Foreground Subtraction of Cosmic Microwave Background Maps using WI-FIT (Wavelet based hIgh resolution Fitting of Internal Templates)

Details Foreground Subtraction of Cosmic Microwave Background Maps using WI-FIT (Wavelet based hIgh resolution Fitting of Internal Templates) Foreground Subtraction of Cosmic Microwave Background Maps using WI-FIT (Wavelet based hIgh resolution Fitting of Internal Templates)

2006-03-13

arxiv.org/abs/astro-ph/0603308v1

Astrophys.J.648:784-796,2006

Astronomy and Astrophysics

Astrophysics

Submitted to ApJ

Scientific paper

10.1086/506015

We present a new approach to foreground removal for Cosmic Microwave Background (CMB) maps. Rather than relying on prior knowledge about the foreground components, we first extract the necessary information about them directly from the microwave sky maps by taking differences of temperature maps at different frequencies. These difference maps, which we refer to as internal templates, consist only of linear combinations of galactic foregrounds and noise, with no CMB component. We obtain the foreground cleaned maps by fitting these internal templates to, and subsequently subtracting the appropriately scaled contributions of them from, the CMB dominated channels. The fitting operation is performed in wavelet space, making the analysis feasible at high resolution with only a minor loss of precision. Applying this procedure to the WMAP data, we obtain a power spectrum that matches the spectrum obtained by the WMAP team at the signal dominated scales. Finally, we have revisited previous claims about a north-south power asymmetry on large angular scales, and confirm that these remain unchanged with this completely different approach to foreground separation. This also holds when fitting the foreground contribution independently to the northern and southern hemisphere indicating that the asymmetry is unlikely to have its origin in different foreground properties of the hemispheres. This conclusion is further strengthened by the lack of any observed frequency dependence.

Affiliated with

Also associated with

No associations

Rating

Foreground Subtraction of Cosmic Microwave Background Maps using WI-FIT (Wavelet based hIgh resolution Fitting of Internal Templates) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Foreground Subtraction of Cosmic Microwave Background Maps using WI-FIT (Wavelet based hIgh resolution Fitting of Internal Templates), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Foreground Subtraction of Cosmic Microwave Background Maps using WI-FIT (Wavelet based hIgh resolution Fitting of Internal Templates) will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-704220