- ID:
- ivo://CDS.VizieR/J/A+A/399/799
- Title:
- Effective collision strengths for Fe XI trans.
- Short Name:
- J/A+A/399/799
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Collision strengths for transitions among the lowest 48 fine-structure levels belonging to the (1s^2^2s^2^2p^6^) 3s^2^3p^4^, 3s3p^5^, 3s^2^3p^3^3d and 3p^6^ configurations of Fe XI have been calculated using the Dirac Atomic R-matrix Code (DARC) of Norrington & Grant (2003, Comput. Phys. Commun., in prep.). Results are tabulated at energies above thresholds in the range 10<=E<=100Ry, although resonances have been resolved in a fine energy mesh in the thresholds region. Effective collision strengths, obtained after integrating the collision strengths over a Maxwellian distribution of electron velocities, are also tabulated over a wide electron temperature range below 5x10^6^K. Comparisons with other available results are made, and the accuracy of the present data is assessed.
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- ID:
- ivo://CDS.VizieR/J/A+A/439/1215
- Title:
- Effective collision strengths for Fe X trans.
- Short Name:
- J/A+A/439/1215
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Collision strengths for 4005 transitions among the lowest 90 levels of the (1s^2^2s^2^2p^6^) 3s^2^3p^5^, 3s3p^6^, 3s^2^3p^4^3d, 3s3p^5^3d and 3s^2^3p^3^3d^2^ configurations of Fe X have been calculated using the Dirac Atomic R-matrix Code (DARC) of Norrington & Grant (2005, Comput. Phys. Commun. , in prep.), over a wide energy range up to 210Ryd. Resonances have been resolved in the threshold region, and effective collision strengths have been obtained over a wide temperature range up to 10^7^K. The present calculations should represent a significant improvement (in both range and accuracy) over the earlier available results of Bhatia & Doschek (1995, At. Data Nucl. Data Tables, 60, 97), Tayal (2001ApJS..132..117T) and Pelan & Berrington (2001A&A...365..258P). Based on several comparisons, the accuracy of our data is assessed to be better than 20%, for a majority of transitions.
- ID:
- ivo://CDS.VizieR/J/A+A/510/A79
- Title:
- Effective collision strengths for K II
- Short Name:
- J/A+A/510/A79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Oscillator strengths and electron impact excitation collision strengths for transitions between the 43 fine-structure levels of the 3p^6^, 3p^5^ 4s, 3p^5^ 3d, 3p^5^ 4p, 3p^5^ 4d and 3p^5^ 5s configurations in KII are calculated. Thermally averaged collision strengths are presented as a function of electron temperature for application to astrophysical plasmas.
- ID:
- ivo://CDS.VizieR/J/A+AS/125/543
- Title:
- Effective collision strengths for Mg VI
- Short Name:
- J/A+AS/125/543
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The effective collision strengths are presented in this table for all transitions among the lowest 23 fine-structure levels of Mg VI. Each fine-structure level is assigned an index number in Table 3 of the manuscript ranging from 1 to 23. These index values are reproduced here in Table 5 to depict a particular transition. eg. Index 1-3 denotes the transition 2s(2)2p(3)4SO(3/2)-2s(2)2p(3)2DO(5/2) The effective collision strengths for each transition are presented in rows for a number of electron temperatures ranging from log(T)=5.0 to log(T)=6.1. A superscript indicates the power of 10 by which the number should be multiplied.
- ID:
- ivo://CDS.VizieR/J/ApJ/850/147
- Title:
- Effective collision strengths for OIII transitions
- Short Name:
- J/ApJ/850/147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Transition probabilities, electron excitation collision strengths, and rate coefficients for a large number of OIII lines over a broad wavelength range, from the infrared to ultraviolet, have been reported. The collision strengths have been calculated in the close-coupling approximation using the B-spline Breit-Pauli R-matrix method. The multiconfiguration Hartree-Fock method in combination with B-spline expansions is employed for an accurate representation of the target wave functions. The close-coupling expansion contains 202 O^2+^ fine-structure levels of the 2s^2^2p^2^, 2s2p^3^, 2p^4^, 2s^2^2p3s, 3p, 3d, 4s, 4p, 4d, 4f, 5s, and 2s2p^3^3s, 3p, 3d configurations. The effective collision strengths are obtained by averaging electron excitation collision strengths over a Maxwellian distribution of velocities at electron temperatures ranging from 100 to 100000K. The calculated effective collision strengths have been reported for the 20302 transitions between all 202 fine-structure levels. There is an overall good agreement with the recent R-matrix calculations by Storey+ (2014, VI/141) for the transitions between all levels of the ground 2s^2^2p^2^ configuration, but significant discrepancies have been found with Palay et al. for transitions to the 2s^2^2p^2^ ^1^S_0_ level. Line intensity ratios between the optical lines arising from the 2s^2^2p^2^ ^3^P_0,1,2_ - ^1^D_2_ transitions have been compared with other calculations and observations from the photoionized gaseous nebulae, and good agreement is found. The present calculations provide the most complete and accurate data sets, which should allow a more detailed treatment of the available measured spectra from different ground and space observatories.
- ID:
- ivo://CDS.VizieR/J/A+A/410/349
- Title:
- Effective collision strengths in Fe XV
- Short Name:
- J/A+A/410/349
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Collision strengths for transitions among the energetically lowest 53 fine-structure levels belonging to the (1s^2^ 2s^2^ 2p^6^) 3l^2^, 3l3l', 3s4l and 3p4s configurations of Fe XV are computed, over an electron energy range below 160Ryd, using the Dirac Atomic R-matrix Code (DARC) of Norrington & Grant (2003, Comput. Phys. Commun., in prep.). Effective collision strengths, obtained after integrating the collision strengths over a Maxwellian distribution of electron energies, have also been calculated. These results of effective collision strengths are tabulated for all 1378 inelastic transitions over a wide temperature range of 10^5^ to 10^7^K. Comparisons are also made with other R-matrix calculations and the accuracy of the results is assessed.
- ID:
- ivo://CDS.VizieR/J/ApJ/738/5
- Title:
- Effective collision strengths in NiII
- Short Name:
- J/ApJ/738/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present collision strengths and Maxwellian averaged effective collision strengths for the electron-impact excitation of NiII. Attention is expressly concentrated on the optically allowed fine-structure transitions between the 3d^9^, 3d^8^4s, and 3d^7^4s^2^ even parity levels and the 3d^8^4p and 3d^7^4s 4p odd parity levels. The parallel RMATRXII R-matrix package has been recently extended to allow for the inclusion of relativistic fine-structure effects. This suite of codes has been utilized in conjunction with the parallel PSTGF and PSTGICF programs in order to compute converged total collision strengths for the allowed transitions with which this study is concerned. All 113 LS terms identified with the 3d^9^, 3d^8^4s, 3d^7^4s^2^, 3d^8^4p, and 3d^7^4s 4p basis configurations were included in the target wavefunction representation, giving rise to a sophisticated 295 jj-level, 1930 coupled channel scattering complex. Maxwellian averaged effective collision strengths have been computed at 30 individual electron temperatures ranging from 30 to 1000000K. This range comfortably encompasses all temperatures significant to astrophysical and plasma applications.
- ID:
- ivo://CDS.VizieR/J/A+A/524/A35
- Title:
- Effective collision strengths of CrII
- Short Name:
- J/A+A/524/A35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Absorption or emission lines of Cr II are observed in a wide variety of astrophysical spectra and accurate atomic data are urgently needed to interpret these lines. Many of these data are impossible to measure experimentally and a full theoretical treatment is the only means by which these data can be obtained.
- ID:
- ivo://CDS.VizieR/J/ApJ/743/206
- Title:
- Effective collision strengths of FeVIII
- Short Name:
- J/ApJ/743/206
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New extensive calculations are reported for electron collision strengths, rate coefficients, and transition probabilities for the astrophysically important lines of FeVIII. The collision strengths have been calculated in the close-coupling approximation using the B-spline Breit-Pauli R-matrix method (BSR) code (Zatsarinny 2006CoPhC.174..273Z). The multiconfiguration Hartree-Fock method with term-dependent non-orthogonal orbitals is employed for an accurate representation of the target wave functions. The close-coupling expansion includes 102 fine-structure levels of FeVIII covering all possible terms of the ground 3p^6^3d and singly excited 3p^5^3d^2^, 3p^6^4l, 3p^5^3d4s, 3s3p^6^3d^2^, and 3p^6^5l configurations. The present calculations are more extensive than the previous ones, leading to a total 5151 transitions between fine-structure levels. The effective collision strengths are obtained by averaging the electron collision strengths over a Maxwellian distribution of velocities and these are tabulated for all fine-structure transitions at electron temperatures in the range from 5x10^3^ to 5x10^6^K. There is an overall good agreement with the previous 77-state calculations by Griffin, Pindzola, & Badnell (2000A&AS..142..317G), but significant differences are also noted for some transitions.
- ID:
- ivo://CDS.VizieR/J/A+A/513/A55
- Title:
- Effective collision strengths of Ni II
- Short Name:
- J/A+A/513/A55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Considerable demand exists for electron excitation data for Ni II, since lines from this abundant ion are observed in a wide variety of laboratory and astrophysical spectra. The accurate theoretical determination of these data can present a significant challenge however, due to complications arising from the presence of an open 3d-shell in the description of the target ion.