We present a statistical study of the filamentary structures of the Cosmic Web in the large hydro-dynamical simulations TNG300-1 and MAGNETICUM at redshift z = 0 .
We focus on the radial distribution of the galaxy density around filaments detected using the Discrete Persistent Structure Extractor ( DisPerSE ) .
We show that the average profile of filaments presents an excess of galaxy density ( > 5 \sigma ) up to radial distances of 27 Mpc from the core .
The relation between galaxy density and the length of filaments is further investigated showing that short ( L _ { \mathrm { f } } < 9 Mpc ) and long ( L _ { \mathrm { f } } \geq 20 Mpc ) filaments are two statistically different populations .
Short filaments are puffier , denser and more connected to massive objects , whereas long filaments are thinner , less dense and more connected to less massive structures .
These two populations trace different environments and may correspond to bridges of matter between over-dense structures ( short filaments ) and to the cosmic filaments shaping the skeleton of the Cosmic Web ( long filaments ) .
Through MCMC explorations , we find that the density profiles of both short and long filaments can be described by the same empirical models ( GNFW , \beta -model , a single and a double power law ) with different and distinct sets of parameters .