Intensity mapping: a new approach to probe the large-scale structure of the universe

Abstract

HI intensity mapping (HI IM) is a new observational technique to survey the large-scale structure of the Universe using the 21 cm emission line of atomic hydrogen (HI). It can be used to constrain cosmological parameters, including the dark energy equation-of-state and the total mass of the neutrinos. This is exactly what the FAPESP-funded BAO from Integrated Neutral Gas Observations (BINGO) experiment will attempt to do in the near future. Observations of the HI signal will be contaminated by instrumental noise and, more significantly, by astrophysical foregrounds and systematics. The cleaning of these foregrounds and systematics is recognized as one of the key challenges for future radio astronomy surveys. In this project, we propose the investigation of the ability of the Generalized Needlet Internal Linear Combination (GNILC) method to subtract these foregrounds and systematics in several experimental conditions, such as in the presence of calibration errors and 1/f noise and in the reionization epoch, cases in which the method has not yet been tested. There are also several open questions about the use of the HI data in cosmological analyses: e.g., can the redshift-space distortion effect be observed and is there a way to optimize the detection of the BAO signal? We propose the investigation of these and other related questions to be a second line of research to be followed by the candidate in his postdoctoral. Moreover, we propose that the candidate get also involved in the development of methods and algorithms that will be needed for the appropriated analysis of the upcoming BINGO data. (AU)