Systematic effects in the extraction of the 'WMAP haze'

Journal Article · Fri Oct 01 04:00:00 EDT 2010 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2010/10/019· OSTI ID:22275350

Mertsch, Philipp; Sarkar, Subir ^[1]

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1. Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)

The extraction of a 'haze' from the WMAP microwave skymaps is based on subtraction of known foregrounds, viz. free-free (bremsstrahlung), thermal dust and synchrotron, each traced by other skymaps. While the 408 MHz all-sky survey is used for the synchrotron template, the WMAP bands are at tens of GHz where the spatial distribution of the radiating cosmic ray electrons ought to be quite different because of the energy-dependence of their diffusion in the Galaxy. The systematic uncertainty this introduces in the residual skymap is comparable to the claimed haze and can, for certain source distributions, have a very similar spectrum and latitudinal profile and even a somewhat similar morphology. Hence caution must be exercised in interpreting the haze as a physical signature of, e.g., dark matter annihilation in the Galactic centre.

• OSTI ID: 22275350
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 10 Vol. 2010; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANNIHILATION
ASTROPHYSICS
BREMSSTRAHLUNG
COMPARATIVE EVALUATIONS
COSMIC ELECTRONS
COSMOLOGY
ENERGY DEPENDENCE
GHZ RANGE
MHZ RANGE
MILKY WAY
NONLUMINOUS MATTER
RELICT RADIATION
SPATIAL DISTRIBUTION