Title: FAST HI Large Scale Survey

Speaker: Dr. Yi-Chao Li (Northeastern University)

Time: 10:00am, October 20, 2021

Location: 3-402, PMO Xianlin Campus

Abstract: Recently, the 21cm emission line of Neutral Hydrogen (HI) hyperfine spin-flip transition, has been proposed as another cosmological probe of the LSS. Instead of observing the HI emission line from individual galaxies, cosmologists proposed to measure the total HI intensity of the galaxies within large voxels, a technique known as HI intensity mapping (IM) The HI IM has been explored with a few different experiments, by measuring the cross-correlation function between HI IM survey and an optical galaxy survey. With a new generation of large radio telescopes, HI IM has been proposed as an important exploration for cosmology studies.

The FAST is ready for observation. With 300m effective aperture, the FAST is known to be a powerful equipment for HI IM. We proposed a pilot survey for HI IM and collected ~60hr observation time using FAST L-band multibeam receiver system, targeting at the SDSS field. We develop the data analysis pipeline for FAST HI drift-scan observation mode. With our pilot survey data, we are able to have a good understanding of the FAST receiver system and aim at a few science output, such as HI absorber searching, HI contents in Dwarf galaxies and cross-correlation with optical galaxy redshift survey.