tailieunhanh - Báo cáo hóa học: " Adapted Method for Separating Kinetic SZ Signal from Primary CMB Fluctuations"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Adapted Method for Separating Kinetic SZ Signal from Primary CMB Fluctuations | EURASIP Journal on Applied Signal Processing 2005 15 2413-2425 2005 Hindawi Publishing Corporation Adapted Method for Separating Kinetic SZ Signal from Primary CMB Fluctuations Olivier Forni IAS-CNRS Universite Paris Sud Bailment 121 91405 Orsay Cedex France Email Nabila Aghanim IAS-CNRS Universite Paris Sud Batiment 121 91405 Orsay Cedex France Email Division of Theoretical Astronomy National Astronomical Observatory of Japan Osawa 2-21-1 Mitaka Tokyo 181-8588 Japan Received 30 May 2004 Revised 11 December 2004 In this first attempt to extract a map of the kinetic Sunyaev-Zel dovich KSZ temperature fluctuations from the cosmic microwave background CMB anisotropies we use a method which is based on simple and minimal assumptions. We first focus on the intrinsic limitations of the method due to the cosmological signal itself. We demonstrate using simulated maps that the KSZ reconstructed maps are in quite good agreement with the original input signal with a correlation coefficient between original and reconstructed maps of on average and an error on the standard deviation of the reconstructed KSZ map of only 5 on average. To achieve these results our method is based on the fact that some first-step component separation provides us with i a map of Compton parameters for the thermal Sunyaev-Zel dovich TSZ effect of galaxy clusters and ii a map of temperature fluctuations which is the sum of primary CMB and KSZ signals. Our method takes benefit from the spatial correlation between KSZ and TSZ effects which are both due to the same galaxy clusters. This correlation allows us to use the TSZ map as a spatial template in order to mask in the CMB KSZ map the pixels where the clusters must have imprinted an SZ fluctuation. In practice a series of TSZ thresholds is defined and for each threshold we estimate the corresponding KSZ signal by interpolating the CMB fluctuations on the masked pixels. The series of .