Author Archives: Paul Barklem

Excitation and charge transfer in low-energy hydrogen atom collisions with neutral oxygen

Barklem, P. S. Excitation and charge transfer in low-energy O+H collisions is studied; it is a problem of importance for modelling stellar spectra and obtaining accurate oxygen abundances in late-type stars including the Sun. The collisions have been studied theoretically … Continue reading

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Charge exchange in galaxy clusters

Gu, Liyi; Mao, Junjie; de Plaa, Jelle; Raassen, A. J. J.; Shah, Chintan; Kaastra, Jelle S. Context. Though theoretically expected, the charge exchange emission from galaxy clusters has never been confidently detected. Accumulating hints were reported recently, including a rather … Continue reading

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Line Ratios for Solar Wind Charge Exchange with Comets

Mullen, P. D.; Cumbee, R. S.; Lyons, D.; Gu, L.; Kaastra, J.; Shelton, R. L.; Stancil, P. C. Charge exchange (CX) has emerged in X-ray emission modeling as a significant process that must be considered in many astrophysical environments—particularly comets. … Continue reading

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The impact of atomic data selection on nebular abundance determinations

Juan de Dios, Leticia; Rodríguez, Mónica Atomic data are an important source of systematic uncertainty in our determinations of nebular chemical abundances. However, we do not have good estimates of these uncertainties since it is very difficult to assess the … Continue reading

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PhD position in atomic astrophysics

Malmö University and Lund Observatory jointly announce a PhD position in Atomic Astrophysics. The candidate will work within the project ‘Experimental and Computational Atomic Astrophysics’ For information and online application, please see the link below. http://web103.reachmee.com/ext/I005/1015/job?site=6&lang=SE&validator=df9f5539db53eab37b3e3087d2a2669b&job_id=238 The deadline for application … Continue reading

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Testing atomic collision theory with the two-photon continuum of astrophysical nebulae

Guzmán, F.; Badnell, N. R.; Chatzikos, M.; van Hoof, P. A. M.; Williams, R. J. R.; Ferland, G. J. Accurate rates for energy-degenerate l-changing collisions are needed to determine cosmological abundances and recombination. There are now several competing theories for … Continue reading

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K-shell photoionization of O4 + and O5 + ions: experiment and theory

McLaughlin, B. M.; Bizau, J.-M.; Cubaynes, D.; Guilbaud, S.; Douix, S.; Shorman, M. M. Al; Ghazaly, M. O. A. El; Sakho, I.; Gharaibeh, M. F. Absolute cross-sections for the K-shell photoionization of Be-like (O4 +) and Li-like (O5 +) atomic … Continue reading

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