Gravity Group Lunch Seminar, Anne Gambrel | KICP, U. Chicago "The XFaster Power Spectrum and Likelihood Estimator and its Application to SPIDER"

Nov 20, 2020, 12:00 pm12:00 pm
via Zoom


Event Description

Every analysis of cosmic microwave background observations faces the challenge of compressing large amounts of data into the comparatively tiny spaces of power spectra and cosmological parameters. A variety of pipelines have been used to accomplish this task, balancing the goals of optimally computing these quantities and their errors while requiring minimal computational cost. In this talk, I will introduce the XFaster pipeline, which estimates maximum likelihood bandpowers and their covariances quickly and with a relatively small ensemble of signal and noise simulations. XFaster has been used by the BOOMERanG and Planck experiments, and has been repackaged and extended for SPIDER. I will discuss the algorithm and the code, including new null test and foreground fitting features implemented for SPIDER. I will show the results of the extensive pipeline testing we have performed, and some results from its application to SPIDER data.