The large-scale structures (LSSs) that we see in our present Universe are the manifestation of primordial gravitational density fluctuations. The elements of the LSSs are - groups, clusters, filaments, walls, voids, and superclusters. The structures influence the properties of galaxies residing inside them. Deep and well-resolved observations in ultraviolet (UV) wavelength regimes are an excellent tool for probing recent ongoing star formation in galaxies. We investigate the star-forming properties of galaxies in z < 0.1 using UVIT Far-UV (FUV) imaging observations.

In the first part of my talk, I discuss the results from our study of filament galaxies based on the proposed UVIT observations. We do not detect FUV emission in galaxies within a radius of 0.4 Mpc from the filament axis. On comparing the FUV-specific star formation rate (sSFR) of filament galaxies to those in the cluster, we find that the sSFR of filament galaxies in a fixed stellar mass bin (M⋆ ∼ 10^11 M⊙) is higher than cluster galaxies. Our work highlights the difference in galaxy evolution in the two LSSs. In the second part, I present the results from our study of UV-substructures in early-type galaxies (ETGs). Such galaxies host a dominant fraction of the evolved stellar population. We compute non-parametric morphological parameters for optical and FUV imaging observations of ETGs. We find that irrespective of stellar mass or color of the ETGs, the clumpiness and asymmetry in FUV observations were higher by several orders than the optical counterpart. The result hints towards ubiquitous star formation in the ETGs.