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Updated: Jul 18, 2026

Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating
Published on: October 11, 2016
Can the lumpy distribution of galaxies be reconciled with the smooth X-ray background?
1Department of Physics, University of California, San Diego, USA.
Abstract:
The fluctuations in X-ray background intensity that would be generated by clusters or superclusters of galaxies exceed those observed. It may be that the X-ray background arises from low-luminosity objects which are distributed much more smoothly and are more numerous than bright optical galaxies. Hierarchical universe models in which the distribution of X-ray sources follows the cosmological mass distribution are ruled out.
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