IA/U.Porto Seminar - Evidence of a temperature problem similar in the NLR as in HII regions - 17 abril 2018



Evidence of a temperature problem similar in the NLR as in HII regions

Luc Binette

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




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