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 \sim 1000 massive ( M _ { \star } \gtrsim 2 \times 10 ^ { 11 } M _ { \odot } ) visually classified elliptical galaxies down to a satellite mass ratio of 1:400 ( i.e .
5 \times 10 ^ { 8 } \lesssim M _ { sat } \lesssim 2 \times 10 ^ { 11 } M _ { \odot } ) .
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 \sim 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 \sim 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 ) .