Probing Early Universe Cosmologies With SPIDER and Planck HFI

Abstract

We describe the design and characterization of the SPIDER balloon-borne experiment which will launch from Antarctica in December 2014. The experiment is designed to measure the polarization of the Cosmic Microwave Background (CMB) with unparalleled instantaneous sensitivity, and in doing so, constrain early universe models. The experiment is ready to deploy. We will emphasize: 1) The cryogenic architecture of the SPIDER flight cryostat. 2) The design and characterization of a capillary assembly which provides a continuous flow of superfluid helium to a 1.8 K temperature stage required to operate adsorption refrigerators cooling each focal plane. 3) The design and build of a Fourier transform spectrometer used to characterize the spectral response of the SPIDER detectors. 4) The optical characterization of the SPIDER telescopes and simulations characterizing susceptibility to polarized sidelobes contamination.

We also describe the analysis of the spatial (beam) response of the High Frequency Instrument (HFI) onboard the Planck satellite. This characterization work is required for high fidelity cosmological analysis of all-sky maps in six frequency bands spanning 100 to 857 GHz. The beam reconstruction error and bias are constrained using time-domain simulations that include the most significant non-idealities that affect the analysis. Using these simulations, we also verify the consistency of the beam product used for cosmological analysis of the 2014 data release. As part of the beam reconstruction, we characterize the flux of the five outer planets in the six HFI frequency bands. We also verify the absolute photometric calibration of the experiment by comparing planet flux estimates with existing models. Finally, we use planet flux measurements to show that the absolute calibrations of the WMAP and Planck experiments are consistent at the half percent level.