Substructures in Minor Mergers' Tidal Streams

International audienceIn this work, we explore the idea that substructures like stellar clusters could be formed from the tidal stream produced in galactic minor mergers. We use $N$-body and SPH simulations of satellite galaxies interacting with a larger galaxy. We study the distribution of mass in streams to identify overdensity regions in which a substructure could be formed. We found that without gas, no substructure formed as none of the overdensities shows a definite morphology nor dynamical stability. Including gas we found that several clumps appear and proved to be real long standing physical structures ($t \geq$ 1 Gyr). We analyzed the orbits, ages and masses of these structures, finding its correspondence with the halo subsystems. We conclude that it is possible to form cluster-like structures from the material in tidal streams and found evidence in favour of the presence of dark matter in these systems