2025MNRAS.540L..65B

We characterize the rest-frame 1500 Å UV luminosity function (UVLF) from deep AstroSat/UV Imaging Telescope (UVIT) F154W and N242W imaging in the Great Observatories Origins Survey South (GOODS-S) deep field. The UVLFs are constructed and subsequently characterized with fitted Schechter function parameters from Far-UV (FUV) observations at $z<0.13$ and Near-UV (NUV) observations in seven redshift bins in z $\sim$ 0.8-0.4. The UVLF slope ($\alpha$) and characteristic magnitude ($M^{*}$) are consistent with previous determinations for this redshift range based on AstroSat/UVIT GOODS-North observations, as well as with those from Galaxy evolution Explorer and Hubble Space Telescope observations. However, differences in the normalization factor ($\phi _{*}$) are present for UVLFs for some redshift bins. We compute the UV luminosity density, $\rho _{\rm UV}$, combining our determined UVLF parameters with literature determinations out to $z\sim 10$. The $\rho _{\rm UV}$ trend with redshift implies the rapid increase in cosmic star formation till its peak at $z\sim 3$ (cosmic noon) followed by a slow decline till present day. Both the initial increase in cosmic star formation and subsequent decline are found to be more rapid than previous determinations.