1. M. Fatih Hasoglu Thomas W. Gorczyca
X-ray absorption by interstellar atomic gases near the K-edges of C, O, Ne, Mg, and Si, and the L-edge of Fe
M. Fatih Hasoglu Thomas W. Gorczyca
AtomDB UGA 11/4/17

2. Outline Previous X-ray Photoabsorption Calculations Current Work
Simplest Neutral Neon and Ions
Carbon Isonuclear Sequence
Oxygen Isonuclear Sequence
Mg Isonuclear Sequence
Current Work
Si K-shell
Fe L-shell
Perturbed Hydrogen Photoabsorption (Multiple Scattering)

3. Theoretical Methodology
Belfast R-matrix Codes: Cross Sections and Auger Rates
Pseudoresonance Elimination
Inclusion of Radiative and Spectator Auger Broadening
Wigner Time-Delay Method for Spectator Auger Rates
Autostructure: DW Wavefunctions, Auger and Radiative Rates
An extension of SUPERSTRUCTURE. Eissner et al. CPC 8, 220 (1972).
Charlotte F. Fischer’s MCHF: Improved Atomic Structure and Energies. Charlotte Froese Fischer et al. CPC 176, 559 (2007).

4. Photobsorption: Atomic Physics Perspective
I0=Source Intensity
I =Observed Intensity
σ = Absorption Cross Section
N = Column Density
n = Number / Volume
Cross Section = Golden Rule Rate / (Poynting Vector/Photon Energy)

5. 6/2/2016

6. Simplest K-Shell Photoabsorption: Neon
Experiment : Coreno et al. (1999)
Theory: Gorczyca (2000)
Optical Potential R-matrix with Auger Broadening
Participator Auger Decays
Spectator Auger Decays
Standard R-matrix vs R-matrix with Auger Broadening
Experiment vs. Theory
Excellent agreement with Experiment!

7. Ne : QDT Parameterization of Rydberg Series
9/21/2018

8. Ne Isonuclear Sequence and High Resolutions X-Ray…
Photoabsorption Cross Sections
X-Ray Spectra Ne Abundance in the ISM
Intensity:
I = I0 e-σN
Column Density:
N = ∫ n dx

9. X-Ray Spectra O Abundance in the ISM
Best broadband fits with the TBnew model of the spectra toward eight Galactic low-mass X-ray binaries. For each source the observation with highestsignal-to-noise ratio is shown.
E. Gatuzz et al. ApJ 790, 131 (2014)
X-Ray Spectra O Abundance in the ISM

10. Carbon Cross Sections: ISM Modelling
First detection of interstellar C II.

11. Mg I – X Isonuclear Sequence Cross Sections
Mg VIII
Mg II
Hasoglu et al., ApJS 214, 8 (2014).
Witthoeft et al. , ApJS, 182, 127 (2009).
No Mg I, Mg II K-edge over estimated.
Verner et al. (1993)
_____
____

12. Fe L-Edge and Si K-Edge Spectra
Ne and O K-Edge Spectra
vs.
Fe L-Edge and Si K-Edge Spectra
Atomic
Si K Region: Solid-State
Solid-State
Molecular or Solid-State Oxygen Abundance?
Atomic Silicon or Iron Abundance?
Atomic

13. Chandra X-ray Observation for the Si K-edge
Observed Si K edge region from Galactic Bulge source GX 3+1, with NH= 3.5 x cm -2 Preliminary measurements of this source indicate a two-part edge, with solid silicate at keV plus a contribution presumably from atomic Si at keV from Norbert S. Schulz et al. ApJ 827:49 (2016).

14. Available Si K-edge Photoabsoprtion Cross Sections
L. R. Corrales et al., MNRAS 458, 1345 (2016) : Si Dust cross section Astrophysics Modelling of Chandra Observations.
S. T. Zeegers et al., A&A 599, A117 (2017) : Si (olivine) cross section per Si atom - Astrophysics Modelling of Chandra Observations and Experiment.

15. Theoretical R-Matrix Cross Sections for Si Atom

16. Atomic Si vs. Silicate Dust – Silicon Mineral

17. Fe L-Edge – Experiment for Solid State Fe
Poor Man's shift, semi relativistic BP calculations are required and we are working on it.
Solid Iron.
Experiment near L-Edge for Solid Fe: Kortright, J. B. & Kim, S.-K. 2000, Phys. Rev. B, 62,

18. Fe L-Edge – Minimal R-Matrix in LS vs Exp.
Poor Man's shift, semi relativistic BP calculations are required and we are working on it.
Solid Iron.

19. Fe L-Edge – Minimal R-Matrix in LS vs Exp.
Poor Man's shift, semi relativistic BP calculations are required and we are working on it.
Solid Iron.
Experiment near L-Edge for Solid Fe: Kortright, J. B. & Kim, S.-K. 2000, Phys. Rev. B, 62,

20. Multiphase Oxygen Photoabsorption Cross Sections
O and O2 Gas
H2O Gas
9/21/2018

21. Photoionization in Atoms:
Photoionization in Solids:
(XAFS)

22. H + Perturber: Modified K-Matrix Modified Amplitude

23. Analytic Behavior, H + Delta Function Perturber
The cross section above threshold is modified by a factor that oscillates about unity, with an oscillation magnitude that depends on the ratio V0 /R2 and also the Coulomb amplitudes sl(R) and cl(R).
The cross section below threshold is now split into two Rydberg series, one at the unperturbed positions ν = n and a second series at ν = n-μ0 ; for weak perturbations V 0 /R2 << 1, most of the oscillator strength remains in the original positions ν = n series, and the remainder is transferred into the second, quantum-defect-shifted series.
More general case requires analytic transformation of K-matrices, from each scattering site, via Green’s function techniques – future work!

24. Acknowledgments Astrophysics Atomic Physics Funded by NASA APRA
K. T. Korista, Western Michigan University
T. R. Kallman, NASA Goddard Space Flight Center
C. Mendoza, Western Michigan University
M. A. Bautista, Western Michigan University
J. Garcia, Cahill Center for Astronomy and Astrophysics (Caltech)
E. Gatuzz, Centro de Fisica, Instituto Venezolano de Investigaciones Cientificas
J. J. Drake, Harvard-Smithsonian Center for Astrophysics
Norbert Schulz, MIT/Kavli
Atomic Physics
S. T. Manson, Georgia State University
B. M. McLaughlin, Queen’s University Belfast
Funded by NASA APRA
Consulting with Manson and Brendan

25. WMU Graduate Students in Theoretical Atomic Physics