Analysis validation of the Lyman-alpha forest measurements from the Dark Energy Spectroscopic Instrument

by César Ramírez Pérez (IFAE)

Friday 13 Sep 2024, 11:00 → 13:00 Europe/Madrid

IFAE Seminar Room (Hybrid)

Supervisor: Andreu Font Ribera

 

Abstract:

    In recent decades, advances in galaxy surveys have significantly enhanced our ability to study the universe's composition and evolution, particularly the elusive dark energy. While galaxy surveys have traditionally been the usual way of studying the distribution of matter, in this thesis I have made important contributions to the development of an alternative probe: the Lyman-alpha forest.

    The Lyman-alpha forest is a pattern of absorption features in the spectra of distant quasars caused by intervening neutral hydrogen. The Dark Energy Spectroscopic Instrument (DESI) survey will measure the spectra of up to 3 million quasars, providing the best measurement of the universe's expansion to date using the Lyman-alpha forest.

    My contributions to this survey include the creation of the first Lyman-alpha catalog using the Early Data Release from the survey. And the analysis valiation using data from Data Release 1.

    To aid in the development of cosmological surveys, synthetic datasets are used to help build analysis pipelines, estimate covariance matrices, and perform forecasting. In this thesis I present CoLoRe, a code for synthetic data generation for multiple tracers, including the Lyman-alpha forest. This code allows for the generation of random data from multiple state-of-the-art surveys in the same realisation, enabling the study of the interplay between them.