Bibcode
López-Corredoira, Martín
Bibliographical reference
Journal of Astrophysics and Astronomy, vol. 28, issue 2-3, pp. 101-116
Advertised on:
10
2007
Citations
14
Refereed citations
12
Description
The Galactic foreground contamination in CMBR anisotropies, especially
from the dust component, is not easily separable from the cosmological
or extragalactic component. In this paper, some doubts will be raised
concerning the validity of the methods used to date to remove Galactic
dust emission in order to show that none of them achieves its goal.
First, I review the recent bibliography on the topic and discuss
critically the methods of foreground subtraction: the cross-correlation
with templates, analysis assuming the spectral shape of the Galactic
components, the "maximum entropy method", "internal linear combination",
and "wavelet-based high resolution fitting of internal templates".
Second, I analyse the galactic latitude dependence from WMAP data. The
frequency dependence is discussed with the data in the available
literature. The result is that all methods of subtracting the Galactic
contamination are inaccurate. The galactic latitude dependence analysis
or the frequency dependence of the anisotropies in the range 50-250 GHz
put a constraint on the maximum Galactic contribution in the power
spectrum to be less than a ~10% (68% C. L.) for a ~1 degree scale, and
possibly higher for larger scales. The origin of most of the signal in
the CMBR anisotropies is not Galactic. In any case, the subtraction of
the Galaxy is not accurate enough to allow a "precision Cosmology";
other sources of contamination (extragalactic, solar system) are also
present.