Using the spectroscopic New York University Value-Added Galaxy Catalogue and the photometric photo-z catalogues of the Sloan Digital Sky Survey Data Release 7, we have explored the satellite distribution around ∼1000 massive (M ⋆ 2×10 11 M ⊙ ) visually classified elliptical galaxies down to a satellite mass ratio of 1:400 (i.e. 5×10 8 M sat 2×10 11 M ⊙ ). Our host galaxies were selected to be representative of a mass complete sample. The satellites of these galaxies were searched within a projected radial distance of 100 kpc to their hosts. We have found that only 20-23 per cent of the massive ellipticals have at least a satellite down to a mass ratio 1:10. This number increases to 45-52 per cent if we explore satellites down to 1:100 and is >60-70 per cent if we go further down to 1:400. The average projected radial distance of the satellites to their hosts for our whole sample down to 1:400 is ∼59 kpc (which can be decreased at least down to 50 kpc if we account for incompleteness effects). The number of satellites per galaxy host only increases very mildly at decreasing the satellite mass. The fraction of mass which is contained in the satellites down to a mass ratio of 1:400 is 8 per cent of the total mass contained by the hosts. Satellites with a mass ratio from 1:2 to 1:5 (with ∼28 per cent of the total mass of the satellites) are the main contributor to the total satellite mass. If the satellites eventually infall into the host galaxies, the merger channel will be largely dominated by satellites with a mass ratio down to 1:10 (as these objects have 68 per cent of the total mass in satellites).

Using the spectroscopic catalogue of the Sloan Digital Sky Survey Data Release 10, we have explored the abundance of satellites around a sample of 254 massive (10 11 < M ⋆ <2×10 11 M ⊙ ) local (z < 0.025) galaxies. We have divided our sample into four morphological groups (E, S0, Sa, Sb/c). We find that the number of satellites with M ⋆ 10 9 M ⊙ and R<300 kpc depends drastically on the morphology of the central galaxy. The average number of satellites per galaxy host (N Sat /N Host ) down to a mass ratio of 1:100 is: 4.5 ± 0.3 for E hosts, 2.6 ± 0.2 for S0, 1.5 ± 0.1 for Sa and 1.2 ± 0.2 for Sb/c. The amount of stellar mass enclosed by the satellites around massive E-type galaxies is a factor of 2, 4 and 5 larger than the mass in the satellites of S0, Sa and Sb/c-types, respectively. If these satellites would eventually infall into the host galaxies, for all the morphological types, the merger channel will be largely dominated by satellites with a mass ratio satellite-host µ >0.1. The fact that massive elliptical galaxies have a significant larger number of satellites than massive spirals could point out that elliptical galaxies inhabit heavier dark matter haloes than equally massive galaxies with later morphological types. If this hypothesis is correct, the dark matter haloes of late-type spiral galaxies are a factor of ∼2-3 more efficient on producing galaxies with the same stellar mass than those dark matter haloes of early-type galaxies.