EWOCS ongoing project: The search for the cluster MS turn-off

THIS PAGE WILL NOT BE UPDATED ANYMORE. PLEASE VISIT THE OFFICIAL EWOCS WEBSITE: https://westerlund1survey.wordpress.com/

The age is one of the fundamental parameters of Westerlund 1 that must be determined with high accurancy for its importance on several topics, going from simulations of cluster evolution and population synthesis, to the analysis of the evironmental feedback on protoplanetary disks evolution.

Several estimates of the cluster age exist in literature, determined with different methods and often resulting in discordant results. Estimates range from 3.2 Myrs (Brandner et al. 2008) to 10.4 Myrs (Beasor et al. 2021).

An accurate way to determine the cluster age is by finding its main-sequence turn-off, which is the mass at which massive stars have recently developed from the main-sequence to the following evolutionary stages. This is a quite complicated task since it requires the analysis of good-quality spectra in order to obtain accurate estimate of stellar properties.

To this aim, R. Castellanos and P. Najarro obtained K-MOS spectra of stars in Wd1. Data analysis is currently ongoing.