High Precision {\it K}-Shell Photoabsorption Cross Sections for Atomic Oxygen: Experiment and Theory
| Autor: | McLaughlin, B. M., Ballance, C. P., Bowen, K. P., Gardenghi, D. J., Stolte, W. C. |
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| Rok vydání: | 2013 |
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| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/2041-8205/771/1/L8 |
| Popis: | Photoabsorption of atomic oxygen in the energy region below the $\rm 1s^{-1}$ threshold in x-ray spectroscopy from {\it Chandra} and {\it XMM-Newton} is observed in a variety of x-ray binary spectra. Photoabsorption cross sections determined from an R-matrix method with pseudo-states (RMPS) and new, high precision measurements from the Advanced Light Source (ALS) are presented. High-resolution spectroscopy with E/$\Delta$E $\approx$ 4,250 $\pm$ 400 was obtained for photon energies from 520 eV to 555 eV at an energy resolution of 124 $\pm$ 12 meV FWHM. {\it K}-shell photoabsorption cross-section measurements were made with a re-analysis of previous experimental data on atomic oxygen at the ALS. Natural linewidths $\Gamma$ are extracted for the $\rm 1s^{-1}2s^22p^4 (^4P)np ^3P^{\circ}$ and $\rm 1s^{-1}2s^22p^4(^2P)np ~^3P^{\circ}$ Rydberg resonances series and compared with theoretical predictions. Accurate cross sections and linewidths are obtained for applications in x-ray astronomy. Excellent agreement between theory and the ALS measurements is shown which will have profound implications for the modelling of x-ray spectra and spectral diagnostics. Comment: Accepted for publication in Ap J Letters; 4 figures and a table |
| Databáze: | arXiv |
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