Fredagskollokvium: Unni Fuskeland: Foreground estimation - Cleaning up the CMB

In all data analysis it is important to have a good knowledge of all the components that contribute to the noise. This is of course also the case when analysing the cosmic microwave background radiation, CMB. One component of noise in the data is the so-called  foregrounds. It is radiation that the CMB detectors detect, but is not background radiation, for example radiation from our galaxy, radiation from supernova remnants and more. The main part of this talk will be to present two methods of estimating the foreground, with scatterplot and a maximum likelihood method. I will try to explain the methods in a basic way with examples from my analysis. Then I will show some of our results from the foreground analysis on WMAP 7year polarization data. Lastly, I will tell briefly about one other project which we have started doing. There is something called the "WMAP haze" which is an excess of microwave radiation in our galaxy center. It does not fit very well to be neither CMB, nor a standard foreground type. So one theory is that it could be synchrotron emission from particles produced in annihilation of a dark matter particle. Our method to investigate this is to use a template for dark matter in our galaxy center and treat it as a type of foreground in our CMB analysis.