Neutral Hydrogen Gas in Star Forming Galaxies at z=0.24

We use observations from the Giant Metrewave Radio Telescope (GMRT) to measure the atomic hydrogen gas content of star-forming galaxies at z = 0.24 (i.e. a look-backtime of ~3 Gyr). To measure the HI 21 cm emission signal we stack the signal from 121 galaxies with known optical positions and redshifts. We find an average HI mass for the galaxies of (2.26 ± 0.90) × 10⁹ M_⊙. We translate this HI measurement into a cosmic density of neutral gas at z=0.24 of Ω_gas = (0.91 ± 0.42) × 10⁻³. This value is consistent with that estimated from damped Lyα systems around this redshift.