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Isolating the Foreground of the X-Ray Background

A. Refregier·D. J. Helfand·R. G. McMahon
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Abstract

The foreground component of the X-ray Background (XRB) can be studied by cross-correlating its intensity with galaxy catalogs. We computed the two-point cross-correlation function $W_{xg}$ between 67 {\em Einstein} X-ray fields and the APM galaxy catalog. We detected a signal with an amplitude of $W_{xg} = .04 \pm .01$, significant at the $3.5σ$ level. The reality of this signal was tested with a series of control data sets. We discuss how this signal can be used to constrain models of the XRB.

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A. Refregier, D. J. Helfand, R. G. McMahon. 1995-12-07. Isolating the Foreground of the X-Ray Background. https://arxiv.org/abs/astro-ph/9512042

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