Abstract details

I will critically review the different methods used to assess the key factor in the fitting of colour-magnitude diagrams (CMDs): the goodness of fit between observed and synthetic realisations of CMDs. Using extensive Markov Chain Monte Carlo techniques, I will provide a detailed insight into the advantages and pitfalls of each method used, along with the biases and (part of) the systematic errors produced. I will then present a new statistical technique which is shown to be optimal and which avoids most previous limitations, and will apply it to the analysis of stellar populations in nearby, resolved galaxies, revisiting their star formation histories. Next, I will show the extension of the method to the case of stellar populations in pixels of distant galaxies, assessing the limitations of the method, and applying it to ACS/HST observations of galaxies over a wide range of redshifts.