The NuSTAR view of the true type 2 Seyfert NGC 3147
We present the first NuSTAR observation of a 'true' type 2 Seyfert galaxy. The 3-40 keV X-ray spectrum of NGC 3147 is characterized by a simple power-law, with a standard γ ~ 1.7 and an iron emission line, with no need for any further component up to ~40 keV. These spectral properties, tog...
| Autores: | , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/170133 |
| Acceso en línea: | http://hdl.handle.net/10261/170133 |
| Access Level: | acceso abierto |
| Palabra clave: | X-rays: individual: NGC 3147 Galaxies: Seyfert Galaxies: active |
| Sumario: | We present the first NuSTAR observation of a 'true' type 2 Seyfert galaxy. The 3-40 keV X-ray spectrum of NGC 3147 is characterized by a simple power-law, with a standard γ ~ 1.7 and an iron emission line, with no need for any further component up to ~40 keV. These spectral properties, together with significant variability on time-scales as short as weeks (as shown in a 2014 Swift monitoring campaign), strongly support an unobscured line of sight for this source. An alternative scenario in terms of a Compton-thick source is strongly disfavoured, requiring an exceptional geometrical configuration, whereas a large fraction of the solid angle to the source is filled by a highly ionized gas, whose reprocessed emission would dominate the observed luminosity. Moreover, in this scenario, the implied intrinsic X-ray luminosity of the source would be much larger than the value predicted by other luminosity proxies, like the [OIII ]λ5007 emission-line extinction-corrected luminosity. Therefore, we confirm with high confidence that NGC 3147 is a true type 2 Seyfert galaxy, intrinsically characterized by the absence of a broad-line region. |
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