J/A+A/707/A384 Evolutionary sequences of stars (Gavetti+, 2026)
An analysis of the JAGB method from the perspective of the asymptotic giant
branch evolution.
Gavetti C., Ventura P., Dell'Agli F., Correnti M., La Franca F.
<Astron. Astrophys. 707, A384 (2026)>
=2026A&A...707A.384G 2026A&A...707A.384G (SIMBAD/NED BibCode)
ADC_Keywords: Models, evolutionary ; Stars, giant ; Stars, masses ;
Effective temperatures ; Mass loss
Keywords: stars: AGB and post-AGB - stars: evolution -
stars: luminosity function, mass function -
stars: mass-loss -dust, extinction - distance scale
Abstract:
The JAGB method has been proposed over the last years as a possible
distance indicator for the galaxies in the Local Group and possibly
beyond. The nature of the stars populating the J region, as also the
conditions on the star formation history and on the structural
properties of the galaxies for the straight application of this method
need still to be investigated.
We studied the populations of the J region of the colour-magnitude
(J-K,J) plane of the Large and Small Magellanic Cloud (LMC and SMC,
respectively), to relate the shape of the J luminosity function (JLF)
to the details of the formation histories of the two galaxies, in the
attempt of distinguishing the general aspects of the JLF to those more
sensitive to the stellar population of the specific galaxy considered.
We used a population synthesis approach, based on the combined results
from stellar evolution and dust formation modelling, to find the
expected distribution of the stars within the J region, and compare it
with that derived from the observations of LMC and SMC stars. Some
physical assumptions, mostly related to the modelling of the red giant
branch and asymptotic giant branch phases of stars, are tuned, until
satisfactory agreement between the expectations from synthetic
modelling and the observational evidence is reached.
The sources observed within the J region are identified with stars
that have recently reached the C-star stage, and have not yet
accumulated the extremely large amounts of carbon required to make the
evolutionary track to evolve off the J region. Generally speaking,
2-3M☉ stars stay longer within the J region, while lower mass
objects evolve there for at most a couple of inter-pulse phases. The
analysis of the JLF of the LMC, peaked at the J magnitudes expected
for these stars, confirm this understanding. In the SMC the
distribution of the J fluxes is shifted to higher J magnitudes when
compared to the LMC, which we interpret as the signature of an average
older population, with smaller mass progenitors.
Description:
Each file reports the evolutionary track in e-AGB and AGB phases of a
stellar model of different masses (from to 0.6M☉ to 3M☉)
and metallicities (10-3, 4x10-3, 8x10-3). For each mass, the
physical properties of the star and the magnitudes in the J, H, K
bands are reported.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
060z1m3jhk.dat 91 62 M=0.60Msun, Z=0.001 evolutionary track
in e-AGB and AGB phases
070z1m3jhk.dat 90 75 M=0.70Msun, Z=0.001 evolutionary track
in e-AGB and AGB phases
080z1m3jhk.dat 88 87 M=0.80Msun, Z=0.001 evolutionary track
in e-AGB and AGB phases
090z1m3jhk.dat 88 72 M=0.90Msun, Z=0.001 evolutionary track
in e-AGB and AGB phases
090z4m3jhk.dat 88 107 M=0.90Msun, Z=0.004 evolutionary track
in e-AGB and AGB phases
090z8m3jhk.dat 88 119 M=0.90Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
100z1m3jhk.dat 88 86 M=1.00Msun, Z=0.001 evolutionary track
in e-AGB and AGB phases
100z4m3jhk.dat 88 117 M=1.00Msun, Z=0.004 evolutionary track
in e-AGB and AGB phases
100z8m3jhk.dat 88 131 M=1.00Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
110z4m3jhk.dat 88 107 M=1.10Msun, Z=0.004 evolutionary track
in e-AGB and AGB phases
110z8m3jhk.dat 88 117 M=1.10Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
125z4m3jhk.dat 88 118 M=1.25Msun, Z=0.004 evolutionary track
in e-AGB and AGB phases
125z8m3jhk.dat 88 123 M=1.25Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
150z4m3jhk.dat 88 126 M=1.50Msun, Z=0.004 evolutionary track
in e-AGB and AGB phases
150z8m3jhk.dat 88 131 M=1.50Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
175z4m3jhk.dat 88 150 M=1.75Msun, Z=0.004 evolutionary track
in e-AGB and AGB phases
175z8m3jhk.dat 88 152 M=1.75Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
200z4m3jhk.dat 88 237 M=2.00Msun, Z=0.004 evolutionary track
in e-AGB and AGB phases
200z8m3jhk.dat 88 248 M=2.00Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
250z4m3jhk.dat 88 158 M=2.50Msun, Z=0.004 evolutionary track
in e-AGB and AGB phases
250z8m3jhk.dat 88 252 M=2.50Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
300z4m3jhk.dat 88 135 M=3.00Msun, Z=0.004 evolutionary track
in e-AGB and AGB phases
300z8m3jhk.dat 88 152 M=3.00Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
350z8m3jhk.dat 88 363 M=3.50Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
400z4m3jhk.dat 88 398 M=4.00Msun, Z=0.004 evolutionary track
in e-AGB and AGB phases
400z8m3jhk.dat 88 376 M=4.00Msun, Z=0.008 evolutionary track
in e-AGB and AGB phases
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Byte-by-byte Description of file (#): *jhk.dat
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Bytes Format Units Label Explanations
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2- 11 E10.5 yr t(AGB) First 21 lines: time counted from the
exhaustion of central helium. Rest of the
lines: time counted from first thermal pulse
15- 18 F4.2 Msun Mass Evolving mass of the star
22- 30 E9.3 Lsun L Evolving luminosity of the star
33- 40 E8.3 Msun/yr Mdot Evolving mass-loss of the star
44- 50 F7.2 K Teff Evolving effective temperature of the star
54- 61 E8.3 --- CO Evolving C/O ratio of the star
65- 70 F6.3 mag 2MJ Evolving 2MJ band magnitude
74- 79 F6.3 mag 2MH Evolving 2MH band magnitude
83- 88 F6.3 mag 2MKs Evolving 2MKs band magnitude
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Acknowledgements:
Claudio Gavetti, claudio.gavetti(at)uniroma3.it
(End) Patricia Vannier [CDS] 02-Mar-2026