2023/08/21 by C. Gordon, Gordon, Calum, Andrei Cuceu +115 · 3 citations
Physics and Astronomy · #Galaxies: Formation, Evolution, Phenomena #Radio Astronomy Observations and Technology #Scientific Research and Discoveries
paper · pdf · doi:10.48550/arxiv.2308.10950
We present the first measurements of Lyman-α (Lyα) forest correlations using early data from the Dark Energy Spectroscopic Instrument (DESI). We measure the auto-correlation of Lyα absorption using 88,509 quasars at z>2, and its cross-correlation with quasars using a further 147,899 tracer quasars at z\gtrsim1.77. Then, we fit these correlations using a 13-parameter model based on linear perturbation theory and find that it provides a good description of the data across a broad range of scales. We detect the BAO peak with a signal-to-noise ratio of 3.8σ, and show that our measurements of the auto- and cross-correlations are fully-consistent with previous measurements by the Extended Baryon Oscillation Spectroscopic Survey (eBOSS). Even though we only use here a small fraction of the final DESI dataset, our uncertainties are only a factor of 1.7 larger than those from the final eBOSS measurement. We validate the existing analysis methods of Lyα correlations in preparation for making a robust measurement of the BAO scale with the first year of DESI data.