J/A+A/682/A123 Convective-core overshooting of massive stars (Temaj+, 2024)
Convective-core overshooting and the final fate of massive stars.
Temaj D., Schneider F.R.N., Laplace E., Wei D., Podsiadlowski P.
<Astron. Astrophys. 682, A123 (2024)>
=2024A&A...682A.123T 2024A&A...682A.123T (SIMBAD/NED BibCode)
ADC_Keywords: Models, evolutionary ; Supernovae ; Abundances
Keywords: stars: black holes - stars: general - stars: massive -
stars: neutron - supernovae: general
Abstract:
Understanding and predicting their final fate is increasingly
important, e.g., in the context of gravitational-wave astronomy. The
interior mixing of stars in general and convective boundary mixing in
particular remain some of the largest uncertainties in their
evolution. Here, we investigate the influence of convective boundary
mixing on the pre-supernova structure and explosion properties of
massive stars. Using the 1D stellar evolution code Mesa, we model
single, non-rotating stars of solar metallicity with initial masses of
5-70M☉ and convective core step-overshooting of 0.05-0.50
pressure scale heights. Stars are evolved until the onset of iron core
collapse, and the pre-SN models are exploded using a parametric,
semi-analytic SN code. We use the compactness parameter to describe
the interior structure of stars at core collapse and find a pronounced
peak in compactness at carbon-oxygen core masses of MCO∼7M☉ and
generally high compactness at MCO≳14M☉. Larger convective
core overshooting shifts the location of the compactness peak by
1-2M☉ to higher MCO. These core masses correspond to initial
masses of 24M☉ (19M☉) and ≳40M☉ (≳30M☉),
respectively, in models with the lowest (highest) convective core
overshooting parameter. In both high-compactness regimes, stars are
found to collapse into black holes. As the luminosity of the
pre-supernova progenitor is determined by MCO, we predict blackhole
formation for progenitors with luminosities
5.35≤log(L/L☉)≤5.50 and log(L/L☉)≥5.80. The luminosity
range of black-hole formation from stars in the compactness peak
agrees well with the observed luminosity of the red supergiant star
N6946 BH1 that disappeared without a bright supernova and likely
collapsed into a black hole. While some of our models in the
luminosity range log(L/L☉)=5.1-5.5 indeed collapse to form black
holes, this does not fully explain the lack of observed SN IIP
progenitors at these luminosities, i.e. the missing red-supergiant
problem. The amount of convective boundary mixing also affects the
wind mass loss of stars such that the lowest black hole mass are
15M☉ and 10M☉ in our models with the lowest and highest
convective core overshooting parameter, respectively. The compactness
parameter, central specific entropy, and iron core mass describe a
qualitatively similar landscape as a function of MCO, and we find
that entropy is a particularly good predictor of the neutron-star
masses in our models. We find no correlation between the explosion
energy, kick velocity, and nickel mass production with the convective
core overshooting value, but a tight relation with the compactness
parameter. We further show how convective core overshooting affects
the pre-supernova locations of stars in the Hertzsprung-Russell
diagram and the plateau luminosity and duration of SN IIP lightcurves.
Description:
Properties of all our models used throughout the paper. Explosion
properties of models that were not computed to core-collapse are
empty. We give the initial masses Mini, convective core overshooting
values αov, helium-core masses MHe, CO-core masses MCO,
iron-core masses MFe, carbon abundance at the end of core-helium
burning XC, final mass of the models Mfinal, compactness value
χ2.5, central specific entropy at the onset of iron-core collapse
sc, the gravitational binding energy of the material above the iron
core -Ebind, the predicted final fate, the gravitational remnant
masses Mrm, explosion energy Eexpl, kick velocity vkick, nickel mass
MNi, ejecta mass Mej, plateau luminosity Lp/Lp,0, duration of the
plateau tp/tp,0, luminosity at the end of core-helium burning logLc
and the effective temperature at the end of core-helium burning
logTeff.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 112 250 Properties of all our models used throughout
the paper
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 F4.1 Msun Mini Initial mass
6- 9 F4.2 --- alphaov Convective core overshooting value
11- 15 F5.2 Msun MHe Helium-core mass
17- 21 F5.2 Msun MCO ?=- CO-core mass
23- 26 F4.2 Msun MFe ?=- Iron-core mass
28- 31 F4.2 --- Xc ?=- Carbon abundance at the end of
core-helium burning
33- 37 F5.2 Msun Mfinal Final mass of the model
39- 42 F4.2 --- chi2.5 ?=- Compactness value χ25
44- 47 F4.2 --- Sc ?=- Central specific entropy at the onset
of iron-core collapse
49- 53 F5.2 10-7J mEbind ?=- Gravitational binding energy of the
material above the iron core (-Ebind)
55- 61 A7 --- Fate Predicted final fate
63- 67 F5.2 Msun Mrm ?=- Gravitational remnant mass
69- 72 F4.2 10+44J Eexpl ?=- Explosion energy
(in units of Bethe, 1051erg)
74- 80 F7.2 km/s vkick ?=- Licl velocity
82- 85 F4.2 Msun MNi ?=- Nickel mass
87- 91 F5.2 Msun Mej ?=- Ejecta mass
93- 96 F4.2 --- Lp/Lp0 ?=- Plateau luminosity Lp/Lp,0
98-101 F4.2 --- tp/tp0 ?=- Duration of the plateau tp/tp,0
103-107 F5.2 [Lsun] LogLc Luminosity at the end of core-helium burning
109-112 F4.2 [K] logTeff Effective temperature at the end of
core-helium burning
--------------------------------------------------------------------------------
Acknowledgements:
Duresa Temaj, duresa.temaj(at)gmail.com
(End) Patricia Vannier [CDS] 13-Nov-2023