Speaker
Description
Dark Energy Spectroscopic Instrument (DESI) is the first on-going Stage IV spectroscopic redshift survey, covering a wide sky area and redshift range. As one of the key goals, DESI will measure the Baryon Acoustic Oscillations (BAO) from different tracers, including BGS, LRG, ELG and QSO at different redshifts. The density field reconstruction is significantly important to reduce the systematics and to improve the precision for the BAO scale measurement. To support the DESI key project on BAO, we study the optimal reconstruction schemes for different DESI tracers. We utilize the first generation of DESI mocks which are based on the AbacusSummit simulation and calibrated from the SV3 DESI data. Based on the realistic mocks, we perform the standard BAO reconstruction using two reconstruction algorithms, i.e. MultiGrid and IterativeFFT, which are implemented in the DESI package pyrecon. For each algorithm, we study the case which removes or contains the redshift space distortion in the reconstructed field, respectively. Varying the density smoothing parameter, we study the systematic influence in detail on the propagator, the reconstructed power spectrum and correlation function, as well as the BAO scale parameters. Our work contributes significantly to the DESI pipeline for the BAO measurement. In my talk, I will mainly show the reconstruction for LRG.
