81 citations · 209 across the 7 of their papers we have counts for
7 papers
R-Matrix calculations for opacities: I. Methodology and computations
A. K. Pradhan, S. N. Nahar, W. Eissner
An extended version of the R-matrix methodology is presented for calculation of radiative parameters for improved plasma opacities. Contrast and comparisons with existing methods p…
R-Matrix calculations for opacities.II. Photoionization and oscillator strengths of iron ions FeXVII, FeXVIII and FeXIX
S. N. Nahar, L. Zhao, W. Eissner +1
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…
Converged Close-Coupling R-Matrix calculations of Photoionization of Fe XVII in Astrophysical Plasmas: from Convergence to Completeness
Lianshui Zhao, Werner Eissner, Sultana N. Nahar +1
Extensive resonance structures are manifest in R-Matrix (RM) calculations. However, there exist a large number of highly excited electronic configurations that may contribute to ba…
Improved collision strengths and line ratios for forbidden [O III] far-infrared and optical lines
Ethan Palay, Sultana N. Nahar, Anil K. Pradhan +1
Far-infrared and optical [O III] lines are useful temeprature-density diagnostics of nebular as well as dust obscured astrophysical sources. Fine structure transitions among the gr…
Highly Excited Core Resonances in Photoionization of Fe XVII : Implications for Plasma Opacities
Sultana N. Nahar, Anil K. Pradhan, Guo-Xin Chen +1
A comprehensive study of high-accuracy photoionization cross sections is carried out using the relativistic Breit-Pauli R-matrix (BPRM) method for (hnu + Fe XVII --> Fe XVIII + e).…
[O II] line ratios
Anil K. Pradhan, Maximiliano Montenegro, Sultana N. Nahar +1
Based on new calculations we reconfirm the low and high density limits on the forbidden fine structure line ratio [O II] I(3729)/I(3726): lim_{N_ e} --> 0} = 1.5 and lim_{N_ e} -->…
Breit-Pauli R-matrix calculations for electron impact excitation of Fe XVII: a benchmark study
Guo-Xin Chen, Anil K. Pradhan, W. Eissner
A comprehensive study of relativistic and resonance effects in electron impact excitation of (e+Fe XVII) is carried out using the BPRM method in the relativistic close coupling app…