Resonance and intersystem transition lines of astrophysical importance in neutral sulfur

Abstract

A systematic study of S I levels belonging to 3s23p4, 3s3p5, 3s23p3(4So, 2Do, 2Po)nℓ, where nℓ = 4s, 5s, 6s, 4p, 5p, 6p, 3d, 4d, 5d, 4f and 5f configurations and optically allowed and intersystem transitions among them are presented. A very large set of basis functions are generated using up to three electron promotions from the ground configurations for each of the 24 symmetries considered belonging to two parities. Many of the levels are reported for the first time. Relativistic effects are included through the Breit–Pauli Hamiltonian. The resulting fine-structure levels and oscillator strengths for some astrophysically important transitions are then presented and compared with the available measured and calculated values. Excellent agreement between the present lifetimes and the measurement of Berzinsh et al (1997 Phys. Rev. A 55 1836) and Beideck et al (1994 Astrophys. J. 428 393) are achieved for the 3s23p3(4So)ns(3S1o), 4 ⩽ n ⩽ 6, 3s23p3(4So)4p(3P0,1,2o) and 3s23p3(2Po)4s(3P0,1,2o) levels, respectively.

Atomic Data Revisions for Transitions Relevant to Observations of Interstellar, Circumgalactic, and Intergalactic Matter

“…As in Deb & Hibbert (2006), the data from Deb & Hibbert (2008) agree very well with most lines from the results of the B-spline calculations by Zatsarinny & Bartschat (2006). They are also close to the data produced by Froese .…”

Oscillator strengths and radiative rates for transitions in neutral sulfur

“…We have checked numerous other transitions (strong as well as weak) in the two calculations and found very good agreement. Some of the weaker intercombination transitions are also presented by Deb and Hibbert [29], finding excellent agreement between the two calculations. There is no reason for the two entirely different calculations to produce such an excellent level of agreement unless both are very accurate.…”

“…Prior to presenting our main set of data, we make some comparisons with other work. A few of these transitions, but only those from the ground configuration, were already presented by Deb and Hibbert [29], and compared with other calculations.…”

“…We have optimized a further 23 orbitals.The n' ¼ 4s; 5s; 6s; 4p; 5p; 6p; 3d; 4d; 5d; 4f; 5f orbitals are taken as spectroscopic and the remaining 7s; 8s; 9s; 7p; 8p; 9p; 6d; 7d; 8d; 9d; 6f; 5g functions are optimized as either a correction or a correlation orbital.It is important to take a balanced account of correction and correlation effects for all the spectroscopic orbitals considered in the calculation.The 4s; 5s; and 6s orbitals are optimized on the energies of the corresponding 5 S o states, 7s and 8s are taken as corrections to 4s and 5s states, respectively, while 9s is taken as being of correlation type and optimized on ð3s 2 3p 4 þ 3s 2 3p 2 ns msÞ 3 P , 4 6 n; m 6 9.The 4p; 5p; and 6p orbitals are optimized on the energies of the respective 3 P states, 7p and 8p are optimized as the correction to 5p level, and 9p is taken as the correlation orbital and is optimized on the energies of ð3s 2 3p 4 þ 3p 6 þ 3s 2 3p 2 npmpÞ 1 S, 4 6 n; m 6 9.The 3d orbital is optimized on3p 3 ð 4 S o Þ3d 5 D o ; 4d is optimized on the lowest of 3p 3 ð 4 S o ; 2 D o ; 2 P o Þ4d 3 D o ; 5d; 7d; 8d; and 9d are taken as correction orbitals, while 6d is taken as correlation type and optimized on the energies of ð3s 2 3p 4 þ 3s3p 4 ndÞ 3 P , 3 6 n 6 6; 4f; and 5f are optimized on corresponding 5 F states; 6f is again taken as being of correlation type and optimized on ð3s 2 3p 4 þ 3s 2 3p 3 ð 2 D o ÞnfÞ 3 P , 4 6 n 6 6; and finally 5g is optimized on the energy of the real 3s 2 3p 3 ð 4 S o Þ5g 5 G o state. The parameters for all the optimized orbitals are presented by Deb and Hibbert [29].…”

“…(1) are generated by allowing all one-, two-, and some three-electron promotions from a basic reference set to the orbitals available to us. This would lead to nearly a million CSFs [29] belonging to 24 symmetries within odd and even parities. We are able to determine the LS energies of 114 states, 61 of which are previously unreported.…”