The interpretation of cosmic spectra relies on a vast sea of atomic data which are not readily obtainable from analytic expressions or simple calculations. Rather, their evaluation typically requires state-of-the-art atomic physics calculations, with the inclusion of weaker effects (spin-orbit and configuration interactions, relaxation, Auger broadening, etc.), to achieve the level of accuracy needed for use by astrophysicists. Our NASA-supported research program is focused on calculating data for three important atomic processes, 1) dielectronic recombination (DR), 2) inner-shell photoabsorption, and 3) fluorescence and Auger decay of inner-shell vacancy states. Some additional details and examples of our recent findings are given below

Badnell, N. R.

Dumitriu, I.

Fu, J.

Gorczyca, T. W.

Hasoǧlu, M. F.

Korista, K. T.

Manson, S. T.

Nikolic, D.

Savin, Daniel Wolf

Columbia University Academic Commons

NASA LAW, February 14-16, 2006, UNLV, Las VegasCalculation of Atomic Data for NASA MissionsT. W. Gorczyca,1 K. T. Korista,1 J. Fu,1∗ D. Nikolic´,1∗ M. F. Hasoglu,1† I. Dumitriu,1†N. R. Badnell,2 D. W. Savin,3 and S. T. Manson41Department of Physics, Western Michigan University, Kalamazoo, MI 49008-52522Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK3Columbia Astrophysics Laboratory, Columbia University, New York, NY 100274Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303∗Postdoctoral Research Associates supported by NASA†Graduate Students supported by NASAABSTRACTThe interpretation of cosmic spectra relies on a vast sea of atomic datawhich are not readily obtainable from analytic expressions or simple calcula-tions. Rather, their evaluation typically requires state-of-the-art atomic physicscalculations, with the inclusion of weaker effects (spin-orbit and configurationinteractions, relaxation, Auger broadening, etc.), to achieve the level of accu-racy needed for use by astrophysicists. Our NASA-supported research programis focused on calculating data for three important atomic processes, 1) dielec-tronic recombination (DR), 2) inner-shell photoabsorption, and 3) fluorescenceand Auger decay of inner-shell vacancy states. Some additional details and ex-amples of our recent findings are given below.1. Dielectronic RecombinationWe have completed the computation of DR rate coefficients, including fitting formula,for all H-like through Na-like ions up to nuclear charge Z = 30. For the Fe ions, we are able tobenchmark R-matrix and AUTOSTRUCTURE results using storage ring experiments. Thesedata are available electronically at http://homepages.wmich.edu/∼gorczyca/atomicdataand http://amdpp.phys.strath.ac.uk/tamoc/DATA/. Our latest challenging work is for3rd and 4th row elements where partially filled n = 3 and n = 4 shells lead to more compli-cated calculations (relaxation, larger configuration-interaction, etc.)An example of our latest difficulties when addressing occupation of the n = 3 shell is DRof Ne-like Mg III. Figure 1 shows how the computed DR rate coefficients are extremely sensi-tive to the choice of atomic orbitals, and thus more sophisticated approaches for determining– 191 –00.050.10.150.20.2510 100 1000αDR (10-11 cm3  s-1 )Electron Temperature (eV)Mazzotta et al. (1998)Zatsarinny et al. (2004)λ-scaled non-orth. orbitalGu (2003)Ground state orbitalFig. 1.— Sensitivity of Maxwellian DR rate coefficients to the choice of target orbitals used.atomic structure is necessary. Our latest calculations utilizing λ-scaled non-orthogonal or-bitals resolve a factor of ≈ 2 difference between our earlier results (Zatsarinny et al. 2004)and the results of Gu (2003), and are less than half the recommended data of Mazzotta etal. (1998). 0 0.05 0.1 0.15 0.2 0  5  10  15  20  25  30ωKZFig. 2.— Calculated fluorescence yields ωCIK (solid circles) and fitted formula ωfitK = [1 +(aZ4 − bZ7)−1]−1 (solid line) for K-shell vacancy Li-like 1s2s2 ions.– 192 –2. K-Shell Fluorescence YieldsWe have also calculated new fluorescence yields for all second-row K-shell-vacancy iso-electronic sequences, where the inclusion of higher-order effects (fine structure, configurationinteraction, term dependence, etc.) frequently give results (Gorczyca et al. 2003) that dif-fer considerably from the currently recommended data of Kaastra & Mewe (1993). Forinstance, recent work on the Li-like sequence (Gorczyca et al. 2006) demonstrated theimportance of 1s2s2 + 1s2p2 CI: this state cannot radiate in a single-configuration modeldescription. Further, we were able to develop a two-parameter fitting formula for all Z:ωfitK = [1 + (aZ4− bZ7)−1]−1. These results are shown in Figure 2.(b)13.5 14.0 14.5 15.07.5147.0126.5106.085.55.0Flux (10photons scmÅ)-2-1-2-1Wavelength (Å)Ne IXNe INe IIINe IINe IXNe INe IIINe II840 860 880 900 920 940 960 980 100010-210-1100101102Ne VNe IVNe IIINe IINe I(a)Gorczyca (2000)Reilman & Manson (1979)Juett et al. (2006, in press)Fig. 3.— (a) Theoretical R-matrix photoabsorption cross sections for neutral neon (Gorczyca2000) and ionized neon (Juett et al. 2006) compared to independent particle results (Reilman& Manson 1979) which do not include resonances. (b) Using our atomic cross sections σ(λ),X-ray absorption spectra of the Cygnus black hole X-ray binary were fitted using intensitiesI = I0e−σ(λ)N to determine elemental abundances (column densities N) by Juett et al. (2006).– 193 –3. K-Shell PhotoabsorptionWe have recently calculated K-shell photoabsorption cross sections for all oxygen andneon ions (see Fig. 3a for neon ions). While results for the neutral O I and Ne I speciescompare favorably to experimental measurements (Gorczyca & McLaughlin 2000; Gorczyca2000), our results for ionized oxygen (Garcia et al. 2005) and neon (Juett et al. 2006) are theonly complete data available to our knowledge. These newly computed data have alreadybeen used to infer elemental abundances in the ISM by Juett et al. (2004, 2006) (see Fig. 3bfor neon ion abundances).This work was supported in part by the NASA APRA program.REFERENCESGarcia, J., Mendoza, C., Bautista, M. A., Gorczyca, T. W., Kallman, T. R., & Palmeri, P.2005, Astrophys. J. Suppl. Ser., 158, 68Gorczyca, T. W. 2000, Phys. Rev. A, 61, 024702Gorczyca, T. W., & McLaughlin, B. M. 2000, J. Phys. B, 33, L859Gorczyca, T. W., Kodituwakku, C. N., Korista, K. T., Zatsarinny, O., Badnell, N. R., Behar,E., Chen, M. H., & Savin, D. W. 2003, Astrophys. J., 592, 636Gorczyca, T. W., Dumitriu, I., Hasoglu, M. F., Korista, K. T., Badnell, N. R., Savin, D. W.,& Manson, S. T. 2006, Astrophys. J., 638, L121Gu, M. F. 2003, ApJ, 590, 1131Juett, A. M., Schulz, N. S., & Chakrabarty, D. 2004, Astrophys. J., 612, 308Juett, A. M., Schulz, N. S., Chakrabarty, D., & Gorczyca, T. W. 2006, Astrophys. J., inpressKaastra, J. S., & Mewe, R. 1993, Astron. Astrophys. Suppl. Ser., 97, 443Mazzotta, P., Mazzitelli, G., Colafrancesco, S. & Vittorio, N. 1998, Astron. Astro-phys. Suppl. Ser., 133, 403Reilman, R. F., & Manson, S. T. 1979, Astron. Astrophys. Suppl. Ser., 40, 815Zatsarinny, O., Gorczyca, T. W., Korista, K., Badnell, N. R., & Savin, D. W. 2004, As-tron. Astrophys., 426, 699

Calculation of Atomic Data for NASA Missions

The interpretation of cosmic spectra relies on a vast sea of atomic data which are not readily obtainable from analytic expressions or simple calculations. Rather, their evaluation typically requires state-of-the-art atomic physics calculations, with the inclusion of weaker effects (spin-orbit and configuration interactions, relaxation, Auger broadening, etc.), to achieve the level of accuracy needed for use by astrophysicists. Our NASA-supported research program is focused on calculating data for three important atomic processes, 1) dielectronic recombination (DR), 2) inner-shell photoabsorption, and 3) fluorescence and Auger decay of inner-shell vacancy states. Some additional details and examples of our recent findings are given

Hasoglu, M. F.

Savin, D. W.

NASA Technical Reports Server

NASA LAW, February 14-16, 2006, UNLV, Las Vegas
Calculation of Atomic Data for NASA Missions
T. W. Gorczyca,1 K. T. Korista,1 J. Fu,1∗ D. Nikolic´,1∗ M. F. Hasoglu,1† I. Dumitriu,1†
N. R. Badnell,2 D. W. Savin,3 and S. T. Manson4
1Department of Physics, Western Michigan University, Kalamazoo, MI 49008-5252
2Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
3Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027
4Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303
∗Postdoctoral Research Associates supported by NASA
†Graduate Students supported by NASA
ABSTRACT
The interpretation of cosmic spectra relies on a vast sea of atomic data
which are not readily obtainable from analytic expressions or simple calcula-
tions. Rather, their evaluation typically requires state-of-the-art atomic physics
calculations, with the inclusion of weaker effects (spin-orbit and configuration
interactions, relaxation, Auger broadening, etc.), to achieve the level of accu-
racy needed for use by astrophysicists. Our NASA-supported research program
is focused on calculating data for three important atomic processes, 1) dielec-
tronic recombination (DR), 2) inner-shell photoabsorption, and 3) fluorescence
and Auger decay of inner-shell vacancy states. Some additional details and ex-
amples of our recent findings are given below.
1. Dielectronic Recombination
We have completed the computation of DR rate coefficients, including fitting formula,
for all H-like through Na-like ions up to nuclear charge Z = 30. For the Fe ions, we are able to
benchmark R-matrix and AUTOSTRUCTURE results using storage ring experiments. These
data are available electronically at http://homepages.wmich.edu/∼gorczyca/atomicdata
and http://amdpp.phys.strath.ac.uk/tamoc/DATA/. Our latest challenging work is for
3rd and 4th row elements where partially filled n = 3 and n = 4 shells lead to more compli-
cated calculations (relaxation, larger configuration-interaction, etc.)
An example of our latest difficulties when addressing occupation of the n = 3 shell is DR
of Ne-like Mg III. Figure 1 shows how the computed DR rate coefficients are extremely sensi-
tive to the choice of atomic orbitals, and thus more sophisticated approaches for determining
https://ntrs.nasa.gov/search.jsp?R=20060052444 2019-08-29T18:47:03+00:00Z
– 191 –
0
0.05
0.1
0.15
0.2
0.25
10 100 1000
α
D
R
 
(10
-
11
 
cm
3  
s-
1 )
Electron Temperature (eV)
Mazzotta et al. (1998)
Zatsarinny et al. (2004)
λ-scaled non-orth. orbital
Gu (2003)
Ground state orbital
Fig. 1.— Sensitivity of Maxwellian DR rate coefficients to the choice of target orbitals used.
atomic structure is necessary. Our latest calculations utilizing λ-scaled non-orthogonal or-
bitals resolve a factor of ≈ 2 difference between our earlier results (Zatsarinny et al. 2004)
and the results of Gu (2003), and are less than half the recommended data of Mazzotta et
al. (1998).
 0
 0.05
 0.1
 0.15
 0.2
 0  5  10  15  20  25  30
ω
K
Z
Fig. 2.— Calculated fluorescence yields ωCIK (solid circles) and fitted formula ω
fit
K = [1 +
(aZ4 − bZ7)−1]−1 (solid line) for K-shell vacancy Li-like 1s2s2 ions.
– 192 –
2. K-Shell Fluorescence Yields
We have also calculated new fluorescence yields for all second-row K-shell-vacancy iso-
electronic sequences, where the inclusion of higher-order effects (fine structure, configuration
interaction, term dependence, etc.) frequently give results (Gorczyca et al. 2003) that dif-
fer considerably from the currently recommended data of Kaastra & Mewe (1993). For
instance, recent work on the Li-like sequence (Gorczyca et al. 2006) demonstrated the
importance of 1s2s2 + 1s2p2 CI: this state cannot radiate in a single-configuration model
description. Further, we were able to develop a two-parameter fitting formula for all Z:
ω
fit
K = [1 + (aZ
4
− bZ7)−1]−1. These results are shown in Figure 2.
(b)
13.5 14.0 14.5 15.0
7.5
14
7.0
12
6.5
10
6.0
8
5.5
5.0
F
lu
x
(1
0
ph
ot
on
s
s
cm
Å
)
-2
-1
-2
-1
Wavelength (Å)
Ne IX
Ne I
Ne III
Ne II
Ne IX
Ne I
Ne III
Ne II
840 860 880 900 920 940 960 980 1000
10
-2
10
-1
10
0
10
1
10
2
Ne V
Ne IV
Ne III
Ne II
Ne I
(a)
Gorczyca (2000)
Reilman & Manson (1979)
Juett et al. (2006, in press)
Fig. 3.— (a) Theoretical R-matrix photoabsorption cross sections for neutral neon (Gorczyca
2000) and ionized neon (Juett et al. 2006) compared to independent particle results (Reilman
& Manson 1979) which do not include resonances. (b) Using our atomic cross sections σ(λ),
X-ray absorption spectra of the Cygnus black hole X-ray binary were fitted using intensities
I = I0e
−σ(λ)N to determine elemental abundances (column densities N) by Juett et al. (2006).
– 193 –
3. K-Shell Photoabsorption
We have recently calculated K-shell photoabsorption cross sections for all oxygen and
neon ions (see Fig. 3a for neon ions). While results for the neutral O I and Ne I species
compare favorably to experimental measurements (Gorczyca & McLaughlin 2000; Gorczyca
2000), our results for ionized oxygen (Garcia et al. 2005) and neon (Juett et al. 2006) are the
only complete data available to our knowledge. These newly computed data have already
been used to infer elemental abundances in the ISM by Juett et al. (2004, 2006) (see Fig. 3b
for neon ion abundances).
This work was supported in part by the NASA APRA program.
REFERENCES
Garcia, J., Mendoza, C., Bautista, M. A., Gorczyca, T. W., Kallman, T. R., & Palmeri, P.
2005, Astrophys. J. Suppl. Ser., 158, 68
Gorczyca, T. W. 2000, Phys. Rev. A, 61, 024702
Gorczyca, T. W., & McLaughlin, B. M. 2000, J. Phys. B, 33, L859
Gorczyca, T. W., Kodituwakku, C. N., Korista, K. T., Zatsarinny, O., Badnell, N. R., Behar,
E., Chen, M. H., & Savin, D. W. 2003, Astrophys. J., 592, 636
Gorczyca, T. W., Dumitriu, I., Hasoglu, M. F., Korista, K. T., Badnell, N. R., Savin, D. W.,
& Manson, S. T. 2006, Astrophys. J., 638, L121
Gu, M. F. 2003, ApJ, 590, 1131
Juett, A. M., Schulz, N. S., & Chakrabarty, D. 2004, Astrophys. J., 612, 308
Juett, A. M., Schulz, N. S., Chakrabarty, D., & Gorczyca, T. W. 2006, Astrophys. J., in
press
Kaastra, J. S., & Mewe, R. 1993, Astron. Astrophys. Suppl. Ser., 97, 443
Mazzotta, P., Mazzitelli, G., Colafrancesco, S. & Vittorio, N. 1998, Astron. Astro-
phys. Suppl. Ser., 133, 403
Reilman, R. F., & Manson, S. T. 1979, Astron. Astrophys. Suppl. Ser., 40, 815
Zatsarinny, O., Gorczyca, T. W., Korista, K., Badnell, N. R., & Savin, D. W. 2004, As-
tron. Astrophys., 426, 699


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Calculation of Atomic Data for NASA Missions

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