Evolutionary sequences of stars

The nature of the stars populating the J region, as also the conditions on the star formation history and on the structural properties of the galaxies for the straight application of this method need still to be investigated. We studied the populations of the J region of the colour-magnitude (J-K,J) plane of the Large and Small Magellanic Cloud (LMC and SMC, respectively), to relate the shape of the J luminosity function (JLF) to the details of the formation histories of the two galaxies, in the attempt of distinguishing the general aspects of the JLF to those more sensitive to the stellar population of the specific galaxy considered.

We used a population synthesis approach, based on the combined results from stellar evolution and dust formation modelling, to find the expected distribution of the stars within the J region, and compare it with that derived from the observations of LMC and SMC stars. Some physical assumptions, mostly related to the modelling of the red giant branch and asymptotic giant branch phases of stars, are tuned, until satisfactory agreement between the expectations from synthetic modelling and the observational evidence is reached.