Gravitational lensing as a possible explanation for some unidentified gamma-ray sources at high latitudes
We propose that some of the high-latitude unidentified EGRET γ-ray sources could be the result of gravitational lensing amplification of the innermost regions of distant, faint, active galactic nuclei. These objects have γ-ray-emitting regions small enough to be affected by microlensing of stars in...
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2002
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v569_n2I_p600_Torres http://hdl.handle.net/20.500.12110/paper_0004637X_v569_n2I_p600_Torres |
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paper:paper_0004637X_v569_n2I_p600_Torres2023-06-08T14:28:44Z Gravitational lensing as a possible explanation for some unidentified gamma-ray sources at high latitudes Galaxies: active Gamma rays: observations Gravitational lensing We propose that some of the high-latitude unidentified EGRET γ-ray sources could be the result of gravitational lensing amplification of the innermost regions of distant, faint, active galactic nuclei. These objects have γ-ray-emitting regions small enough to be affected by microlensing of stars in interposed galaxies. We compute the gravitational amplification, taking into account effects of the host galaxy of the lens, and prove that, whereas the innermost γ-ray regions can be magnified up to a thousand times, there is no amplification at radio frequencies, which leads to the observed absence of strong counterparts. Some new effects in the spectral evolution of a gravitational microlensed γ-ray active galactic nuclei are predicted. Within a reasonable range of lensing parameters and/or types of sources, both variable and nonvariable EGRET detections at high latitudes can be explained by microlensing. The same phenomenon could also have an important incidence among the future GLAST detections at high latitudes. 2002 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v569_n2I_p600_Torres http://hdl.handle.net/20.500.12110/paper_0004637X_v569_n2I_p600_Torres |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Galaxies: active Gamma rays: observations Gravitational lensing |
| spellingShingle |
Galaxies: active Gamma rays: observations Gravitational lensing Gravitational lensing as a possible explanation for some unidentified gamma-ray sources at high latitudes |
| topic_facet |
Galaxies: active Gamma rays: observations Gravitational lensing |
| description |
We propose that some of the high-latitude unidentified EGRET γ-ray sources could be the result of gravitational lensing amplification of the innermost regions of distant, faint, active galactic nuclei. These objects have γ-ray-emitting regions small enough to be affected by microlensing of stars in interposed galaxies. We compute the gravitational amplification, taking into account effects of the host galaxy of the lens, and prove that, whereas the innermost γ-ray regions can be magnified up to a thousand times, there is no amplification at radio frequencies, which leads to the observed absence of strong counterparts. Some new effects in the spectral evolution of a gravitational microlensed γ-ray active galactic nuclei are predicted. Within a reasonable range of lensing parameters and/or types of sources, both variable and nonvariable EGRET detections at high latitudes can be explained by microlensing. The same phenomenon could also have an important incidence among the future GLAST detections at high latitudes. |
| title |
Gravitational lensing as a possible explanation for some unidentified gamma-ray sources at high latitudes |
| title_short |
Gravitational lensing as a possible explanation for some unidentified gamma-ray sources at high latitudes |
| title_full |
Gravitational lensing as a possible explanation for some unidentified gamma-ray sources at high latitudes |
| title_fullStr |
Gravitational lensing as a possible explanation for some unidentified gamma-ray sources at high latitudes |
| title_full_unstemmed |
Gravitational lensing as a possible explanation for some unidentified gamma-ray sources at high latitudes |
| title_sort |
gravitational lensing as a possible explanation for some unidentified gamma-ray sources at high latitudes |
| publishDate |
2002 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v569_n2I_p600_Torres http://hdl.handle.net/20.500.12110/paper_0004637X_v569_n2I_p600_Torres |
| _version_ |
1768544345743425536 |