Evolutionary tracks, ejecta, and ionizing photons from intermediate-mass to very massive stars with PARSEC

TL;DR

This paper presents a comprehensive set of updated stellar evolution models across a wide range of metallicities and masses, providing insights into stellar fates, remnant masses, chemical yields, and ionizing photon production, with implications for understanding massive stars and black hole formation.

Contribution

The paper introduces a new, extensive grid of stellar evolution models using the updated PARSEC V2.0 code, covering a broad parameter space with improved physics and detailed outputs.

Findings

Remnant mass spectrum includes a black hole pair-instability gap between 100-130 M_sun.

Models align with observed black hole masses from GW190521, Cygnus X-1, and Gaia BH3.

Tracks successfully reproduce the properties of most massive stars in the Tarantula Nebula.

Abstract

Recent advancements in stellar evolution modeling offer unprecedented accuracy in predicting the evolution and deaths of stars. We present new stellar evolutionary models computed with the updated PARSEC V2.0 code for a comprehensive and homogeneous grid of metallicities and initial masses. Nuclear reaction networks, mass loss prescriptions, and the treatment of elemental mixing have all been updated in PARSEC V2.0. We computed models for thirteen initial metallicities spanning $Z = 10^{-11}$ to $Z = 0.03$, with masses ranging from 2.0 M$_{\odot}$ to 2000 M$_{\odot}$, consisting of a library of over 1,100 ($\sim 2100$ tracks including pure-He models) full stellar evolution tracks. For each track, the evolution is followed from the pre-main-sequence to the most advanced early-asymptotic-giant-branch or the pre-supernova phases, depending on the stellar mass. Here, we describe the properties of the tracks and their chemical and structural evolution. We computed the final fates and the remnant masses and built the mass spectrum for each metallicity, finding that the combined black hole (BH) pair-instability mass gap spans just between 100 and 130 M$_{\odot}$. Moreover, the remnant masses provide models consistent with observed BH masses, such as those from the primaries of GW190521, Cygnus X-1, and $\textit{Gaia}$ BH3 binary systems. We computed and provided the chemical ejecta from stellar winds and explosive final fates, along with the ionizing photon rates. Our results show strong overall consistency with other tracks computed with different codes. A comparison with a large sample of observed massive stars in the Tarantula Nebula of the Large Magellanic Cloud shows that our tracks nicely reproduce the majority of stars that lie on the main sequence. All the models are publicly available and can be retrieved on the PARSEC database.