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arXiv · astro-ph/9707135

Fluctuations in the diffuse X-ray background observed with Ginga

J. A. Butcher·G. C. Stewart·R. S. Warwick·A. C. Fabian·F. J. Carrera·X. Barcons·K. Hayashida·H. Inoue·T. Kii
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Abstract

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 N - log S relation in the 2-10 keV energy band to a form close to the Euclidean prediction over the flux range 1E-10 - 5E-13 erg/cm2/s. The normalisation of the 2-10 keV source counts is a factor 2-3 above that derived in the softer 0.3-3.5 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. L_X < 1E44 erg/s) 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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J. A. Butcher, G. C. Stewart, R. S. Warwick, A. C. Fabian, F. J. Carrera, X. Barcons, K. Hayashida, H. Inoue, T. Kii. 1997-07-12. Fluctuations in the diffuse X-ray background observed with Ginga. https://doi.org/10.1093/mnras%2F291.3.437

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