Galaxy Transformation Across the Cosmic Web: Evolution of Stellar Colours and Star Formation Rates in Filaments

Abstract: Galaxies form and evolve within the diverse environments of the cosmic web. However, disentangling the effects of internal properties, local environments, and large-scale structures (LSS) on galaxy evolution involvessignificant complexities, since these effects are frequently overlapping. The aim of this work is to provide evidence of the imprints left by LSS on galaxy properties by selecting samples of galaxies from different environments, while matching their intrinsic characteristics. We investigate the effects of the LSS on the g-r colour and star formation rate (SFR) in galaxies with stellar mass M $> 10^{10}$ M$_\odot$, with the redshift $0.05 \le z \le 0.1$, and selected from the SDSS DR16. We use a catalogue of the LSS available in the literature to define samples of galaxies located in field and filament environments. Galaxies located in the field tend to exhibit bluer g-r stellar colours and higher SFR than those in filaments. These differences persist even in samples of galaxies matched by mass and galaxy local overdensity, indicating that they are not produced by internal processes. These differences cannot be attributed to variations in morphology. There is also a variation in stellar colour and SFR with distance to the filaments (Df). The SFR of galaxies becomes statistically smaller than that of field galaxies for objects located at Df<5 Mpc, while changes in stellar colour occur at smaller distances (Df<1 Mpc). This could indicates that the typical filament width is about 2.5-5 Mpc. The variations in colour and SFR between galaxy samples in the field and in filaments, with matched masses and local overdensities, indicate that large-scale environmental factors drive these transformations rather than local or internal galaxy properties. These transformations are not strong enough to produce changes in galaxy morphology. They could be explained by cosmic web starvation.