This compilation revises the 1991 listing of atomic data for the lighter elements from hydrogen to gallium. The tabulation emphasizes resonance lines, i.e., lines whose lower level is the ground state, or an excited fine-structure state of the ground term, and is restricted to wavelengths longward of the H I Lyman limit at 911.753 ?. All but the very weakest known and predicted electric-dipole transitions are included, but no forbidden lines. This paper has attempted to review all data published by the end of 2002.?????The tables contain the best data available to the author on ionization potentials, level designations, vacuum and air wavelengths, lower and upper energy levels, statistical weights, transition probabilities, natural damping constants (reciprocal lifetimes), oscillator strengths, and the often used combinations of log gf and log ?f. All ion stages with relevant classified lines are included. Individual components resulting from isotope shift and hyperfine structure are listed explicitly for certain species. The accompanying text provides references, explanations for the critical selection of data, and notes indicating where new measurements or calculations are needed.?????This compilation should be particularly useful in the analysis of interstellar and quasar absorption lines and other astrophysical sites where the density of particles and radiation is low enough to excite only the lowest atomic levels. The data also are relevant to the study of stellar atmospheres, and gaseous nebulae.?????An Appendix summarizes new data relevant to the similar compilation in Paper II for the elements germanium to uranium.

https://iopscience.iop.org/article/10.1086/377639/pdf

Atomic Data for Resonance Absorption Lines. III. Wavelengths Longward of the Lyman Limit for the Elements Hydrogen to Gallium

We present a high resolution spectral atlas of the HgMn star HD 175640 covering the 3040-10000 A region. UVES spectra observed with 90 000-110 000 resolving power and signal to noise ratio ranging from 200 to 400 are compared with a synthetic spectrum computed with the SYNTHE code (Kurucz 1993b). The model atmosphere is an ATLAS 12 model (Kurucz 1997) with parameters Ten = 12 000 K, log g = 3.95, ξ = 0 km s -1 . The stellar individual abundances in ATLAS 12 were derived from an iterative procedure. The starting atomic line lists downloaded from the Kurucz website have been improved and extended by examining different sources in the literature and by comparing the computed profiles with the observed spectrum. The high quality of the data allowed us to study the isotopic and hyperfine structure for several lines of Mn II, Ga II, Ba II, Pt II, Hg i, and Hg II. Numerous weak emission lines from Cr II and Ti II have been identified in the red part of the spectrum, starting at λ 5847 A. Two emission lines of C (mult. 10, mult. 9) have been observed for the first time. All Cr II and Ti II emission lines originate from the high excitation states (X low A 89 000 cm -1 for CrII and X low ≥ 62000 cm -1 for Ti II ) with large transition probabilities (log gf > -1.00). The synthetic spectrum superimposed on the observed spectrum as well as the adopted improved atomic line lists are available at the CDS and http://wwwuser.oat.ts.astro.it/castelli/stars.html.An extended discussion on each identified ion and related atomic data is available both on the quoted website and in an electronic Appendix to the paper.

/pdf/a-spectroscopic-atlas-of-the-hgmn-star-hd-175640-b9-v-lambda-xzxffa5ck3.pdf

A spectroscopic atlas of the HgMn star HD 175640 (B9 V) $\lambda\lambda$ 3040–10 000 Å

Context. The chemically peculiar stars of the upper main sequence represent a natural laboratory for the study of rare-earth elements (REE). Aims. We want to check the reliability of the energy levels and atomic line parameters for the second REE ions currently available in the literature, and obtained by means of experiments and theoretical calculations. Methods. We have obtained a UVES spectrum of a slowly rotating strongly magnetic Ap star, HD 144897, that exhibits very large overabundances of rare-earth elements. Here we present a detailed spectral analysis of this object, taking effects of non-uniform vertical distribution (stratification) of chemical elements into account. Results. We determined the photospheric abundances of 40 ions. For seven elements (Mg, Si, Ca, Ti, Cr, Mn, Fe), we obtained a stratification model that allows us to produce a satisfactory fit to the observed profiles of spectral lines of various strengths. All the stratified elements but Cr show a steep decrease in concentration toward the upper atmospheric layers; for Cr the transition from high to low concentration regions appears smoother than for the other elements. The REEs abundances, which have been determined for the first time from the lines of the first and second ions, have been found typically four dex higher than solar abundances. Our analysis of REE spectral lines provides strong support for the laboratory line classification and determination of the atomic parameters. The only remarkable exception is Nd iii, for which spectral synthesis was found to be inconsistent with the observations. We therefore performed a revision of the Nd iii classification. We confirmed the energies for 11 out of 24 odd energy levels that were classified previously, and derived the energies for additional 24 levels of Nd iii, thereby substantially increasing the number of classified Nd iii lines with corrected wavelengths and atomic parameters.

/pdf/rare-earth-elements-in-the-atmosphere-of-the-magnetic-1ymg2owkbs.pdf

Rare-earth elements in the atmosphere of the magnetic chemically peculiar star HD 144897 , New classification of the Nd III spectrum

Radiative lifetime measurements and transition probability calculations in lanthanide ions

Investigation of plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry caused by matrices with low second ionization potentials-identification of the secondary factor

Radiative lifetimes of seven excited states of Er iii have been measured using time-resolved laser-induced fluorescence following two-photon excitation. Relativistic Hartree-Fock calculations taking core-polarization effects into account are found to be in excellent agreement with the experimental results. A large set of new calculated transition probabilities is presented for many transitions of astrophysical interest. These results will be useful for investigating the composition of chemically peculiar stars.

/pdf/radiative-lifetime-measurements-and-transition-probabilities-4bkhx4np3b.pdf

Radiative lifetime measurements and transition probabilities of astrophysical interest in Er iii

The analysis of the spectrum of Yb III has been extended allowing us to establish 11 new energy level values. In addition, radiative lifetimes of two excited states of Yb III have been measured for the first time using time-resolved laser-induced fluorescence following two-photon excitation. The good agreement between experimental results and semi-empirical calculations performed with the relativistic Hartree-Fock method including core-polarization effects allows the determination of transition probabilities for 15 lines.

/pdf/experimental-and-theoretical-energy-levels-transition-2h5ckbdrge.pdf

Experimental and Theoretical Energy Levels, Transition probabilities and Radiative Lifetimes in Yb III

Natural radiative lifetimes of eight levels in Tm m were measured with the time-resolved laser-induced fluorescence (LIF) technique. Free doubly ionized thulium ions were obtained in a laser-produced plasma. Three even-parity levels were excited from the ground state with one-photon excitation, using a laser system generating pulses of 1 ns duration. Five odd-parity levels were excited from the ground state with two-photon excitation, where a picosecond laser system was employed. In both cases, the lifetimes were evaluated from transient LIF signals detected with a fast-detection system. The experimental lifetime results were compared with Hartree-Fock calculations including relativistic corrections. Good agreement was achieved for the 4f(12)6p levels while larger discrepancies are noted for some 4f(12)5d levels. (Less)

/pdf/radiative-lifetime-measurements-in-tm-iii-with-time-resolved-56tex6dvuu.pdf

V. Lokhnygin

Papers

Radiative lifetime measurements and transition probabilities of astrophysical interest in Er iii

Experimental and Theoretical Energy Levels, Transition probabilities and Radiative Lifetimes in Yb III

Radiative lifetime measurements in Tm III with time-resolved laser spectroscopy and comparisons with HFR calculations