intensity calibrated spectra recorded with a UV Fourier transform spectrometer. The branching fractions and radiative lifetimes have been combined to yield accurate transition probabilities and oscillator strengths. We present laboratory measured transition probabilities for 145 CrII lines and radiative lifetimes for 14 CrII levels. The laboratory measured transition probabilities are compared to the values from semi-empirical calculations and laboratory measurements in the literature.
