Next Generation Accretion Disk Reflection Model: High-Density Plasma Effects

Luminous accretion disks are expected to have a density high enough such that plasma physics effects become important. Many of these effects have been traditionally neglected in the calculation of atomic parameters, and therefore from photoionization models, and thus also from X-ray reflection models. In this presentation, we describe updates to the atomic rates used by the XSTAR code, which is in turn part of the XILLVER disk reflection model. We discuss the effect of adding necessary high density corrections into the XILLVER code. Specifically, we find that the change of recombination rates play an important role, dominating the differences between model versions. With synthetic spectra, we show that even in a highly ionized state, high density slabs can produce strong iron K (~6 keV), oxygen, nitrogen and silicon (~0.8-1.2 keV) features. The significantly stronger iron K emission could address the problem of the supersolar iron abundances found in some sources.