According to a recent tweet by MNRAS & GJI, "PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code" is the most cited Monthly Notices of the Royal Astronomical Society’s paper of the last decade. This article, published in 2012 and coauthored by Alessandro Bressan, Paola Marigo, Léo Girardi, Bernardo Salasnich, Claudia Dal Cero, Stefano Rubele and Ambra Nanni, describes our new stellar evolution code and offers useful tools and related stellar deliverables to the observational and theoretical astronomical communities.
Thanks to PARSEC, it is possible to model the evolution of stars during the main central nuclear burning stages, for a wide range of stellar masses, between 0.1 and 500 solar masses, and for various chemical compositions ranging from the primordial mixture to super-solar cases, in which the abundances of heavy metals exceed several times the solar ones. The code is the result of a long-standing collaboration among researchers at INAF, SISSA and the University of Padova, with the contribution of several Master Degree and PhD students. “Once the models are computed and tested” Alessandro Bressan explains “they are shared with the entire astrophysical community through our public websites”.
Bressan says: “The PARSEC stellar models have proved to be appreciated worldwide for several reasons, most likely for their robustness, completeness and user-friendliness of our databases. They are widely used in many astrophysical contexts to infer or predict the properties of individual stars or resolved stellar populations (e.g. ages, masses, surface abundances), to analyze the integrated properties of more distant galaxies (e.g. with population synthesis and spectral evolution tools) and more recently to test the combined effects of stellar evolution and dynamics in the predicted mass spectrum of compact objects. Thanks to our students the PARSEC code has been continuously maintained and expanded to include the most updated input physics and successfully applied to investigate many current open problems in stellar and galaxy evolution. Finally, we wish to mention here that this work could not be possible without the contribution of external groups who provide essential ingredients, such as nuclear reactions rates (e.g. JINA Reaclib Database), gas opacities (Opacity Project At Livermore and AESOPUS at Padova), and equation of state (FREEOS, Irwin).
Andrea Lapi, Head of Astrophysics and Cosmology Group and Coordinator Ph.D. Astrophysics and Cosmology at SISSA, comments: "This amazing achievement once more testifies the high-quality standards of the research conducted in SISSA Astrophysics and Cosmology group. It also highlights the relevance of the recent developments in stellar astrophysics, a classic field that is still extremely fertile and capable of providing crucial inputs for forefront research in galaxy formation and evolution, gravitational wave astronomy, cosmology, and fundamental Physics."