Variations in the 6.2 μm emission profile in starburst-dominated galaxies : a signature of polycyclic aromatic nitrogen heterocycles (PANHs)?
| Autor: | Canelo, Carla Martinez, Friaça, Amâncio César Santos, Sales, Dinalva Aires de, Pastoriza, Miriani Griselda, Dutra, Daniel Ruschel |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Repositório Institucional da UFRGS Universidade Federal do Rio Grande do Sul (UFRGS) instacron:UFRGS |
| Popis: | Analyses of the polycyclic aromatic hydrocarbon (PAH) feature profiles, especially the 6.2 μm feature, could indicate the presence of nitrogen incorporated in their aromatic rings. In thiswork, 155 predominantly starburst-dominated galaxies (includingHII regions and Seyferts, for example), extracted from the Spitzer/Infrared Spectrograph ATLAS project, have their 6.2 μmprofiles fitted allowing their separation into the Peeters’ A, B, and C classes. 67 per cent of these galaxies were classified as class A, 31 per cent were as class B, and 2 per cent as class C. Currently, class A sources, corresponding to a central wavelength near 6.22 μm, seem only to be explained by polycyclic aromatic nitrogen heterocycles (PANHs), whereas class B may represent a mix between PAHs and PANHs emissions or different PANH structures or ionization states. Therefore, these spectra suggest a significant presence of PANHs in the interstellar medium (ISM) of these galaxies that could be related to their starburst-dominated emission. These results also suggest that PANHs constitute another reservoir of nitrogen in the Universe, in addition to the nitrogen in the gas phase and ices of the ISM. |
| Databáze: | OpenAIRE |
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