J/A+A/697/A114 New empirical mass-loss recipe for hot stars (Pauli+, 2025)
New empirical mass-loss recipe for UV radiation line-driven winds of hot stars
across various metallicities.
Pauli D., Oskinova L.M., Hamann W.-R., Sander A.A.C., Vink J.S.,
Bernini-Peron M., Josiek J., Lefever R.R., Sana H., Ramachandran V.
<Astron. Astrophys. 697, A114 (2025)>
=2025A&A...697A.114P 2025A&A...697A.114P (SIMBAD/NED BibCode)
ADC_Keywords: Stars, OB ; Stars, Wolf-Rayet ; Stars, masses ; Mass loss
Keywords: stars: atmospheres - stars: early-type - stars: evolution -
stars: massive - stars: mass-loss - stars: winds, outflows
Abstract:
The winds of massive stars remove a significant fraction of their
mass, strongly impacting their evolution. As a star evolves, the rate
at which it loses mass changes. In stellar evolution codes, different
mass-loss recipes are employed for different evolutionary stages. The
choice of the recipes is user-dependent and the conditions for
switching between them are poorly defined. Focusing on hot stars, we
aim to produce a physically motivated, empirically calibrated
mass-loss recipe suitable for a wide range of metallicities. We want
to provide a ready-to-use universal recipe that eliminates the need
for switching between recipes for hot stars during stellar evolution
calculations. We compile a sample of hot stars with reliable stellar
and wind parameters in the Galaxy and the Magellanic Clouds. Our
sample spans effective temperatures from T~=12kK-100kK and initial
masses from Mini~=15M☉ to 150M☉. The sample is used to
determine the dependence of the mass-loss rate on the basic stellar
parameters. We find that independent of evolutionary stage and
temperature, the wind mass-loss rate is a function of the
electron-scattering Eddington parameter ({GAMMA}e) and metallicity
(Z), being in line with expectations of radiation-driven wind theory.
Our derived scaling relation provides an adequate
({DELTA}log((dM/dt)/(M☉/yr))=0.43) and broadly applicable
mass-loss recipe for hot stars. The newly derived mass-loss recipe
covers nearly the entire parameter space of hot stars with UV
radiation-driven winds and eliminates the need for interpolation
between mass-loss formulae at different evolutionary stages when
applied in stellar evolution models. Examples of stellar evolution
calculations using our new recipe reveal that the predictions on the
ionizing fluxes and final fates of massive stars, especially at low
metallicity, differ significantly from models that use the standard
mass-loss rates, impacting our understanding of stellar populations at
low metallicity and in the young Universe.
Description:
We collected stellar and wind parameters of 188 different stars
in the Galaxy and Magellanic clouds as presented in various literature
studies. Here we provide tables listing the stellar and wind
parameters of all stars used in this work.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 88 104 Stellar and wind parameters of OB stars with
surface gravities below log(g/(cm/s2))<3.8
tablea2.dat 79 6 Stellar and wind parameters of partially
stripped stars
tablea3.dat 89 24 Stellar and wind parameters of WR binaries
tablea4.dat 62 12 Stellar and wind parameters of [WR] stars
tablea5.dat 81 61 Stellar and wind parameters of OB stars with
surface gravities above log(g/(cm/s2))≥ 3.8
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Byte-by-byte Description of file: tablea1.dat tablea2.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Name of star as used in the analysis paper
15- 18 F4.1 kK T Temperature
20- 23 F4.2 [Lsun] logL Luminosity
25- 28 F4.2 [cm/s2] logg Surface Gravity
30- 32 I3 km/s vsini Projected rotational velocity
34- 38 F5.1 Msun Mass Mass (calculated using log(g) corrected for
the centrifugal force)
40- 43 F4.2 --- XH Surface hydrogen mass-fraction
45- 49 F5.2 --- logGammae Electron-scattering Eddington factor
51- 55 F5.2 [Msun/yr] logdM/dt Mass loss rate
57- 59 A3 --- Galaxy [GAL LMC SMC] Host Galaxy
61- 86 A26 --- Ref ADS bibcode of the analysis paper
88 I1 --- Note [1]? 1 = Mass-loss rate corrected for a
clumping factor of D=10
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Name of star as used in the analysis paper
12- 16 F5.1 kK T Temperature
18- 21 F4.2 [Lsun] logL Luminosity
23- 25 I3 Msun Morb Orbital mass (1)
27- 30 F4.2 --- XH Surface hydrogen mass-fraction
32- 36 F5.2 --- logGammae Electron-scattering Eddington factor
38- 42 F5.2 [Msun/yr] logdM/dt Mass loss rate
44- 46 A3 --- Galaxy [GAL LMC SMC] Host Galaxy
48- 87 A40 --- Ref ADS bibcode of the analysis paper
89 I1 --- Note [1]? 1 = We assumed an inclination of
i=59.7deg to match the spectroscopic mass
(corrected for the centrifugal force) of
the OB star with the orbital mass
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Note (1): Note that when the inclination is unknown, it is typically estimated
by matching the secondary's spectroscopic mass to the orbital one. For more
details, we refer to the individual papers.
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Byte-by-byte Description of file: tablea4.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Name of star as used in the analysis paper
10- 12 I3 kK T Temperature
14- 17 F4.2 [Lsun] logL Luminosity
19- 21 F3.1 Msun Mass Mass (1)
23- 26 F4.2 --- XH Surface hydrogen mass-fraction
28- 32 F5.2 --- logGammae Electron-scattering Eddington factor
34- 38 F5.2 [Msun/yr] logdM/dt Mass loss rate
40- 42 A3 --- Galaxy [GAL] Host Galaxy
44- 62 A19 --- Ref ADS bibcode of the analysis paper
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Note (1): For [WR] stars no spectroscopic mass can be derived. Model
calculations predict that these objects have masses between 0.4M_☉
to 0.8M_☉ (Tylenda 2003IAUS..209..159T 2003IAUS..209..159T). For simplicity the average mass
of 0.6M☉ is assumed. Note that these stars are not included in the
fitting routine due to this uncertainty.
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Byte-by-byte Description of file: tablea5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Name of star as used in the analysis paper
15- 18 F4.1 kK T Temperature
20- 23 F4.2 [Lsun] logL Luminosity
25- 28 F4.2 [cm/s2] logg Surface Gravity
30- 32 I3 km/s vsini Projected rotational velocity
34- 38 F5.1 Msun Mass Mass (calculated using log(g) corrected for
the centrifugal force)
40- 43 F4.2 --- XH Surface hydrogen mass-fraction
45- 49 F5.2 --- logGammae Electron-scattering Eddington factor
51- 55 F5.2 [Msun/yr] logdM/dt Mass loss rate
57- 59 A3 --- Galaxy [GAL LMC SMC] Host Galaxy
61- 79 A19 --- Ref ADS bibcode of the analysis paper
81 I1 --- Note [1]? 1 = Mass-loss rate corrected for a
clumping factor of D=10
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Acknowledgements:
Daniel Pauli, daniel.pauli(at)kuleuven.be
(End) Patricia Vannier [CDS] 07-Apr-2025