- ID:
- ivo://CDS.VizieR/J/A+A/432/1137
- Title:
- Fe XXIII Benchmarking
- Short Name:
- J/A+A/432/1137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent scattering calculations for Fe XXIII are benchmarked against laboratory and astrophysical observations. The collisional data are supplemented by radiative data obtained with empirical adjustments that take into account observed wavelengths. All previous line identifications and energy levels are reviewed and assessed in light of these new calculations. Most of the previous identifications, in particular of the astrophysically-important spectral lines are confirmed. However, some identification are rejected or questioned, and new ones proposed. The agreement between theoretical and experimental data in terms of wavelengths, line intensities and level lifetimes is very good. Observations of Fe XXIII L-shell emission lines provide a great opportunity to directly measure electron temperatures for a wide range of astrophysical sources. Examples from solar (SMM, SOLEX) and stellar (Chandra, EUVE) observations are provided. ************************************************************************** * * * Sorry, but the author(s) never supplied the tabular material * * announced in the paper * * * **************************************************************************
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- ID:
- ivo://CDS.VizieR/J/A+A/365/266
- Title:
- Fe XXIII fine structure level oscillator strengths
- Short Name:
- J/A+A/365/266
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We tabulate theoretical line strengths, f-values and transition energies for the beryllium-like ion Fe XXIII. Transitions are between levels 2l_1_2l_2_S'L'J' and 2l_3_nl_4_SLJ with n = 2, 3, 4. The calculation uses the well known configuration interaction program CIV3 in which relativistic effects are allowed for by means of the Breit-Pauli approximation. We give a detailed comparison of our oscillator strengths with those which Chen & Ong (1998, Phys. Rev. A, 58, 1070) obtained using the relativistic Dirac code GRASP2.
- ID:
- ivo://CDS.VizieR/J/A+A/484/879
- Title:
- Fe XXVI radiative and excitation rates
- Short Name:
- J/A+A/484/879
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we report on calculations for energy levels, radiative rates, collision strengths, and effective collision strengths for transitions among the lowest 25 levels of the n<=5 configurations of H-like Fe XXVI. The General purpose relativistic atomic structure package (GRASP) and Dirac atomic R-matrix code (DARC) have been adopted for the calculations.
- ID:
- ivo://CDS.VizieR/VI/29A
- Title:
- Finding list for multiplet tables of NSRDS-NBS 3
- Short Name:
- VI/29A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The primary references for stellar line identifications in the optical and ultraviolet spectral regions have been "A Multiplet Table of Astrophysical Interest" (RMT, Moore 1945) and "An Ultraviolet Multiplet Table" (UMT, Moore 1950, 1952, 1962). Dr. Charlotte Moore Sitterly has, over the last two decades, undertaken a revision of certain multiplet tables based on data derived from analyses of optical spectra. The present finding list has been prepared from the data published in the first ten sections of these revised tables: -------------------------------------------------- Section Year Elements -------------------------------------------------- 1 1965 Si II, Si III, Si IV 2 1967 Si I 3 1970 C I, C II, C III, C IV, C V, C VI 4 1970 N IV, N V, N VI, N VII 5 1975 N I, N II, N III 6 1972 H I, D I, T I 7 1976 O I 8 1979 O VI, O VII, O VIII 9 1980 O V 10 1983 O IV -------------------------------------------------- An earlier finding list containing Sections 1-7 only was published by Adelman, Adelman and Fischel (1977) (Catalogue VI/11). We have revised the format and added information to the earlier list, and have appended Sections 8-10 to produce the present version. We intend to incorporate future sections to produce new comprehensive lists as the sections are published and can be computerized. This document describes the machine version of the finding list as it is currently being distributed from the Astronomical Data Center. It is intended to enable users to read and process the data without problems and guesswork, and to interpret the various codes used in the list without recourse to the original publications. However, for additional details concerning the multiplet tables and analyses of the optical spectra, the source publications and their associated references should be consulted.
- ID:
- ivo://CDS.VizieR/J/A+A/475/765
- Title:
- Fine structure forbidden lines in FeII
- Short Name:
- J/A+A/475/765
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Absorption or emission lines of Fe II are observed in many astrophysical spectra and accurate atomic data are required to interpret these lines. The calculation of electron-impact excitation rates for transitions among even the lowest lying levels of Fe II is a formidable task for theoreticians.
- ID:
- ivo://CDS.VizieR/J/A+AS/97/443
- Title:
- Fluorescence for Be to Zn
- Short Name:
- J/A+AS/97/443
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The basic physical processes responsible for X-ray emission from thin plasmas are considered. Collisional ionization or photoionization of inner shells of neutral atoms and ions leads to the creation of a vacancy in one of the inner shells of the ion or atom, which is filled by a cascade of radiative (fluorescent) and nonradiative (Auger) transitions. The net result is the ejection of several electrons and photons, leaving the atom in a multiply ionized state. In this paper, the distribution of the number of emitted photons and electrons after the creation of a hole in an inner shell of an atom or ion is calculated for all ions from H to Zn. The method consists of two stages: the calculation of transition rates for a given electron configuration, and calculation of probabilities of the several cascade sequences using these transition rates.
- ID:
- ivo://CDS.VizieR/J/A+A/376/1106
- Title:
- Forbidden transitions in Co(16+)
- Short Name:
- J/A+A/376/1106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Theoretical line strengths and transition probabilities for electric quadrupole (E2) transitions between levels belonging to several important configurations of Co16+ are reported. The calculations have been carried out with the Relativistic Quantum Defect Orbital (RQDO) method. A general good accord between the present results and some earlier theoretical data is found. Some of the E2 transition probabilities are reported for the first time. The correct systematic behaviour of the RQDO line strengths along the spectral series is reproduced by the present results in the absence of configuration mixing. This semiempirical method appears to adequately describe E2 transitions in this medium-Z atomic system.
- ID:
- ivo://CDS.VizieR/J/MNRAS/449/2438
- Title:
- Formamide detection with ASAI-IRAM
- Short Name:
- J/MNRAS/449/2438
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Formamide (NH_2_CHO) has been proposed as a pre-biotic precursor with a key role in the emergence of life on Earth. While this molecule has been observed in space, most of its detections correspond to high-mass star-forming regions. Motivated by this lack of investigation in the low-mass regime, we searched for formamide, as well as isocyanic acid (HNCO), in 10 low- and intermediate-mass pre-stellar and protostellar objects. The present work is part of the IRAM Large Programme ASAI (Astrochemical Surveys At IRAM), which makes use of unbiased broad-band spectral surveys at millimetre wavelengths. We detected HNCO in all the sources and NH_2_CHO in five of them. We derived their abundances and analysed them together with those reported in the literature for high-mass sources. For those sources with formamide detection, we found a tight and almost linear correlation between HNCO and NH_2_CHO abundances, with their ratio being roughly constant - between 3 and 10 - across 6 orders of magnitude in luminosity. This suggests the two species are chemically related. The sources without formamide detection, which are also the coldest and devoid of hot corinos, fall well off the correlation, displaying a much larger amount of HNCO relative to NH_2_CHO. Our results suggest that, while HNCO can be formed in the gas-phase during the cold stages of star formation, NH_2_CHO forms most efficiently on the mantles of dust grains at these temperatures, where it remains frozen until the temperature rises enough to sublimate the icy grain mantles. We propose hydrogenation of HNCO as a likely formation route leading to NH_2_CHO.
- ID:
- ivo://CDS.VizieR/J/ApJS/194/34
- Title:
- Fourier transform emission spectroscopy of ^13^C^14^N
- Short Name:
- J/ApJS/194/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Emission spectra of the B^2^{Sigma}^+^-X^2^{Sigma}^+^ transition of ^13^C^14^N have been observed at high resolution using the Fourier transform spectrometer associated with the McMath-Pierce Solar Telescope of the National Solar Observatory. The spectra have been measured in the 21000-30000cm^-1^ region and a total of 52 vibrational bands involving vibrational levels up to {nu}=15 of the ground and excited states have been rotationally analyzed to provide a much improved set of spectroscopic constants. An experimental line list and calculated term values are provided. The results of the present analysis should prove useful in the identification of additional ^13^C^14^N lines in comets and cool stars, and will help in the determination of the ^12^C/^13^C abundance ratio.
- ID:
- ivo://CDS.VizieR/J/ApJS/223/12
- Title:
- FTS high resolution of CoIII
- Short Name:
- J/ApJS/223/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The spectrum of CoIII has been recorded in the region 1562-2564{AA} (64000cm^-1^-39000cm^-1^) by Fourier transform (FT) spectroscopy, and in the region 1317-2500{AA} (164000cm^-1^-40000cm^-1^) using a 10.7m grating spectrograph with phosphor image plate detectors. The spectrum was excited in a cobalt-neon Penning discharge lamp. We classified 514 CoIII lines measured using FT spectroscopy, the strongest having wavenumber uncertainties approaching 0.004cm^-1^ (approximately 0.2m{AA} at 2000{AA}, or 1 part in 10^7^), and 240 lines measured with grating spectroscopy with uncertainties between 5 and 10m{AA}. The wavelength calibration of 790 lines of Raassen & Orti Ortin (1984PhyBC.123..353R) and 87 lines from Shenstone (1960CaJPh..38..677S) has been revised and combined with our measurements to optimize the values of all but one of the 288 previously reported energy levels. Order of magnitude reductions in uncertainty for almost two-thirds of the 3d^6^4s and almost half of the 3d^6^4p revised energy levels are obtained. Ritz wavelengths have been calculated for an additional 100 forbidden lines. Eigenvector percentage compositions for the energy levels and predicted oscillator strengths have been calculated using the Cowan code.
