Title: Deep HST observations of Palomar 5 and its tidal tails

Abstract:
We will present early results from the analysis of our multi-cycle HST program on Palomar 5 
and its tidal tails. We quantify the stellar populations in one of the densest regions of Pal5 
trailing tidal tail. From deep CMD analysis we measure the mass function and total mass for the 
first time with such a depth within a tidal stream. When combined with wide-field data like 
SDSS, we are able to estimate the mass loss rate of Pal5. Moreover, we set empirical 
constraint to the distance gradient along Palomar 5’s trailing tail via isochrone fitting. These 
results are valuable constraints for dynamical models and help us to understand cluster mass 
loss driven by two body relaxation and tidal shocks, as it can be directly compared to high-
precision N-body simulations.