Open AccessThe cross‐correlation between the microwave and X‐ray backgrounds: foregrounds and systematics
Author(s) -
Boughn S. P.,
Crittenden R. G.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.09090.x
Subject(s) - physics , cmb cold spot , cosmic microwave background , astrophysics , cosmic background radiation , universe , amplitude , dark matter , dimensionless quantity , x ray background , astronomy , quasar , anisotropy , galaxy , quantum mechanics , mechanics
Recently, we presented evidence for a cross‐correlation of the WMAP satellite map of the cosmic microwave background (CMB) and the HEAO1 satellite map of the hard X‐ray background (XRB) with a dimensionless amplitude of 0.14 ± 0.05 normalized to the product of the rms fluctuations of the CMB and XRB. Such a correlation is expected in a universe dominated by a cosmological constant via the integrated Sachs–Wolfe (ISW) effect and the level of the correlation observed is consistent with that predicted by the currently favoured Lambda cold dark matter model of the Universe. As this offers independent confirmation of the cosmological model, it is important to verify the origin of the correlation. Here we explore in detail some possible foreground sources of the correlation. The present evidence all supports an ISW origin.