Abstract Details
| Name: A Pavan Kumar Affiliation: IUCAA, Pune Conference ID: ASI2015_759 Title : Recovering hidden signals of anisotropy from CMB maps and trist with mask Authors and Co-Authors : Nidhi Pant, Aditya Rotti, Tarun Souradeep Abstract Type : Poster Abstract Category : General Relativity and Cosmology Abstract : Any isotropy violating phenomena on CMB, such as low-l hemispherical power asymmetry, local motion, lensing, etc, induces subtle off-diagonal correlations in the two-point function, which can be used to independently estimate these anisotropic signals themselves. We developed an estimation procedure based on the bipolar shperical harmonic (BipoSH) formalism, which allows a complete description of two-point correlation function on a sphere. To avoid biases due to foreground contamination, omitting (masking) regions of the CMB sky where the reconstruction is unreliable is a conventional practice in CMB analyses. Partial sky survey also leads to a similar situation as masking. Masking or availability of partial sky complicates the recovery, and is accute for estimating a subtle signal such as Doppler boost. In this work, we demonstrate that the effects of masking, and any spurious correlations thus induced can be comprehensively addressed within the BipoSH framework to successfully recover hidden signals of anisotropy in observed CMB maps. This method is generic, and can be applied to variety of isotropy violating signals. We specifically discuss recovery of Doppler boost of CMB and low-l hemisphrical power asymmtery which is phenomenologically modeled as dipole modulation of CMB anisotropies. |