相关论文: The Iron Project

Latest developments in theoretical computations since the international Opacity Project (OP), under the new the Iron Project (IP) and extensions, are described for applications to a variety of objects such as stellar atmospheres, nebulae,…

The IRON Project, initiated in 1991, aims at two main objectives, i) study the characteristics of and calculate large-scale high accuracy data for atomic radiative and collisional processes, and ii) application in solving astrophysical…

The Breit-Pauli R-matrix method developed under the Iron Project has been used to obtain extensive sets of oscillator strengths and transition probabilities for dipole allowed and intercombination fine structure transitions in carbon like…

Relativistic atomic structure calculations for electric dipole E1, electric quadrupole E2 and magnetic dipole M1 transition probabilities among the first 80 fine-structure levels of Fe VI, dominated by configurations 3d^3, 3d^24s, and…

A hot central star illuminating the surrounding ionized H II region usually produces very rich atomic spectra resulting from basic atomic processes: photoionization, electron-ion recombination, bound-bound radiative transitions, and…

The Opacity Project (OP) and Iron Project (IP) are pioneering international collaborations which have been computing, for more than 25 years, massive atomic data sets for astrophysical applications. We review the data activities that have…

We present new atomic data (radiative transitions rates and collision strengths) from large scale calculations and a non-LTE spectral model for Fe III. This model is in very good agreement with observed astronomical emission spectra, in…

We present new calculations for transition probabilities of Fe IV, with much more extensive datasets than heretofore available. The large-scale close coupling R-matrix calculations yield 1,798 LS bound states with n $\leq$ 11 and $l \leq$…

State-of-the-art NLTE model-atmosphere codes have arrived at a high level of numerical sophistication and are now useful tools to analyze high-quality spectra from the infrared to the X-ray wavelength range. The capacity of current…

An extensive set of dipole-allowed, intercombination, and forbidden transition probabilities for Fe V is presented. The Breit-Pauli R-matrix (BPRM) method is used to calculate 1.46 x 10^6 oscillator strengths for the allowed and…

A general formulation is employed to study and quantitatively ascertain the effect of plasma broadening of {\it intrinsic} autoionizing (AI) resonances in photoionization cross sections. In particular, R-matrix data for iron ions described…

Opacity determines radiation transport through material media. In a plasma source the primary contributors to atomic opacity are bound-bound line transitions and bound-free photoionization into the continuum. We review the theoretical…

Iron is the dominant heavy element that plays an important role in radiation transport in stellar interiors. Owing to its abundance and large number of bound levels and transitions, iron ions determine the opacity more than any other…

Systematic R-matrix calculations of electron-impact excitation for ions of astrophysical interest have been performed since 2007 for many iso-electronic sequences as part of the UK Atomic Process for Astrophysical Plasma (APAP) network.…

Nowadays, several opacity codes are able to provide data for stellar structure models, but the computed opacities may show significant differences. In this work, we present state-of-the-art precise spectral opacity calculations, illustrated…

We discuss recent improvements in the calculation of the radiative cooling in both collisionally and photo ionized plasmas. We are extending the spectral simulation code Cloudy so that as much as possible of the underlying atomic data is…

Relativistically broadened and redshifted 6.4 -- 6.9 keV iron K lines are observed from many accretion powered objects, including X-ray binaries and active galactic nuclei (AGN). Existence of gas close to the central engine implies large…

This work reports radiative transition rates and electron impact excitation rate coefficients for levels of the n= 3, 4, 5, 6, 7, 8 configurations of Ca II. The radiative data were computed using the Thomas-Fermi-Dirac central potential…

Relativistic and resonance effects in the photoionization of Mg-like Fe~XV are investigated using the Breit-Pauli R-matrix Method (BPRM) at near-threshold and intermediate energies, complemented by the Relativistic Random Phase…

We present extensive tables of the Atomic Partition Function for iron ions, Fe I -- Fe X, and discuss details of the computational method. Partition functions are given in wide range of temperatures, 10^3 K < T < 10^6 K, and lowering of…