By NelmaS on Sáb, 14/04/2018 - 15:43
Instituto de Astronomía of the Universidad Nacional Autónoma de México
Various papers of Meléndez et al. (2008a,b, 2011 and 2014) have discussed new data on Mid-Infrared emission lines form Seyferts. My colaborator Mariela Paredes is one of their their collaborator of the 2014 paper. They discuss presented lines of [NeV], [OIV], [NeII] and [NeIII]. The surprizing aspect is that Meléndez et al. try to apply the results of Baskin & Laor 2005 who claimed that the density of the NLR in the region where [OIII] is emitted is of order log n_e ~ 5.85 cm-3. I analysed their result to icheck whether the NLR plasma is undergoing the same temperature problem as HII regions. I have used phootoionization code MAPPINGS Ie to derive calculations with t2 or with kappa. Meléndez et al showed that the density from NeV is on average 1000 cm-3. He argues in favor of small density values for [SIII], [NII] and [NeIII] regions but insist in enormously high density values for [OIII] (and [NeII]) !!!! The kappa models have recently met serious problems because of the time scale to reach temperature equipartion for the electrons, which is very short. A possibility might be that only the ions that develope a kappa distribution through a process that, at this stage, we can only speculate about.
17 de abril de 2018 | 13:30
Centro de Astrofísica da Universidade do Porto (Auditorium)
Rua das Estrelas, 4150-762 Porto