New PARSEC evolutionary tracks of massive stars at low metallicity: testing canonical stellar evolution in nearby star-forming dwarf galaxies

By Jing Tang, A. Bressan, P. Rosenfield, A. Slemer, P. Marigo, L. Girardi, L. Bianchi. 2014

322 citations recorded by the source corpus.

We extend the {\sl\,PARSEC} library of stellar evolutionary tracks by computing new models of massive stars, from 14\Msun to 350\Msun. The input physics is the same used in the {\sl\,PARSEC}~V1.1 version, but for the mass-loss rate which is included by considering the most recent updates in literature. We focus on low metallicity, $Z$=0.001 and $Z$=0.004, for which the metal poor dwarf irregular star forming galaxies, Sextans A, WLM and NCG6822, provide simple but powerful workbenches. The models reproduce fairly well the observed CMDs but the stellar colour distributions indicate that the predicted blue loop is not hot enough in models with canonical extent of overshooting. In the framework of a mild extended mixing during central hydrogen burning, the only way to reconcile the discrepancy is to enhance the overshooting at the base of the convective envelope (EO) during the first dredge-UP. The mixing scales required to reproduce the observed loops, EO=2\HP or EO=4\HP, are definitely larger than those derived from, e.g., the observed location of the RGB bump in low mass stars. This effect, if confirmed, would imply a strong dependence of the mixing scale below the formal Schwarzschild border, on the stellar mass or luminosity. Reproducing the features of the observed CMDs with standard values of envelope overshooting would require a metallicity significantly lower than the values measured in these galaxies. Other quantities, such as the star formation rate and the initial mass function, are only slightly sensitive to this effect. Future investigations will consider other metallicities and different mixing schemes.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/5f024093e6cc216470ca8c16fa4be6a170ca8a1e

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Citations in the corpus

The mass spectrum of compact remnants from the parsec stellar evolution tracks (2015, methodology): “Both the models of SN explosion (e.g. Fryer et al. 2012; Janka 2012; Burrows 2013; Clausen et al. 2015; Ertl et al. 2015; Pejcha & Prieto 2015) and the theory of massive star evolution (e.g. Bressan et al. 2012; Tang et al. 2014) were deeply revised in the last few years.”
The Lives of Stars: Insights from the TGAS–RAVE–LAMOST Data Set (2018, methodology): “An isochrone grid is constructed using the Padova isochrones4 (see Bressan et al. 2012, Chen et al. 2014, Chen et al. 2015, Tang et al. 2014).”
Merging black hole binaries with the SEVN code (2018, methodology): “In this respect, it is important to remind that the evolution of massive stars in the HR diagram, after central Hydrogen burning, strongly depends on the details of the input physics (Chiosi & Summa 1970; Tang et al. 2014).”
MESA ISOCHRONES AND STELLAR TRACKS (MIST). I. SOLAR-SCALED MODELS (2016, unknown): “2S (red; Bressan et al. 2012; Chen et al. 2014; Tang et al. 2014), Y2 (orange; Demarque et al. 2004), DSEP (green; Dotter et al. 2008), BaSTI “non-canonical” with η = 0.4 (turquoise; Pietrinferni et al. 2004), and Lyon (navy; Baraffe et al. 1998, 2003, 2015) for log(Age) [yr] = 7.5, 8.0, 9.0, and…”
Merging black hole binaries: the effects of progenitor's metallicity, mass-loss rate and Eddington factor (2017, methodology): “…(Ṁ ∝ Zα , with α ∼ 0.85, Vink et al. 2001, 2011; Muijres et al. 2012) not only during the main sequence (MS) but also after, including the Wolf-Rayet (WR) stage (see e.g. Vink & de Koter 2005; Meynet & Maeder 2005; Gräfener & Hamann 2008; Vink et al. 2011; Tang et al. 2014; Chen et al. 2015).”
A NEW GENERATION OF PARSEC-COLIBRI STELLAR ISOCHRONES INCLUDING THE TP-AGB PHASE (2017, background): “Such massive star models are described in Tang et al. (2014) and Chen et al. (2015), to whom we refer for all details.”
The biggest splash (2019, methodology): “The data were compared to a grid of PARSEC isochrone models (Bressan et al. 2012; Chen et al. 2014; Tang et al. 2014; Chen et al. 2015) in a probabilistic sense.”
The cosmic merger rate of stellar black hole binaries from the Illustris simulation (2017, methodology): “With this relatively small change, we obtain a mass spectrum of BHs similar to the one published by Spera et al. (2015) and based on the MNRAS 000, 000–000 (0000) PARSEC stellar evolution tracks (Bressan et al. 2012; Tang et al. 2014; Chen et al. 2015).”
Very massive stars, pair-instability supernovae and intermediate-mass black holes with the sevn code (2017, methodology): “The default version of SEVN includes a set of input tables generated using the PARSEC code (Bressan et al. 2012; Tang et al. 2014; Chen et al. 2015).”
Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18 (2019, methodology): “In this work we used a grid of PARSEC 1.2S stellar models (Bressan et al. 2012; Chen et al. 2014; Tang et al. 2014) in the 2MASS, Pan-STARRS1, Gaia DR2 rederived (Maíz Apellániz & Weiler 2018), and WISE photometric systems available on the CMD webpage maintained by L. Girardi5.”
Massive black hole binaries from runaway collisions: the impact of metallicity (2016, methodology): “Moreover, the evolutionary models of massive and very massive stars have been deeply revised in the last few years (e.g. Vink et al. 2001; Vink & de Koter 2005; Yungelson et al. 2008; Tang et al. 2014; Chen et al. 2015 and references therein).”
PARSEC evolutionary tracks of massive stars up to 350 M ☉ at metallicities 0.0001 ≤ Z ≤ 0.04 (2015, background): “A preliminary comparison of the new models with the colour-magnitude diagrams of star-forming regions in nearby low metallicity dwarf irregular galaxies, has already been performed in Tang et al. (2014).”
Dynamical modelling of the galactic bulge and bar: the Milky Way's pattern speed, stellar and dark matter mass distribution (2016, methodology): “…of every star using the surface gravity logg measurement obtained from fitting the spectra together with the PARSEC isochrones (Bressan et al. 2012; Chen et al. 2014; Tang et al. 2014) and assuming a 10Gyr old population, a Kroupa IMF and the overall metallicity distribution of all the ARGOS stars.”