a b s t r a c t The ab initio quasirelativistic Hartree–Fock method developed specifically for the calculation of spectral parameters of heavy atoms and highly charged ions is used to derive transition data for a multicharged tungsten ion. The configuration interaction method is applied to include electron correlation effects. The relativistic effects are taken into account in the Breit–Pauli approximation for quasirelativistic Hartree–Fock radial orbitals. The energy level spectra, radiative lifetimes and Lande gfactors are calculated for the 4p 6 4d 2 , 4p 6 4d4f, and 4p 5 4d 3 configurations of the ion W 36+ . The transition wavelengths, spontaneous transition probabilities, oscillator strengths, and line strengths for the electric dipole, electric quadrupole, electric octupole, and magnetic dipole transitions among the levels of these configurations are tabulated.

Atomic Data and Nuclear Data Tables

We have constructed a comprehensive grid of 680 metal line-blanketed, non-LTE, plane-parallel, hydrostatic model atmospheres for the basic parameters appropriate to O-type stars. The OSTAR2002 grid considers 12 values of effective temperatures, 27; 500 KTeff � 55; 000 K with 2500 K steps, eight surface gravities, 3:0 � log g � 4:75 with 0.25 dex steps, and 10 chemical compositions, from metal-rich relative to the Sun to metal-free. The lower limit of log g for a given effective temperature is set by an approximate location of the Eddington limit. The selected chemical compositions have been chosen to cover a number of typical environments of massive stars: the Galactic center, the Magellanic Clouds, blue compact dwarf galaxies like I Zw 18, and galaxies at high redshifts. The paper contains a description of the OSTAR2002 grid and some illustrative examples and comparisons. The complete OSTAR2002 grid is available on-line. Subject headings: methods: numerical — radiative transfer — stars: atmospheres — stars: early-type

/pdf/a-grid-of-non-lte-line-blanketed-model-atmospheres-of-o-type-537n9ikqss.pdf

A Grid of Non-LTE Line-blanketed Model Atmospheres of O-Type Stars

We have constructed a comprehensive grid of 1540 metal line-blanketed, NLTE, plane-parallel, hydrostatic model atmospheres for the basic parameters appropriate to early B-type stars. The BSTAR2006 grid considers 16 values of effective temperatures, 15,000 K ≤ Teff ≤ 30,000 K with 1000 K steps, 13 surface gravities, 1.75 ≤ log g ≤ 4.75 with 0.25 dex steps, six chemical compositions, and a microturbulent velocity of 2 km s-1. The lower limit of log g for a given effective temperature is set by an approximate location of the Eddington limit. The selected chemical compositions range from twice to one-tenth of the solar metallicity and metal-free. Additional model atmospheres for B supergiants (log g ≤ 3.0) have been calculated with a higher microturbulent velocity (10 km s-1) and a surface composition that is enriched in helium and nitrogen and depleted in carbon. This new grid complements our earlier OSTAR2002 grid of O-type stars (our Paper I). The paper contains a description of the BSTAR2006 grid and some illustrative examples and comparisons. NLTE ionization fractions, bolometric corrections, radiative accelerations, and effective gravities are obtained over the parameter range covered by the grid. By extrapolating radiative accelerations, we have determined an improved estimate of the Eddington limit in absence of rotation between 55,000 and 15,000 K. The complete BSTAR2006 grid is available at the TLUSTY Web site.

http://iopscience.iop.org/article/10.1086/511270/pdf

A Grid of NLTE Line-blanketed Model Atmospheres of Early B-Type Stars

The CHIANTI spectral code consists of two parts: an atomic database and a suite of computer programs in Python and IDL. Together, they allow the calculation of the optically thin spectrum of astrophysical objects and provide spectroscopic plasma diagnostics for the analysis of astrophysical spectra. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, ionization, and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7.1 has been released, which includes improved data for several ions, recombination rates, and element abundances. In particular, it provides a large expansion of the CHIANTI models for key Fe ions from Fe VIII to Fe XIV to improve the predicted emission in the 50-170 A wavelength range. All data and programs are freely available at http://www.chiantidatabase.org and in SolarSoft, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

https://iopscience.iop.org/article/10.1088/0004-637X/763/2/86/pdf

Chianti—an atomic database for emission lines. xiii. soft x-ray improvements and other changes

The CHIANTI spectral code consists of an atomic database and a suite of computer programs to calculate the optically thin spectrum of astrophysical objects and carry out spectroscopic plasma diagnostics. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, and ionization and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7 has been released, which includes several new ions, significant updates to existing ions, as well as Chianti-Py, the implementation of CHIANTI software in the Python programming language. All data and programs are freely available at http://www.chiantidatabase.org, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

/pdf/chianti-an-atomic-database-for-emission-lines-xii-version-7-4y5jdtauvc.pdf

Chianti—an atomic database for emission lines. xii. version 7 of the database

Atomic Spectra Database

A summary of the contents and features of the new NIST Atomic Spectra Database is presented. All material in this large database has been obtained from critical data assessments done over the last 30 years. Only reference data, i.e., data fulfilling certain quality requirements, are included. For each spectral line and energy level, one numerical value—the “best” available value—is tabulated.

NIST Atomic Spectra Database

NIST Atomic Spectroscopic Database (version 1.3)

The new Atomic Spectra Database (ASD), Version 2.0, of the National Institute of Standards and Technology (NIST) contains significantly more data and covers a wider range of atomic and ionic transitions and energy levels than earlier versions. All data are integrated. It also has a new user interface and search engine. ASD contains spectral reference data which have been critically evaluated and compiled by NIST. Version 2.0 contains data on 900 spectra, with about 70000 energy levels and 91000 lines ranging from about 1 Angstrom to 200 micrometers, roughly half of which have transition probabilities with estimated uncertainties. References to the NIST compilations and original data sources are listed in the ASD bibliography. A detailed "Help" file serves as a user's manual, and full search and filter capabilities are provided.

https://iopscience.iop.org/article/10.1238/Physica.Topical.083a00158/pdf

G R. Dalton

Papers

Atomic Spectra Database

NIST Atomic Spectra Database

NIST Atomic Spectroscopic Database (version 1.3)

The New NIST Atomic Spectra Database

NIST Atomic Spectra Database (1998) | NIST