J/A+A/679/A137 Very massive star models (VMS) (Martinet+, 2023)
Very massive star models.
I. Impact of rotation and metallicity and comparisons with observations
Martinet S., Meynet G., Ekstrom S., Georgy C., Hirschi R.
<Astron. Astrophys. 679, A137 (2023)>
=2023A&A...679A.137M 2023A&A...679A.137M (SIMBAD/NED BibCode)
ADC_Keywords: Models, evolutionary ; Stars, masses ; Abundances
Keywords: stars: evolution - stars: massive - stars: rotation -
stars: Wolf-Rayet - stars: mass-loss - stars: Population III
Abstract:
In addition to being spectacular objects, very massive stars (VMSs)
are suspected to have a tremendous impact on their environment and on
cosmic evolution in general. The nucleosynthesis both during their
advanced stages and their final explosion may contribute greatly to
the overall enrichment of the Universe. Their resulting supernovae are
candidates for the most superluminous events possible and their
extreme conditions also lead to very important radiative and
mechanical feedback effects, from local to cosmic scale.
We explore the impact of rotation and metallicity on the evolution of
very massive stars across cosmic times.
With the recent implementation of an equation of state in the GENEC
stellar evolution code, appropriate for describing the conditions in
the central regions of very massive stars in the advanced phases, we
present new results on VMS evolution from Population III to solar
metallicity.
Low metallicity VMS models are highly sensitive to rotation, while the
evolution of higher metallicity models is dominated by mass loss
effects. The mass loss affects strongly their surface velocity
evolution, breaking quickly at high metallicity while reaching the
critical velocity for low metallicity models. The comparison to
observed VMS in the LMC shows that the mass loss prescriptions used
for these models are compatible with observed mass loss rates. In our
framework for modelling rotation, our models of VMS need a high
initial velocity to reproduce the observed surface velocities. The
surface enrichment of these VMS is difficult to explain with only one
initial composition, and could suggest multiple populations in the
R136 cluster. At a metallicity typical of R136, only our non- or
slowly rotating VMS models may produce Pair Instability supernovae.
The most massive black holes that can be formed are less massive than
about 60M☉.
Direct observational constraints on VMS are still scarce. Future
observational campaigns will hopefully gather more pieces of
information to guide the theoretical modeling of these objects, whose
impacts can be very important.
Description:
Models of non-rotating and rotating VMS at Z=0, 10e-5, 0.006 and 0.014.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 58 18 List of model grids
tables/* . 18 Individual model grids
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Zini Initial metallicity Z
11- 22 A12 --- Mini Initial mass model
24- 35 A12 ---- Rot Rotating or non-rotating (Rot04 for V/Vc=0.4)
37- 58 A22 --- FileName Name of the model grid in subdirectory tables
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Byte-by-byte Description of file (#): tables/*
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Bytes Format Units Label Explanations
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1- 3 I3 --- Line Sequential number
6- 27 E22.16 yr Time Time age
28- 38 F11.6 Msun Mass Mass
40- 48 F9.6 [Lsun] log(L) Luminosity
50- 58 F9.6 [K] log(Teff) Effective temperature
61- 73 E13.8 --- 1Hsurf H surface abundance (mass fraction)
76- 88 E13.8 --- 4Hesurf 4He surface abundance
(mass fraction)
91-103 E13.8 --- 12Csurf 12C surface abundance
(mass fraction)
106-118 E13.8 --- 13Csurf 13C surface abundance
(mass fraction)
121-133 E13.8 --- 14Nsurf 14N surface abundance
(mass fraction)
136-148 E13.8 --- 16Osurf 16O surface abundance
(mass fraction)
151-163 E13.8 --- 17Osurf 17O surface abundance
(mass fraction)
166-178 E13.8 --- 18Osurf 18O surface abundance
(mass fraction)
181-193 E13.8 --- 20Nesurf 20Ne surface abundance
(mass fraction)
196-208 E13.8 --- 22Nesurf 22Ne surface abundance
(mass fraction)
211-219 E9.4 --- 26Alsurf 26Al surface abundance
(mass fraction)
221-227 F7.4 --- Mcc/Mt Convective core to total mass ratio
230-237 F8.6 [K] log(Teff)2 Effective temperature (repeated)
241-246 F6.3 [Msun/yr] log(dM/dt) Mass loss rate
249-256 F8.6 [g/cm3] log(rhoc) Central density
259-266 F8.6 [K] log(Tc) Central temperature
268-281 E14.8 --- 1Hcen H central abundance (mass fraction)
284-296 E13.8 --- 4Hecen 4He central abundance
(mass fraction)
299-311 E13.8 --- 12Ccen 12C central abundance
(mass fraction)
314-326 E13.8 --- 13Ccen 13C central abundance
(mass fraction)
329-341 E13.8 --- 14Ncen 14N central abundance
(mass fraction)
344-356 E13.8 --- 16Ocen 16O central abundance
(mass fraction)
359-371 E13.8 --- 17Ocen 17O central abundance
(mass fraction)
374-386 E13.8 --- 18Ocen 18O central abundance
(mass fraction)
389-401 E13.8 --- 20Necen 20Ne central abundance
(mass fraction)
404-416 E13.8 --- 22Necen 22Ne central abundance
(mass fraction)
419-427 E9.4 --- 26Alcen 26Al central abundance
(mass fraction)
430-438 E9.4 rad/s Omegsurf Surface angular velocity ωs
441-449 E9.4 rad/s Omegcen Central angular velocity ωc
452-460 E9.4 --- Rp/Req Oblatness (Rpol/Req)
463-471 E9.4 --- Md/Md(0) Rotational dM/dt correction factor
474-481 E8.3 km/s vcrit1 First critical velocity
484-491 E8.3 km/s vcrit2 Second critical velocity
494-501 E8.3 km/s vequa Equatorial velocity
504-511 F8.6 --- Om/Omc ωs/ωc
514-521 F8.6 --- GammaEd Eddington factor Gammma
523-536 E14.8 [Msun/yr] log(dMm/dt) Mechanical equatorial mass loss dM/dt
539-554 E16.12 [10-53g.cm2/s] Ltot Total angular momentum
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Acknowledgements:
Sebastien Martinet, sebastien.martinet(at)ulb.be
(End) Patricia Vannier [CDS] 09-Nov-2023