The role of the synchrotron component in the mid-infrared spectrum of M 87
We study in detail the mid-infrared (MIR) Spitzer-IRS spectrum of M 87 in the range 5–20 μm. Thanks to the high sensitivity of our Spitzer-IRS spectra we can disentangle the stellar and nuclear components of this active galaxy. To this end, we have properly subtracted from the M 87 spectrum the cont...
| Autores: | , |
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| Formato: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2009 |
| País: | México |
| Recursos: | Instituto Nacional de Astrofísica, Óptica y Electrónica |
| Repositorio: | Repositorio Institucional del INAOE |
| Idioma: | inglés |
| OAI Identifier: | oai:inaoe.repositorioinstitucional.mx:1009/1283 |
| Acesso em linha: | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1283 |
| Access Level: | acceso abierto |
| Palavra-chave: | info:eu-repo/classification/Inspec/Galaxies: active info:eu-repo/classification/Inspec/Galaxies: elliptical and lenticular, cD info:eu-repo/classification/Inspec/Galaxies: individual (M 87) info:eu-repo/classification/Inspec/Galaxies: jets info:eu-repo/classification/Inspec/Infrared: galaxies info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/21 |
| Resumo: | We study in detail the mid-infrared (MIR) Spitzer-IRS spectrum of M 87 in the range 5–20 μm. Thanks to the high sensitivity of our Spitzer-IRS spectra we can disentangle the stellar and nuclear components of this active galaxy. To this end, we have properly subtracted from the M 87 spectrum the contribution of the underlying stellar continuum derived from passive Virgo galaxies in our sample. The residual is a clear power law, without any additional termal component, with a zero-point consistent with that obtained by high spatial resolution, ground-based observations. The residual is independent of the adopted passive template. This indicates that the 10 μm silicate emission shown in the spectra of M 87 can be entirely accounted for by the underlying old stellar population, leaving little room for a possible torus contribution. The MIR power law has a slope α ∼0.77–0.82 (Sᵥ ∝ ν exp−α), consistent with optically thin synchrotron emission. |
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