Fluctuations in the diffuse X-ray background observed with Ginga
We present Ginga measurements of the spatial fluctuations in the diffuse X-ray background. When combined with earlier results, the new data constrain the extragalactic log M-log S relation in the 2-10 keV energy band to a form close to the Euclidean prediction over the flux range 10-10-5 × 10-13 erg...
| Autores: | , , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1997 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/169768 |
| Acesso em linha: | http://hdl.handle.net/10261/169768 |
| Access Level: | acceso abierto |
| Palavra-chave: | Galaxies: active X-ray general Diffuse radiation |
| Resumo: | We present Ginga measurements of the spatial fluctuations in the diffuse X-ray background. When combined with earlier results, the new data constrain the extragalactic log M-log S relation in the 2-10 keV energy band to a form close to the Euclidean prediction over the flux range 10-10-5 × 10-13 erg cm-2 s-1. The normalization of the 2-10 keV source counts is a factor 2-3 above that derived in the softer 0.3-0.5 keV band from the Einstein Extended Medium Sensitivity Survey, if a spectral conversion is assumed which ignores X-ray absorption intrinsic to the sources. Both this result and the spectral characteristics of the spatial fluctuations are consistent with relatively low-luminosity active galaxies (i.e. Lx< 1044 erg s-1) dominating the 2-10 keV source counts at intermediate flux levels. We also use the 'excess variance' of the fluctuations to constrain possible clustering of the underlying discrete sources. |
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