2007MNRAS.375..685P

The problem of determination of the electron temperature t₂ in the O⁺ zone of high-metallicity Hii regions is examined. It is shown that the ratio of nebular to auroral nitrogen line intensities, which is an indicator of the electron temperature t₂, can be expressed in terms of the nebular line intensities of oxygen. This solves the problem of the determination of the electron temperature t₂, since the oxygen nebular lines are strong and, consequently, are readily observable. A relation between electron temperatures in the O⁺ and O⁺⁺ zones in high-metallicity Hii regions is studied. It is found that there is no one-to-one correspondence between t₂and t₃temperatures. Instead the t₂-t₃relation is dependent on the excitation parameter.