Parkes observations for project P1329 semester 2024OCTS_01

HI absorption studies are effective in probing the HI content in high redshift (z > 0.1) galaxies,
where HI emission is too faint to be detected. Although Ly alpha absorption can be used to probe the
HI at high redshift, it is difficult to carry out a blind Ly alpha absorption survey for galaxies at z <
1.65 where Ly alpha is not redshifted enough into optical window, to be observed with ground-based
optical telescopes. To date, there are about 150 associated HI absorption lines of which about one
third are at z < 0.1. In order to search for new HI absorption lines beyond local universe (z > 0.1),
we constructed a sample of 28 obscured sources with color of W2-W3 > 3. The observations are
expected to advance the understanding of HI content in this redshift range. Any detections of gas
inflow and outflow would also shed light on accretion and feedback of active galactic nuclei (AGN).
In total, we request 140 hours.