Seminars
 
Global Hydrogen Cosmology Data Analysis for Rigorously Separating the Signal from Systematics
CSIC
 
Location
Sala Alberto Lobo (ICE building, UAB Campus)
Date
08/01/2020 - 00/00/0000
 
I will discuss our data analysis for sky-averaged 21-cm observations and the status of the experiments for which we are currently developing specific applications of this pipeline, the ground-based Cosmic Twilight Polarimeter (CTP) and the space-based Dark Ages Polarimeter PathfindER (DAPPER).

The first aims at independently validating the recent EDGES results, and the second at precision measurements of the Cosmic Dawn absorption trough plus the first detection of the purely cosmological Dark Ages trough at lower frequencies. For this, I will present how we self-consistently separate the signal from large systematics using a pattern recognition method based on training sets.

We then use the analytically calculated, spectral signal fit to start a Markov Chain Monte Carlo (MCMC) exploration of a nonlinear signal parameter space of choice. Efficiently, at each MCMC step, we marginalize over the weights of all linear beam-weighted foreground modes, allowing the complexity of the foreground model to be greatly increased without requiring additional MCMC parameters. We demonstrate the success of this methodology by recovering the input parameters from multiple randomly simulated signals (10-200 MHz), while rigorously accounting for realistically modeled foregrounds. Time permitting, I will also describe ongoing studies in which we benefit from our pipeline to both model foregrounds and implement two key experimental designs into our analysis, a time-series drift scan and induced polarization.
 
Attached Documents
Generalitat de CatalunyaUniversitat de BarcelonaUniversitat Autònoma de BarcelonaUniversitat Politècnica de CatalunyaConsejo Superior de Investigaciones CientíficasCentres de Recerca de Catalunya