CHILES XII: The H I evolution of Luminous Compact Blue Galaxies between 0<z<0.48

We study the evolution of Luminous Compact Blue Galaxies (LCBGs) by making use of H I emission line data provided by the full 856 h COSMOS H I Large Extragalactic Survey (CHILES), which spans a redshift range of $0\le z\le 0.48$ within the COSMOS field. We report the results on a cubelet stacking analysis, which we use to estimate the average H I mass evolution of LCBGs in the field up to $z=0.48$. For the stacks that do not show a detection, we report an upper limit estimate of the average H I mass. We also report on two directly detected LCBGs. We find the average H I mass in LCBGs at redshifts $z=0.26$, $z=0.35$ and $z=0.45$ respectively to be $⟨M_{\mathrm{H}\mathrm{I}}⟩<4.89\times {10}^9$ M${}_{\odot }$, $⟨M_{\mathrm{H}\mathrm{I}}⟩=(2.49\pm 0.75)\times {10}^9$ M${}_{\odot }$ and $⟨M_{\mathrm{H}\mathrm{I}}⟩=(6.44\pm 2.71)\times {10}^9$ M${}_{\odot }$. We see no strong evidence for evolution in the average H I mass over this redshift range, consistent with other recent studies of the evolution of the H I in galaxies at $z<0.5$. On average, LCBGs appear to retain substantial gas reservoirs, with gas fractions staying constant and remaining broadly consistent with those of the larger star-forming population. LCBG gas depletion timescales are nearly an order of magnitude shorter than in normal star-forming galaxies across the studied redshift range, aligning with the period during which their number density drops sharply.