The Star Formation History of Phoenix Dwarf Galaxy using IAC-pop Algorithm

The Star Formation History (SFH) of the Phoenix dwarf galaxy has been obtained using IAC-star and IAC-pop. The observations are based on WFPC2@HST. The results show a Star Formation Rate (SFR) decreasing with time and that star formation has happened in Phoenix up to 0.5 Gyr ago. The metallicity decrease with the stellar age: z>0.0007 for stars younger than 5 Gyr and z<0.0004 for stars older than 10 Gyr. Using the SFH as a function of galactocentric radius, the length scale α_N of the star density distribution profile has been obtained as a function of the time. The results show that α_N decreases smoothly with time, suggesting a sort of shrinking scenario for the evolution of Phoenix.