中文
相关论文

相关论文: Atomic data for neutron-capture elements I. Photoi…

200 篇论文

We present multi-configuration Breit-Pauli distorted-wave photoionization (PI) cross sections and radiative recombination (RR) and dielectronic recombination (DR) rate coefficients for the first six krypton ions. These were calculated with…

太阳与恒星天体物理 · 物理学 2015-05-28 N. C. Sterling

[Abridged] Investigations of neutron(n)-capture element nucleosynthesis and chemical evolution have largely been based on stellar spectroscopy. However, the recent detection of these elements in several planetary nebulae (PNe) indicates…

The detection of neutron(n)-capture elements in several planetary nebulae (PNe) has provided a new means of investigating s-process nucleosynthesis in low-mass stars. However, a lack of atomic data has inhibited accurate trans-iron element…

太阳与恒星天体物理 · 物理学 2015-06-17 N. C. Sterling , R. L. Porter , H. L. Dinerstein

Dielectronic recombination (DR) is the dominant recombination process for most heavy elements in photoionized clouds. Accurate DR rates for a species can be predicted when the positions of autoionizing states are known. Unfortunately such…

星系天体物理 · 物理学 2015-05-20 N. R. Badnell , G. J. Ferland , T. W. Gorczyca , D. Nikolic , G. A. Wagle

Neutron(n)-capture elements (atomic number Z>30), which can be produced in planetary nebula (PN) progenitor stars via s-process nucleosynthesis, have been detected in nearly 100 PNe. This demonstrates that nebular spectroscopy is a…

太阳与恒星天体物理 · 物理学 2015-05-30 N. C. Sterling , M. C. Witthoeft , D. A. Esteves , P. C. Stancil , A. L. D. Kilcoyne , R. C. Bilodeau , A. Aguilar

We have carried-out multi-configuration Breit-Pauli AUTOSTRUCTURE calculations for the dielectronic recombination (DR) of Fe^{8+} - Fe^{12+} ions. We obtain total DR rate coefficients for the initial ground-level which are an order of…

天体物理学 · 物理学 2010-11-11 N. R. Badnell

Aimed at ionization balance and spectral analysis of UV and X-ray sources, we present self-consistent sets of photoionization cross sections, recombination cross sections, and rate coefficients for Li-like O VI and He-like O VII.…

天体物理学 · 物理学 2009-11-07 Sultana N. Nahar , Anil K. Pradhan

We have conducted a large-scale survey of 120 planetary nebulae (PNe) to search for the near-infrared emission lines [Kr III] 2.199 and [Se IV] 2.287 microns. The neutron(n)-capture elements Se and Kr may be enriched in a PN if its…

天体物理学 · 物理学 2007-05-23 N. C. Sterling , Harriet L. Dinerstein , T. R. Kallman

The first complete set of unified cross sections and rate coefficients are calculated for photoionization and recombination of He- and Li-like ions using the relativistic Breit-Pauli R-matrix method. We present total, unified (e + ion)…

天体物理学 · 物理学 2016-08-30 Sultana N. Nahar , Anil K. Pradhan , Hong Lin Zhang

Photoionization and recombination cross sections and rate coefficients are calculated for Li-like Fe XXIV and He-like Fe XXV using the Breit-Pauli R-matrix (BPRM) method. A complete set of total and level-specific parameters is obtained to…

天体物理学 · 物理学 2009-10-31 Sultana N. Nahar , Anil K. Pradhan , Hong Lin Zhang

Here we report new ${\it ab initio}$ calculations of the effective recombination coefficients for the \ion{N}{ii} recombination spectrum. We have taken into account the density dependence of the coefficients arising from the relative…

太阳与恒星天体物理 · 物理学 2015-05-27 X. Fang , P. J. Storey , X. -W. Liu

We present a theoretical investigation of dielectronic recombination (DR) of Ar-like ions that sheds new light on the behavior of the rate coefficient at low-temperatures where these ions form in photoionized plasmas. We provide results for…

原子物理 · 物理学 2013-03-13 D. Nikolić , T. W. Gorczyca , K. T. Korista , N. R. Badnell

Photoionization cross sections and recombination rate coefficients are presented for the L-shell ground state fine structure levels $2s^22p^4 \ ^3P_{2,0,1}$ of Fe~XIX. Several sets of calculations including relativistic effects are carried…

天体物理学 · 物理学 2009-10-31 Hong Lin Zhang , Anil K. Pradhan

Ar XIII is found to be unique with new features in electron-ion recombination not seen in any other ion. The ion has been studied with the unified method which provides a theoretically self-consistent set of atomic parameters for the…

天体物理学 · 物理学 2009-11-10 Sultana N. Nahar

Theoretically self-consistent calculations for photoionization and (e + ion) recombination are described. An identical eigenfunction expansion for the ion is employed in coupled channel calculations for both processes, thus ensuring…

天体物理学 · 物理学 2007-05-23 Sultana N. Nahar

We present the first detailed ab initio quantum mechanical calculations for total and state-specific recombination rate coefficients for e + Ni III --> Ni II. These rates are obtained using a unified treatment for total electron-ion…

天体物理学 · 物理学 2009-11-06 Sultana N. Nahar , Manuel A. Bautista

The inverse processes of photoionization and electron-ion recombination of (hnu + Ni XXVI --> Ni XXVII + e and (hnu + Ni XXVII --> Ni XXVIII + e) are studied using the unified method for the total recombination. The method subsumes both the…

天体物理学 · 物理学 2009-11-10 Sultana N. Nahar

For photoionized plasmas, electron energy-loss rates due to radiative recombination (RR) are required for thermal equilib- rium calculations, which assume a local balance between the energy gain and loss. While many calculations of total…

高能天体物理现象 · 物理学 2017-02-22 Junjie Mao , Jelle Kaastra , N. R. Badnell

Relativistic and channel coupling effects in photoionization and unified electronic recombination of Fe XVII are demonstrated with an extensive 60-level close coupling calculation using the Breit-Pauli R-matrix method. Photoionization and…

天体物理学 · 物理学 2009-11-06 Hong Lin Zhang , Sultana N. Nahar , Anil K. Pradhan

We present total and final-state resolved charge transfer (CT) rate coefficients for low-charge Ge, Se, Br, Kr, Rb, and Xe ions reacting with neutral hydrogen over the temperature range 10^2--10^6 K. Each of these elements has been detected…

太阳与恒星天体物理 · 物理学 2015-05-30 N. C. Sterling , P. C. Stancil
‹ 上一页 1 2 3 10 下一页 ›