Comparison of N-body simulations with Gaia DR3 data from OB associations

Abstract

Over the years, studies of OB associations have increased due to the fact that more massive stars allow for a better understanding of star formation. Thus, different simulations have been developed with the aim to better understand the main characteristics of these groups and to analyze the different theories about the formation of these associations. For this reason, in this work we have used N-body simulations, considering gas ejection, in order to compare the theoretical data with the observed data, specifically of the Vela OB2 association. For this purpose, 3 simulations were performed where a star formation efficiency of 0.1 and a fractal distribution were considered. In each simulation a stellar mass of $2500, 3000$ and $6000 M_{\odot}$ was considered. Then, as the cluster evolved, temperature and luminosity were obtained for each of the stars, and these values were transformed to obtain a Hertzsprung-Russell diagram to compare with the data obtained with Gaia DR3. It was found that at $10 Myr$, the data from the simulations vary quite a lot from the observational data when considering low mass stars, which could indicate that the bolometric correction applied to obtain the absolute magnitudes is giving values with quite large errors or it could also be due to the calculation of $G_{BP}-G_{RP}$ that is obtained with the temperatures of the stars.