SPEAKER: A. Humphrey (Porto)
ABSTRACT: In this talk I will discuss the flux ratio between the 1335 A and 2326 A lines of singly ionized carbon in the extended narrow line regions of type 2 quasars at z~2.5. This flux ratio, which is not sensitive to the C/H abundance ratio, is often several times higher than predicted by the canonical AGN photoionization models that use solar metallicity and a Maxwell-Boltzmann electron energy distribution. We study several potential solutions for this discrepancy: low gas metallicity, shock ionization, continuum fluorescence, and kappa-distributed electron energies. We argue that a kappa distribution gives the more natural explanation. The general impact on the UV-optical emission line spectrum of quasar ionized nebulae will also be discussed, using our newly computed grid of AGN photoionization models using kappa-distributed electron energies.