Brown Dwarfs in the Pleiades, a deep IJK survey

An area large enough (180 sq arcmin) to put constraints on a possible low mass brown dwarf population in the Pleiades has been surveyed to very faint magnitudes in I, J and K. The completeness limit, I=21.6, corresponds to a mass of 0.01 Msun for a cluster age of 70 Myr and 0.035 Msun for 120 Myr. The result is consistent with previous investigations at higher masses that the brown dwarf initial mass function is a 1/m, or even less steep power law. Thus low mass brown dwarfs cannot contribute significantly to the Pleiades mass. One new possible Pleiades member was found, mass around 0.08 Msun.