Modelling the Multifrequency SED of AGN Candidates among the Unidentied EGRET and Fermi Gamma-Ray Sources
Of the 271 sources in the 3rd EGRET catalogue, 131 were reported as unidentied, i.e. not associated with any particular class of point source in the sky. Since the largest fraction of the EGRET sources were extragalactic, a sample of 13 extragalactic unidentied sources have been selected for multi-w...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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CTU Central Library
2014-12-01
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| Series: | Acta Polytechnica CTU Proceedings |
| Online Access: | https://ojs.cvut.cz/ojs/index.php/APP/article/view/2376 |
| _version_ | 1818427854621245440 |
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| author | Pieter J. Meintjes Pheneas Nkundabakura Brian van Soelen Alida Odendaal |
| author_facet | Pieter J. Meintjes Pheneas Nkundabakura Brian van Soelen Alida Odendaal |
| author_sort | Pieter J. Meintjes |
| collection | DOAJ |
| description | Of the 271 sources in the 3rd EGRET catalogue, 131 were reported as unidentied, i.e. not associated with any particular class of point source in the sky. Since the largest fraction of the EGRET sources were extragalactic, a sample of 13 extragalactic unidentied sources have been selected for multi-wavelength follow-up studies. Five of the selected EGRET sources coincide with gamma-ray flux enhancements seen in the Fermi-LAT data after one year of operation. In this article, we report the multi-wavelength properties of, among others, the 5 sources detected by Fermi-LAT from our sample of high galactic latitude unidentied EGRET sources. Recent spectroscopic observations with the Southern African Large Telescope (SALT) conrmed one of the unidentied EGRET sources as a possible Seyfert 2 galaxy, or alternatively, a narrow line radio galaxy. The detected gamma-ray emission (E<sub>γ</sub> > 30 MeV) of the 5 coinciding EGRET/Fermi-LAT sources are tted with external Compton and Synchrotron Self Compton (SSC) models to investigate the energetics required to produce the EGRET/Fermi gamma-ray flux. In all the models the inclination angle of the jet with respect to the observer is jet 60, between those of Seyfert 1 and Seyfert 2/radio galaxies. These results confirm the possibility of Seyfert and radio galaxies sources are constituting a new class of gamma-ray source in the energy range E<sub>γ</sub> > 30 MeV. |
| first_indexed | 2024-12-14T14:52:21Z |
| format | Article |
| id | doaj.art-7c165cda54f14b9cb30512c61b96ab04 |
| institution | Directory Open Access Journal |
| issn | 2336-5382 |
| language | English |
| last_indexed | 2024-12-14T14:52:21Z |
| publishDate | 2014-12-01 |
| publisher | CTU Central Library |
| record_format | Article |
| series | Acta Polytechnica CTU Proceedings |
| spelling | doaj.art-7c165cda54f14b9cb30512c61b96ab042022-12-21T22:57:05ZengCTU Central LibraryActa Polytechnica CTU Proceedings2336-53822014-12-011116316910.14311/APP.2014.01.01632186Modelling the Multifrequency SED of AGN Candidates among the Unidentied EGRET and Fermi Gamma-Ray SourcesPieter J. Meintjes0Pheneas Nkundabakura1Brian van Soelen2Alida Odendaal3Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South-AfricaKigali Institute of Education, P.O. Box 5039, Kigali, RwandaDepartment of Physics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South-AfricaDepartment of Physics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South-AfricaOf the 271 sources in the 3rd EGRET catalogue, 131 were reported as unidentied, i.e. not associated with any particular class of point source in the sky. Since the largest fraction of the EGRET sources were extragalactic, a sample of 13 extragalactic unidentied sources have been selected for multi-wavelength follow-up studies. Five of the selected EGRET sources coincide with gamma-ray flux enhancements seen in the Fermi-LAT data after one year of operation. In this article, we report the multi-wavelength properties of, among others, the 5 sources detected by Fermi-LAT from our sample of high galactic latitude unidentied EGRET sources. Recent spectroscopic observations with the Southern African Large Telescope (SALT) conrmed one of the unidentied EGRET sources as a possible Seyfert 2 galaxy, or alternatively, a narrow line radio galaxy. The detected gamma-ray emission (E<sub>γ</sub> > 30 MeV) of the 5 coinciding EGRET/Fermi-LAT sources are tted with external Compton and Synchrotron Self Compton (SSC) models to investigate the energetics required to produce the EGRET/Fermi gamma-ray flux. In all the models the inclination angle of the jet with respect to the observer is jet 60, between those of Seyfert 1 and Seyfert 2/radio galaxies. These results confirm the possibility of Seyfert and radio galaxies sources are constituting a new class of gamma-ray source in the energy range E<sub>γ</sub> > 30 MeV.https://ojs.cvut.cz/ojs/index.php/APP/article/view/2376 |
| spellingShingle | Pieter J. Meintjes Pheneas Nkundabakura Brian van Soelen Alida Odendaal Modelling the Multifrequency SED of AGN Candidates among the Unidentied EGRET and Fermi Gamma-Ray Sources Acta Polytechnica CTU Proceedings |
| title | Modelling the Multifrequency SED of AGN Candidates among the Unidentied EGRET and Fermi Gamma-Ray Sources |
| title_full | Modelling the Multifrequency SED of AGN Candidates among the Unidentied EGRET and Fermi Gamma-Ray Sources |
| title_fullStr | Modelling the Multifrequency SED of AGN Candidates among the Unidentied EGRET and Fermi Gamma-Ray Sources |
| title_full_unstemmed | Modelling the Multifrequency SED of AGN Candidates among the Unidentied EGRET and Fermi Gamma-Ray Sources |
| title_short | Modelling the Multifrequency SED of AGN Candidates among the Unidentied EGRET and Fermi Gamma-Ray Sources |
| title_sort | modelling the multifrequency sed of agn candidates among the unidentied egret and fermi gamma ray sources |
| url | https://ojs.cvut.cz/ojs/index.php/APP/article/view/2376 |
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