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Up: Radiative transition probabilities

3. Transition probabilities

The transition probabilities, Aki, were calculated for magnetic dipole (M1) and electric quadrupole (E2) lines connecting the 47 energetically lowest levels belonging to the 3d8, 3d74s and 3d64s2 configurations of Co II, i.e. the transitions in which both energy levels are below the lowest level of odd parity.

Table 3 (click here) contains the experimental wavelengths deduced from the observed energy levels (Sugar & Corliss 1985) and the A-values calculated in the present work. All the calculations were carried out using the computed energy intervals but the use of experimental energy differences would only produce a marginal change in the final results. If the two types of radiation (M1 and E2) contribute significantly to the total intensity of a line, the sum of both components is given. The exclusion criterion of one particular type of radiation for a given transition is that the corresponding A-value should be less than 1% of the sum of M1 and E2 contributions. Owing to the extensive nature of the results, only transitions for which Aki is greater than 0.001 s-1 are reported in the table. The complete data can be obtained upon request to the author.

As already noticed for other ions, examining the results, it is seen that for most of the strong multiplets either magnetic dipole radiation predominates (electric quadrupole radiation being negligible) or electric quadrupole radiation predominates (magnetic dipole radiation being negligible). In the former case, the transitions are mostly intercombination multiplets (tex2html_wrap_inline1365S tex2html_wrap_inline1553 0) made possible by spin-orbit interaction. In the latter case, the transitions are mostly allowed by the LS-coupling selection rules for electric quadrupole radiation (i.e. tex2html_wrap_inline1365S = 0, tex2html_wrap_inline1365L = 0, tex2html_wrap_inline15651, tex2html_wrap_inline15652). There are few transitions in which the two types of radiation are of comparable intensities.

 

Multiplet J-J' tex2html_wrap_inline1591(Å)a Type Aki
a3F-a3F 4-3 105178.00 M1 2.21(-2)
3-2 154562.77 M1 9.88(-3)
a3F-b3F 4-4 10187.81 E2 5.36(-2)
4-3 9335.84 E2 2.30(-2)
4-2 8829.97 E2 1.01(-3)
3-4 11280.47 E2 6.33(-3)
3-3 10245.24 E2 3.47(-2)
3-2 9639.21 M1,E2 3.16(-2)
2-3 10972.56 E2 8.74(-3)
2-2 10280.34 M1,E2 4.06(-2)
a3F-a1D 4-2 8580.24 E2 9.74(-3)
3-2 9342.38 M1 1.74(-1)
2-2 9943.41 M1,E2 8.16(-2)
a3F-a3P 4-2 7538.96 E2 4.98(-2)
3-2 8121.07 M1,E2 6.70(-2)
3-1 8027.36 E2 4.20(-2)
2-2 8571.44 M1,E2 1.63(-2)
2-1 8467.11 M1,E2 1.68(-2)
2-0 8333.82 E2 5.34(-2)
a3F-a5P 4-2 5544.26 E2 3.42(-3)
3-1 5749.40 E2 1.13(-3)
a3F-a1G 4-4 5209.57 M1 1.36(-1)
3-4 5481.05 M1,E2 7.03(-2)
a3F-a3G 4-5 4623.06 E2 7.73(-1)
4-4 4542.23 E2 1.22(-1)
4-3 4460.13 E2 6.87(-3)
3-5 4835.61 E2 3.33(-2)
3-4 4747.24 E2 5.61(-1)
3-3 4657.64 E2 1.49(-1)
2-4 4897.68 E2 3.76(-2)
2-3 4802.36 E2 5.31(-1)
a3F-b3P 4-2 4152.58 E2 3.12(+0)
3-2 4323.28 E2 5.12(-1)
3-1 4287.50 E2 9.37(-1)
2-2 4447.69 E2 4.72(-2)
2-1 4409.83 E2 5.47(-1)
2-0 4382.03 E2 8.77(-1)
a3F-c3P 4-2 4017.10 E2 2.66(-1)
3-1 4102.73 E2 2.03(+0)
2-2 4292.62 E2 4.32(-3)
2-1 4214.61 E2 3.97(-1)
2-0 4120.12 E2 3.10(+0)
a3F-b1G 4-4 3975.43 M1,E2 2.07(-2)
3-4 4131.60 M1,E2 4.99(-3)*
2-4 4245.08 E2 1.04(-1)
a3F-a3H 4-6 3688.18 E2 2.66(+0)
4-5 3639.41 E2 1.42(-1)
4-4 3582.90 M1,E2 6.10(-3)
3-5 3769.86 E2 2.23(+0)
3-4 3709.26 E2 1.86(-1)
2-4 3800.47 E2 1.93(+0)
Table 3: Radiative transition probabilities, Aki in s-1, as calculated in the present work for forbidden lines of Co II. A(B) stands for A.10B. Only transitions for which Aki is greater than 0.001 s-1 are reported  

 

Multiplet J-J' tex2html_wrap_inline1591(Å)a Type Aki
a3F-a3D 4-3 3637.36 E2 1.59(+0)
4-2 3556.18 E2 8.62(-2)
3-3 3767.66 E2 4.60(-1)
3-2 3680.63 E2 1.26(+0)
3-1 3530.26 E2 2.88(-2)
2-3 3861.80 E2 4.54(-2)
2-2 3770.42 E2 6.30(-1)
2-1 3612.78 E2 8.77(-1)
a3F-a1P 3-1 3753.42 E2 2.64(-1)
2-1 3846.84 E2 7.53(-1)
a3F-a1H 3-5 3375.49 E2 5.52(-2)
a3F-b1D 3-2 3304.94 M1,E2 1.60(-2)
2-2 3377.16 M1,E2 5.60(-3)*
a3F-a5D 4-4 2456.52 M1,E2 2.53(-2)*
4-3 2419.74 M1,E2 1.76(-3)
3-4 2515.28 M1,E2 5.70(-3)
3-3 2476.73 M1,E2 1.83(-3)
a3F-c3F 4-2 2451.97 E2 5.88(-2)
4-3 2445.48 E2 8.87(-1)
4-4 2435.49 E2 2.92(+0)
3-2 2510.51 E2 1.08(+0)
3-3 2503.70 E2 1.80(+0)
3-4 2493.23 E2 6.84(-1)
2-2 2551.96 E2 2.18(+0)
2-3 2544.92 E2 8.00(-1)
2-4 2534.11 E2 3.04(-2)
a3F-a1F 4-3 2267.34 E2 1.83(-2)
3-3 2317.30 E2 1.59(-2)
2-3 2352.57 E2 2.14(-2)
a5F-a5F 5-4 147361.14 M1 1.03(-2)
4-3 187985.83 M1 9.27(-3)
3-2 256741.94 M1 5.00(-3)
2-1 392635.09 M1 1.57(-3)
a5F-b3F 5-4 15469.95 M1 2.66(-2)
4-4 17284.47 M1 2.98(-3)*
4-3 14967.16 M1 4.17(-3)
3-4 19034.62 M1 4.81(-3)
3-3 16261.91 M1 4.53(-3)*
2-3 17361.59 M1 9.59(-3)
2-2 15689.96 M1 4.34(-3)
1-2 16343.04 M1 1.34(-2)
a5F-a5P 5-3 6932.36 E2 3.74(-2)
4-3 7274.58 M1,E2 1.14(-2)
4-2 7139.54 E2 2.10(-2)
3-3 7567.42 M1,E2 2.61(-3)
3-2 7421.40 E2 1.46(-2)
3-1 7255.95 E2 1.10(-2)
2-2 7642.31 E2 6.10(-3)
2-1 7466.98 E2 1.59(-2)
1-2 7794.01 M1,E2 1.30(-3)
1-1 7611.74 E2 1.30(-2)
a5F-a3G 5-5 5470.72 M1 3.73(-1)*
5-4 5357.89 M1 2.17(-2)
4-5 5681.65 M1 7.54(-2)
4-4 5560.05 M1 2.11(-1)
4-3 5437.53 M1 1.37(-2)
3-4 5729.51 M1 9.24(-2)
3-3 5599.50 M1 8.43(-2)
2-3 5724.35 M1 6.46(-2)
Table 3: continued

 

Multiplet J-J' tex2html_wrap_inline1591(Å)a Type Aki
a5F-b3P 3-2 5123.15 M1,E2 9.18(-3)
2-2 5227.47 M1,E2 1.33(-3)*
2-1 5175.25 M1,E2 2.97(-3)
1-2 5298.00 M1 1.15(-3)
1-1 5244.37 M1,E2 1.60(-3)
a5F-c3P 3-2 4918.49 M1,E2 3.98(-2)
2-2 5014.56 M1,E2 5.30(-3)*
2-1 4908.42 M1 3.63(-2)
1-2 5079.43 M1,E2 4.60(-3)
1-1 4970.56 M1,E2 2.57(-2)
a5F-a3H 5-5 4145.02 M1,E2 2.05((-3)
4-5 4264.99 M1,E2 1.03(-3)
4-4 4187.59 M1,E2 1.08(-3)*
a5F-a5D 5-4 2676.94 E2 1.42(+1)
5-3 2633.32 E2 6.64(+0)
4-4 2726.47 E2 5.61(+0)
4-3 2681.23 E2 4.99(+0)
4-2 2651.08 E2 1.06(+1)
3-4 2766.60 E2 1.12(+0)
3-3 2720.03 E2 7.14(+0)
3-2 2689.00 E2 9.22(-1)
3-1 2669.57 E2 1.34(+1)
2-4 2796.74 E2 9.24(-2)
2-3 2749.16 E2 2.49(+0)
2-2 2717.47 E2 6.70(+0)
1-3 2768.55 E2 2.30(-1)
1-2 2736.41 E2 3.42(+0)
1-1 2716.29 E2 8.27(+0)
a5F-a3D 4-3 4262.17 M1 5.36(-1)
3-3 4361.05 M1 1.20(-2)
3-2 4244.86 M1 6.98(-1)
2-3 4436.41 M1 2.53(-2)
2-2 4316.23 M1 6.10(-2)*
2-1 4110.89 M1 3.02(-1)
1-2 4364.21 M1 6.34(-2)
1-1 4154.39 M1 1.41(-1)
a5F-a1P 2-1 4416.68 M1 3.60(-1)
1-1 4466.92 M1 1.65(-1)
a5F-b1D 3-2 3752.87 M1 5.90(-3)
a5F-c3F 5-3 2663.82 E2 1.94(-3)
5-4 2651.98 M1,E2 2.67(-1)
4-3 2712.87 M1,E2 3.87(-2)
4-4 2700.58 M1,E2 7.94(-2)*
3-2 2760.83 M1 5.86(-3)
3-3 2752.59 M1,E2 3.30(-2)*
3-4 2739.95 M1,E2 2.93(-2)
2-2 2790.84 M1 3.02(-2)
2-3 2782.43 M1,E2 6.37(-2)
1-2 2810.82 M1,E2 1.03(-1)
1-3 2802.29 E2 1.28(-3)
b3F-b3F 4-3 111637.78 M1 1.67(-2)
3-2 162957.42 M1 7.26(-3)
b3F-a1G 4-4 10661.30 M1 6.89(-3)
3-4 11786.95 M1 2.82(-3)
b3F-a3G 4-5 8463.87 M1 3.57(-2)
4-4 8196.81 M1 4.33(-2)*
4-3 7933.29 M1 3.06(-3)
3-3 8540.19 M1 3.79(-2)
2-3 9012.51 M1 2.27(-2)
Table 3: continued

 

Multiplet J-J' tex2html_wrap_inline1591(Å)a Type Aki
b3F-b3P 4-2 7009.88 E2 3.02(-2)
3-2 7479.54 E2 5.74(-3)
3-1 7373.09 E2 3.04(-2)
2-1 7722.50 M1,E2 2.30(-2)
2-0 7637.67 E2 2.74(-2)
b3F-c3P 4-2 6632.28 E2 2.04(-2)
3-2 7051.19 M1,E2 1.03(-2)
2-2 7370.09 M1 1.63(-2)
2-1 7143.09 M1,E2 4.37(-3)
2-0 6875.85 E2 1.53(-3)
b3F-b1G 4-4 6519.48 M1 1.84(-1)
3-4 6923.83 M1 1.06(-1)
2-4 7231.07 E2 2.48(-3)
b3F-a3H 4-4 5526.56 M1 7.44(-3)*
3-4 5814.40 M1 3.87(-3)
b3F-a3D 4-3 5657.21 M1 1.07(-1)
3-3 5959.20 M1 6.24(-2)*
3-2 5744.35 M1 8.88(-3)
3-1 5386.29 E2 2.25(-3)
2-3 6185.39 M1,E2 7.66(-3)
2-2 5954.24 M1 3.44(-2)
2-1 5570.41 M1,E2 4.43(-2)
b3F-a1P 3-1 5923.64 E2 3.83(-3)
2-1 6147.09 M1,E2 3.00(-2)
b3F-b1D 3-2 4878.82 M1 5.38(-1)
2-2 5029.40 M1,E2 3.12(-1)
b3F-a5D 4-3 3173.56 E2 6.70(-3)
3-3 3266.42 M1,E2 1.06(-3)*
3-2 3221.78 E2 4.44(-3)
2-2 3286.76 M1,E2 1.45(-3)
2-1 3257.78 M1,E2 2.62(-3)
b3F-c3F 4-3 3217.97 M1,E2 1.59(-2)
4-4 3200.70 M1,E2 3.24(-3)*
3-2 3325.43 M1,E2 2.18(-2)
3-3 3313.49 E2 2.29(-3)
3-4 3295.18 M1 2.00(-2)
2-3 3382.27 M1,E2 2.43(-2)
2-4 3363.19 E2 1.21(-2)
b3F-a1F 3-3 2994.71 M1 9.77(-3)*
2-3 3050.78 M1,E2 1.69(-1)
a1D-a3P 2-2 62122.27 M1 2.96(-2)
2-1 57029.52 M1 2.55(-2)
a1D-a1G 2-4 13261.38 E2 1.80(-3)
a1D-b3P 2-2 8047.29 M1,E2 8.56(-3)*
2-1 7924.21 E2 5.20(-2)
2-0 7834.91 E2 6.39(-2)
a1D-c3P 2-2 7553.59 M1,E2 2.68(-2)*
2-1 7315.32 M1,E2 7.23(-3)*
2-0 7035.30 E2 1.18(-3)
a1D-b1G 2-4 7407.62 E2 7.14(-2)
a1D-a3H 2-4 6151.81 E2 1.44(-2)
a1D-a3D 2-3 6314.12 M1,E2 6.24(-3)
2-2 6073.44 M1,E2 3.92(-3)*
2-1 5674.60 E2 3.29(-1)
a1D-a1P 2-1 6274.22 E2 1.67(-1)
a1D-b1D 2-2 5114.18 M1,E2 9.88(-1)
a1D-a5D 2-4 3442.05 E2 2.72(-3)
Table 3: continued

 

Multiplet J-J' tex2html_wrap_inline1591(Å)a Type Aki
a1D-c3F 2-2 3433.13 E2 4.80(-2)
2-3 3420.40 E2 2.57(-1)
2-4 3400.90 E2 5.41(-1)
a1D-a1F 2-3 3081.77 E2 3.93(+0)
a3P-a5P 2-3 22162.28 M1 1.04(-3)
2-2 20954.77 M1 1.53(-3)*
1-1 20260.69 M1 2.89(-3)
a3P-b3P 2-2 9244.88 E2 9.36(-3)
2-1 9082.80 M1,E2 3.90(-2)
2-0 8965.67 E2 7.37(-2)
1-2 9369.40 M1,E2 1.91(-2)*
1-1 9202.96 M1,E2 1.83(-2)
0-2 9538.20 E2 7.98(-3)
a3P-c3P 2-2 8599.20 M1,E2 1.74(-2)*
2-1 8291.74 M1,E2 2.21(-3)*
1-2 8706.82 E2 2.48(-2)
1-1 8391.77 M1 1.06(-3)*
0-2 8852.42 E2 7.86(-3)
a3P-b1G 2-4 8410.52 E2 1.17(-2)
a3P-a3H 2-4 6827.97 E2 2.53(-3)
a3P-a3D 2-3 7028.51 M1,E2 1.83(-2)
2-2 6731.56 M1,E2 2.06(-2)
2-1 6245.07 M1,E2 1.70(-1)
1-3 7100.25 E2 1.11(-2)
1-2 6797.34 M1,E2 5.86(-3)
1-1 6301.64 M1,E2 1.02(-2)*
0-2 6885.75 E2 1.57(-2)
a3P-a1P 2-1 6979.10 M1,E2 5.33(-2)
1-1 7049.83 M1,E2 3.37(-2)*
0-1 7144.98 M1 2.53(-3)*
a3P-b1D 2-2 5572.98 E2 2.06(-1)
1-2 5617.98 M1,E2 4.40(-3)*
0-2 5678.24 E2 4.50(-3)
a3P-a5D 2-4 3643.96 E2 7.50(-3)
2-3 3563.61 M1,E2 2.19(-3)
2-1 3477.49 M1,E2 1.64(-3)*
1-3 3581.96 E2 2.99(-3)
1-2 3528.34 M1,E2 3.30(-3)
0-1 3518.19 M1 1.87(-3)
a3P-c3F 2-2 3633.96 E2 1.14(-1)
2-3 3619.71 E2 5.26(-1)
2-4 3597.87 E2 1.70(+0)
1-2 3653.04 E2 9.04(-1)
1-3 3638.64 E2 1.25(+0)
0-2 3678.43 E2 8.20(-1)
a3P-a1F 2-3 3242.64 E2 8.79(-1)
1-3 3257.83 E2 8.10(-3)
a5P-a5P 2-1 325485.09 M1 1.18(-3)
a5P-b3P 3-2 15861.40 M1 4.84(-3)
2-2 16543.69 M1 2.00(-3)*
2-1 16031.75 M1 1.03(-3)
1-2 17429.60 M1 1.18(-3)
1-1 16862.30 M1 2.44(-2)
1-0 16463.02 M1 4.75(-2)
a5P-c3P 3-2 14051.25 M1 1.72(-1)
2-2 14584.08 M1 9.32(-2)
1-2 15268.20 M1 1.93(-2)
1-1 14325.09 M1 1.42(-1)
1-0 13289.29 M1 1.49(-1)
Table 3: continued

 

Multiplet J-J' tex2html_wrap_inline1591(Å)a Type Aki

a5P-a3D

3-3 10292.77 M1 4.34(-2)
2-3 10575.80 M1 1.21(-2)
2-2 9917.51 M1 4.02(-2)
1-2 10229.20 M1 1.07(-2)
1-1 9146.48 M1 4.70(-3)
a5P-a1P 2-1 10464.33 M1 1.49(-3)
1-1 10811.93 M1 2.46(-2)
a5P-b1D 3-2 7445.18 M1 2.48(-3)
a5P-a5D 3-4 4361.04 E2 5.13(-1)
3-3 4246.44 E2 6.36(-1)
3-2 4171.30 E2 4.60(-1)
3-1 4124.73 E2 1.88(-1)
2-4 4411.05 E2 3.92(-1)
2-2 4217.04 E2 2.72(-1)
2-1 4169.44 E2 7.97(-1)
1-3 4351.26 E2 3.70(-1)
1-2 4272.39 E2 3.56(-1)
1-1 4223.55 E2 1.62(-1)
a5P-c3F 3-3 4326.34 M1,E2 1.22(-3)
3-4 4295.18 M1,E2 3.50(-3)
2-3 4375.56 E2 1.93(-3)
1-2 4456.60 M1,E2 1.65(-3)
1-3 4435.19 E2 3.27(-3)
a1G-b1G 4-4 16781.66 M1,E2 2.76(-3)
a1G-a3H 4-5 12075.42 M1,E2 3.58(-3)
4-4 11474.94 M1,E2 5.19(-3)*
a1G-a1H 4-5 8787.06 E2 1.19(-1)
a1G-b1D 4-2 8324.52 E2 1.61(-2)
a1G-c3F 4-3 4609.27 M1,E2 8.06(-3)
4-4 4573.92 M1,E2 4.28(-3)*
a1G-a1F 4-3 4014.80 E2 3.99(+0)
a3G-a3G 5-4 259784.18 M1 1.27(-3)
4-3 246767.08 M1 1.70(-3)
a3G-b1G 5-4 28379.33 M1 1.44(-2)
4-4 31859.76 M1 1.86(-3)*
3-4 36582.93 M1 1.05(-2)
a3G-a3H 5-6 18238.80 M1 4.18(-2)
5-5 17105.46 M1 4.14(-2)*
5-4 15924.97 M1 5.34(-3)
4-5 18311.16 M1,E2 1.97(-3)
4-4 16964.94 M1 7.16(-2)
3-4 18217.36 M1 3.19(-2)
a3G-a1H 5-5 11179.22 M1 1.10(-1)*
4-5 11681.93 M1 4.66(-2)
a3G-a5D 5-4 5242.12 M1,E2 1.19(-3)
a3G-c3F 5-3 5192.06 E2 1.79(-2)
5-4 5147.26 M1,E2 1.19(-1)
4-2 5328.54 E2 1.97(-2)
4-3 5297.95 M1,E2 2.79(-2)
4-4 5251.30 M1,E2 4.86(-2)*
3-2 5446.14 M1,E2 1.01(-1)
3-3 5414.19 M1,E2 7.07(-2)
3-4 5365.49 M1,E2 3.69(-3)
a3G-a1F 5-3 4449.86 E2 1.90(-3)
4-3 4527.41 M1,E2 1.09(-1)
3-3 4612.03 M1 6.89(-2)
b3P-c3P 2-1 80425.36 M1 2.86(-2)
1-2 161506.86 M1 3.02(-3)
1-0 62716.98 M1 8.84(-3)
Table 3: continued

 

Multiplet J-J' tex2html_wrap_inline1591(Å)a Type Aki
b3P-a3D 2-3 29317.43 M1 8.63(-3)
2-2 24761.29 M1 1.39(-2)
2-1 19246.36 M1 2.05(-2)
1-2 26004.16 M1 1.63(-3)
1-1 19988.94 M1 1.23(-2)*
0-1 20580.64 M1 2.35(-2)
b3P-a1P 2-1 28476.50 M1 2.39(-2)
1-1 30132.78 M1 3.08(-2)
0-1 31497.89 M1 3.22(-2)
b3P-b1D 1-2 14422.01 M1 1.79(-2)
b3P-c3F 2-2 5987.62 M1,E2 2.02(-3)
2-3 5949.02 M1,E2 3.26(-3)
2-4 5890.27 E2 3.81(-3)
1-2 6057.63 E2 1.62(-3)
0-2 6110.87 E2 2.28(-3)
b3P-a1F 1-3 5043.14 E2 2.30(-3)
c3P-c3P 1-0 183790.32 M1 5.46(-3)
c3P-a3D 2-3 38480.06 M1 1.24(-2)
2-2 30994.59 M1 1.88(-2)
2-1 22812.32 M1 5.63(-2)
1-2 35775.97 M1 1.17(-3)
1-1 25301.09 M1 5.33(-2)
0-1 29340.14 M1 1.18(-2)
c3P-a1P 2-1 37044.23 M1 1.35(-3)
1-1 44086.30 M1 1.75(-2)
0-1 57998.59 M1 2.32(-3)
c3P-b1D 2-2 15836.13 M1 1.36(-1)
1-2 16996.75 M1 1.02(-2)
c3P-c3F 2-2 6293.69 M1,E2 4.64(-3)*
2-3 6251.06 M1,E2 1.46(-2)
2-4 6186.22 E2 1.67(-2)
1-2 6469.25 M1,E2 1.67(-2)
1-3 6424.22 E2 8.60(-3)
0-2 6705.28 E2 6.96(-3)
b1G-a3H 4-5 43059.03 M1 1.65(-2)
4-4 36287.74 M1 1.78(-2)
b1G-a1H 4-5 18445.18 M1,E2 3.59(-3)
b1G-c3F 4-2 6398.75 E2 2.56(-3)
4-3 6354.69 M1,E2 4.29(-2)
4-4 6287.69 M1 6.49(-2)
b1G-a1F 4-3 5277.37 M1,E2 1.27(-3)*
a3H-a3H 5-4 230756.04 M1 1.88(-3)
a3H-a1H 6-5 28882.17 M1 1.11(-2)
4-5 37513.36 M1 5.74(-3)
a3H-c3F 6-4 7171.06 E2 3.57(-2)
5-3 7454.90 E2 2.70(-2)
5-4 7362.86 M1,E2 3.72(-3)
4-2 7768.63 E2 2.42(-2)
4-3 7703.78 M1,E2 4.20(-3)
a3H-a1F 5-3 6014.53 E2 2.21(-3)
a3D-a3D 3-2 159331.81 M1 4.42(-3)
2-1 86413.59 M1 2.74(-2)
a3D-b1D 3-2 26911.21 M1 2.50(-2)
2-2 32380.25 M1 6.74(-3)
1-2 51784.59 M1 1.68(-3)
Table 3: continued

 

Multiplet J-J' tex2html_wrap_inline1591(Å)a Type Aki
a3D-c3F 3-2 7524.36 M1,E2 1.52(-3)
3-3 7463.51 M1,E2 1.06(-2)*
3-4 7371.27 M1,E2 2.01(-2)
2-2 7897.31 M1,E2 1.20(-2)
2-3 7830.31 M1,E2 4.24(-3)
2-4 7728.84 E2 4.76(-3)
1-2 8691.65 M1,E2 2.90(-3)
a3D-a1F 3-3 6020.13 M1,E2 8.23(-3)*
2-3 6256.53 M1,E2 6.09(-3)
1-3 6744.88 E2 5.19(-3)
a1P-a3D 1-2 189791.64 M1 1.09(-3)
1-1 59378.22 M1 1.24(-2)
a1P-b1D 1-2 27661.02 M1 1.79(-2)
a1P-c3F 1-2 7581.83 M1,E2 4.62(-3)
1-3 7520.05 E2 3.90(-3)
a1P-a1F 1-3 6056.86 E2 5.39(-3)
a1H-a1F 5-3 7392.46 E2 3.19(-2)
b1D-c3F 2-2 10444.72 M1 2.46(-3)
2-3 10327.83 M1,E2 5.09(-3)
a5D-a5D 4-3 161611.29 M1 7.67(-3)
3-2 235729.18 M1 4.80(-3)
2-1 369448.43 M1 1.85(-3)
c3F-a1F 2-3 30113.81 M1 2.51(-3)
4-3 32843.85 M1 1.90(-3)
Table 3: continued

a Wavelengths, in air, are deduced from the observed energy levels compiled by Sugar & Corliss (1985).
* Cancellation effects present (see text).

The calculation of line strengths and transition probabilities involves the evaluation of the sum of several terms resulting of intermediate coupling and/or configuration interaction mixing of basis states. When strong basis function mixing is present, there frequently are destructive interference effects that cause a weak line to become still weaker or a strong line to nearly disappear. Consequently, in making numerical calculations on individual transitions, it is worthwhile evaluating the cancellation factors, CF, as defined by Cowan (1981). Small values of CF factors (typically CF tex2html_wrap_inline4015 0.01) indicate that the corresponding lines may be expected to show large percent errors. Such transitions are indicated by starred A-values in Table 3 (click here).

Although it is well established that the neglect of some configurations is partly overcome by scaling down the Slater integrals and by fitting the calculated energy levels to the observed values, the effects of configurations not included explicitly in our physical model due to computer memory limitations were estimated in separate semi-empirical HFR calculations. In particular, the 3s3p63d9, 3s3p63d84s and 3s3p63d74s2 configurations were investigated. As mentioned recently by Quinet & Hansen (1995), these configurations, corresponding to the core excitation 3s tex2html_wrap_inline1109 3d in 3s23p63d8, 3s23p63d74s and 3s23p63d64s2, might contribute to the transition probabilities for the forbidden lines considered in the present work. By comparing a three-configuration calculation (including 3d8, 3d74s and 3d64s2) with a six-configuration calculation (adding 3s3p63d9, 3s3p63d84s and 3s3p63d74s2), the effect on the A-values of the latter three configurations was estimated. In general, for the strongest multiplets (Atex2html_wrap_inline4081 tex2html_wrap_inline4083 0.01 s-1), both calculations agree within a few percent if we except a3F-b1G, a3F-a1P, a3F-b1D, b3F-a1P, a3P-c3P, a5P-b3P, a5P-a3D, a3G-a3G, b3P-a1P, b3P-b1D, a3D-a1F and a1P-b1D for which the multiplet A-values were tex2html_wrap_inline4161 larger when calculated with the six-configuration expansion. Exceptions occur also for the a3F-a5D, a1G-b1D and c3P-c3F lines for which the transition probabilities were reduced by about 25% when adding the 3s3p63d9, 3s3p63d84s and 3s3p63d74s2 configurations.

 

Multiplet J-J' tex2html_wrap_inline1591(tex2html_wrap_inline4213m) Type Aki(NS) Aki(HFR)
a3F-a3F 4-3 10.52 M1 2.23(-2) 2.21(-2)
3-2 15.46 M1 9.73(-3) 9.88(-3)
a3F-a5F 4-5 2.984 M1 4.90(-6) 3.09(-6)
a5F-a5F 5-4 14.74 M1 1.23(-2) 1.03(-2)
4-3 18.80 M1 1.08(-2) 9.27(-3)
3-2 25.67 M1 5.72(-3) 5.00(-3)
2-1 39.26 M1 1.78(-3) 1.57(-3)
a3F-b3F 4-4 1.019 E2 3.85(-2) 5.36(-2)
3-4 1.128 E2 4.91(-3) 6.33(-3)
2-4 1.217 E2 1.54(-4) 2.11(-4)
4-3 0.934 E2 1.63(-2) 2.30(-2)
3-3 1.025 E2 2.58(-2) 3.47(-2)
2-3 1.097 E2 6.97(-3) 8.74(-3)
4-2 0.883 E2 1.38(-3) 1.01(-3)
3-2 0.964 E2 1.87(-2) 2.60(-2)
2-2 1.028 E2 3.09(-2) 3.84(-2)
a5F-b3F 5-4 1.547 M1 2.89(-2) 2.66(-2)
4-4 1.728 M1 2.82(-3) 2.98(-3)
3-4 1.903 M1 4.28(-3) 4.81(-3)
4-3 1.497 M1 6.41(-3) 4.17(-3)
3-3 1.626 M1 4.91(-3) 4.53(-3)
2-3 1.736 M1 1.04(-2) 9.59(-3)
3-2 1.479 M1 5.38(-4) 1.99(-4)*
2-2 1.569 M1 5.30(-3) 4.34(-3)
1-2 1.634 M1 1.69(-2) 1.34(-2)
b3F-b3F 4-3 11.16 M1 1.87(-2) 1.67(-2)
3-2 16.30 M1 8.32(-3) 7.26(-3)
Table 4: Comparison of the transition probabilities, Aki in s-1, calculated in the present work (HFR) with those obtained by Nussbaumer & Storey (1988b) (NS) for the forbidden lines connecting the lowest three terms in Co II. A(B) stands for A.10B

* Cancellation effects present (see text).  

A very limited number of transition probabilities has been reported previously for [Co II] lines. To our knowledge, only the results obtained by Nussbaumer & Storey (1988b) for the forbidden transitions involving the first three terms, a3F, a5F and b3F, have been published. Their calculations were based on the multiconfiguration expansion of eigenfunctions as implemented in the SUPERSTRUCTURE code of Eissner et al. (1974) and modified by Nussbaumer & Storey (1978). In their study, the individual configurations were constructed from one-electron wavefunctions, the radial parts of which being calculated either in a scaled Thomas-Fermi-Dirac or a scaled Coulomb potential. The scaling parameters in the potentials were chosen to minimize the sum of the energies of the lowest three terms. Table 4 (click here) shows the comparison between the computations of Nussbaumer & Storey (1988b) and the present work. The agreement between the two sets of results is very good (within 15%) for the a3F-a3F, a5F-a5F, a5F-b3F and b3F-b3F magnetic dipole transitions if we except a5F4-b3F3 and a5F3-b3F2 for which larger discrepancies are observed. The difference can even reach a factor of three for the latter transition but, in that particular case, the A-value computed in our work is affected by strong cancellation effects and, consequently, could be uncertain. Larger differences (tex2html_wrap_inline4473) appear also when comparing our results with those obtained by Nussbaumer & Storey (1988b) for the a3F-a5F magnetic dipole and a3F-b3F electric quadrupole transitions. For these multiplets, the transitions arise through spin-orbit and configuration interactions and are therefore particularly sensitive to the choice of eigenfunctions. The magnitudes of the coefficients due to spin-orbit and CI depend on the a3F-a5F and a3F-b3F term separations. These term separations calculated in our work (3460 and 9757 cm-1) are in excellent agreement with the observations (3457 and 9774 cm-1) while the values obtained in intermediate coupling by Nussbaumer & Storey (1988b), i.e. 595 and 7551 cm-1, are too small.


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