We report the first direct detection with Spitzer of galaxy filaments .
Using Spitzer and ancillary optical data , we have discovered two filamentary structures in the outskirts of the cluster Abell 1763 .
Both filaments point toward Abell 1770 which lies at the same redshift as Abell 1763 ( z = 0.23 ) , at a projected distance of \sim 13 Mpc .
The X-ray cluster emission is elongated along the same direction .

Most of the far-infrared emission is powered by star formation .
According to the optical spectra , only one of the cluster members is classified as an active galactic nucleus .
Star formation is clearly enhanced in galaxies along the filaments : the fraction of starburst galaxies in the filaments is more than twice than that in other cluster regions .
We speculate that these filaments are feeding the cluster Abell 1763 by the infall of galaxies and galaxy groups .
Evidence for one of these groups is provided by the analysis of galaxy kinematics in the central cluster region .