Fossil group origins

Aims. We analyse the large-scale structure out to 100 Mpc around a sample of 16 confirmed fossil systems using spectroscopic information from Sloan Digital Sky Survey Data Release 16. Methods. computed distance between our groups (FGs) and centres filaments nodes literature. also studied density bright galaxies, since this parameter is thought be good mass tracers, as well projected over-densities galaxies. Finally, we applied friends-of-friends (FoF) algorithm detect virialised structures FGs obtain an estimate available in their surroundings. Results. find that are mainly located close filaments, with mean 3.7 ± 1.1 R 200 minimum 0.05 . On other hand, none were found intersections, 19.3 3.6 6.1 , respectively. There correlation indicates at higher redshifts denser regions, when use galaxies tracers mass. At same time, largest magnitude gaps (? m 12 > 2.5) less dense environments tend host (on average) smaller central Conclusions. Our results suggest formed peculiar position within cosmic web, far nodes, whereby interaction web itself may limited. deduce brightest (BCGs) relatively faint, high values ? low could, fact, very last stage evolution. Moreover, confirm theoretical predictions gap not massive.