The mass function of NGC288

Abstract

We present NICMOS NIC3 observations of the Galactic globular cluster NGC 288, taken South - East at 2.4 times the cluster&#39;s half-light radius in the J and H bands. We have detected the cluster main sequence down to J~25 and H~24. The corresponding luminosity function covers the range 3<M_H<9 and peaks at M_H~6.8. The theoretical tracks of Baraffe et al. (1997) at [Fe/H]=-1.3 give a mass function which is best fitted by a log-normal distribution with characteristic mass m_c=0.42 Msolar and a standard deviation sigma=0.35. This result is fully consistent with the global mass function derived by Paresce & De Marchi (2000) for a sample of 12 globular clusters with very different dynamical histories, thus confirming that near the cluster&#39;s half-light radius the mass function appears ``undistorted&#39;&#39; by evaporation or tidal interactions with the Galaxy and should then reflect the initial mass function.