Luminous x-ray agn in clusters of galaxies
We present a study of X-ray AGN overdensities in 16 Abell clusters, within the redshift range 0.073 < z < 0.279, in order to investigate the effect of the hot inter-cluster environment on the triggering of the AGN phenomenon. The X-ray AGN overdensities, with respect to the field expectations,...
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2010 |
| País: | México |
| Institución: | Instituto Nacional de Astrofísica, Óptica y Electrónica |
| Repositorio: | Repositorio Institucional del INAOE |
| Idioma: | inglés |
| OAI Identifier: | oai:inaoe.repositorioinstitucional.mx:1009/1541 |
| Acceso en línea: | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1541 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/Inspec/Galaxies: active info:eu-repo/classification/Inspec/Galaxies: clusters: general info:eu-repo/classification/Inspec/X-rays: galaxies info:eu-repo/classification/Inspec/X-rays: galaxies: clusters info:eu-repo/classification/Inspec/X-rays: general info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/21 |
| Sumario: | We present a study of X-ray AGN overdensities in 16 Abell clusters, within the redshift range 0.073 < z < 0.279, in order to investigate the effect of the hot inter-cluster environment on the triggering of the AGN phenomenon. The X-ray AGN overdensities, with respect to the field expectations, were estimated for sources with Lₓ≥ 10⁴² erg s⁻¹ (at the redshift of the clusters) and within an area of 1 h⁻¹₇₂ Mpc radius (excluding the core). To investigate the presence or not of a true enhancement of luminous X-ray AGN in the cluster area, we also derived the corresponding optical galaxy overdensities, using a suitable range of -band magnitudes. We always find the latter to be significantly higher (and only in two cases roughly equal) with respect to the corresponding X-ray overdensities. Over the whole cluster sample, the mean X-ray point-source overdensity is a factor of ~ 4 less than that corresponding to bright optical galaxies, a difference which is significant at a > 0.995 level, as indicated by an appropriate t-student test. We conclude that the triggering of luminous X-ray AGN in rich clusters is strongly suppressed. Furthermore, searching for optical Sloan Digital Sky Survey (SDSS) counterparts of all the X-ray sources, associated with our clusters, we found that about half appear to be background QSOs, while others are background and foreground AGN or stars. The true overdensity of X-ray point sources, associated to the clusters, is therefore even smaller than what our statistical approach revealed. |
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