Photoionization Of Ne III For Astrophysical Applications

Photoionization is one process that introduces lines for neon ions seen in astrophysical plasmas such as of quasers, planetary nebulae, supernova ramnents. The present study on photoionization of Ne III, Ne III + h$\nu~ \rightarrow$ e + Ne IV, reports features and characteristics in cross sections ($\sigma$) obtained from the relativistic Breit-Pauli R-Matrix method using a close coupling wavefunction expansion of 58 levels of the residual ion Ne IV of configuratioins $2s^22p^3$, $2s2p^4$, $2p^5$, $2s^22p^23s$, $2s^22p^23p$, $2s^22p^23d$, $2s2p^33s$. Along with narrow Rydberg resonances, wide Seaton resonances due to photoexcitation-of-core (PEC) are noted in $\sigma$. Although relatively a low Z ion, it shows distinct relativic effects in the low energy region near the ionization threshold by producing resonances through couplings of fine structure channels. Such resonances, not allowed in LS coupling, can explain the the observed features in the measured $\sigma$ carried out at the sophisticated facility of Advanced Light Source in Berkeley. These features will be demonstrated at the presentation.