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School of Physics and Astronomy

Small-Scale CMB Cosmology: ACT, Planck and Beyond

4 June 2014

Time: 4:30pm
Venue: Maths 103

Series: The London Relativity and Cosmology Seminar
Speaker: Renee Hlozek (Princeton)
Abstract: The Atacama Cosmology Telescope (ACT) has mapped the microwave sky to arcminute scales. We present constraints on parameters from the observations at 148 and 217 GHz respectively by ACT from three years of observations. We fit a model of primary cosmological and secondary foreground parameters to the dataset, including contributions from both the thermal and kinetic Sunyaev-Zeldovich effect, Poisson distributed and correlated infrared sources, radio sources and a term modeling the correlation between the thermal SZ effect and the Cosmic Infrared Background. We will also put these results in context with the recent results from the Planck satellite, and discuss a reanalysis of the Planck data. We find that the 217GHz x 217GHz detector set spectrum used in the Planck analysis is responsible for some of the tension between the Planck parameters and other astronomical measurements. The difference in parameters between our analysis and that of the Planck team is mostly due to our use of cross-spectra from the publicly available survey maps instead of their use of the detector set cross-spectra which include pixels only observed in one of the surveys. We show evidence suggesting residual systematics in the detector set spectra used in the Planck likelihood code, which is substantially reduced for our spectra. We put these results in context of the recent BICEP results.