Galaxy Groups and Clusters in the mini J-PAS survey: a Friends-of-Friends catalog

The catalogue was constructed by applying the Friends-of-Friends algorithm developed by Calvi et al. (2011) to the mini J-PAS survey (Bonoli et al. 2021). The initial detection was performed using a fixed projected radius of 0.5 comoving Mpc and a line-of-sight separation in photometric redshift space of 0.005(1+z), which corresponds to approximately 2000 km/s at z=0.3. Once the candidate structures were identified, the algorithm iteratively computed their virial radii and velocity dispersions, discarding interlopers at each step until convergence was reached. Using these initial parameters, the final catalogue comprises 274 groups and clusters, hosting a total of 1492 member galaxies. We limited our search to the redshift range 0.05 < z < 0.5 in this work. In the catalgue we report the group ID (an incremental number given by the code for identifying each object) in the first column, followed by the median RA and Dec (e.g. the group centre), the median redshift, velocity dispersion (in km/s), virial radius (Mpc), and number of member galaxies of each group.