Clumps and satellites impact on galaxy mass

Prompted by these observations and by the comparison with simulations, we suggest that compact blobs are in situ formed clumps, whereas the extended ones are accreting satellites. Clumps and satellites enclose, respectively, ~20 per cent and ~<80 per cent of the galaxy stellar mass, ~30 per cent and ~20 per cent of its star formation rate. Considering the compact blobs, we statistically estimated that massive clumps (M_{*}_>~10^9^M_{sun}_) have lifetimes of ~650Myr, and the less massive ones (10^8^< M_{*}_<10^9^M_{sun}_) of ~145Myr.

This supports simulations predicting long-lived clumps (lifetime >~100Myr). Finally, ~<30 per cent (13 per cent) of our sample galaxies are undergoing single (multiple) merger(s), they have a projected separation ~<10kpc, and the typical mass ratio of our satellites is 1:5 (but ranges between 1:10 and 1:1), in agreement with literature results for close pair galaxies.