A high-significance measurement of correlation between unresolved IRAS sources and optically-selected galaxy clusters
Abstract
We cross-correlate the 100 μm Improved Reprocessing of the IRAS Survey (IRIS) map and galaxy clusters at 0.1 < z < 0.3 in the maxBCG catalogue taken from the Sloan Digital Sky Survey, measuring an angular cross-power spectrum over multipole moments 150 < l < 3000 at a total significance of over 40σ. The cross-spectrum, which arises from the spatial correlation between unresolved dusty galaxies that make up the cosmic infrared background (CIB) in the IRIS map and the galaxy clusters, is well-fit by a single power law with an index of -1.28±0.12, similar to the clustering of unresolved galaxies from cross-correlating far-infrared and submillimetre maps at longer wavelengths. Using a recent, phenomenological model for the spectral and clustering properties of the IRIS galaxies, we constrain the large-scale bias of the maxBCG clusters to be 2.6±1.4, consistent with existing analyses of the real-space cluster correlation function. The success of our method suggests that future CIB-optical cross-correlations using Planck and Herschel data will significantly improve our understanding of the clustering and redshift distribution of the faint CIB sources.
- Publication:
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Journal of Cosmology and Astroparticle Physics
- Pub Date:
- May 2013
- DOI:
- 10.1088/1475-7516/2013/05/004
- arXiv:
- arXiv:1303.3272
- Bibcode:
- 2013JCAP...05..004H
- Keywords:
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- Astrophysics - Cosmology and Extragalactic Astrophysics
- E-Print:
- 14 pages, 4 figures