J/A+A/691/A350 AGB stars with candidate WBS star companions (Magnus+, 2024)
Calibration of the JAGB method for the Magellanic Clouds and Milky Way from
Gaia DR3, considering the role of oxygen-rich AGB stars.
Magnus E., Groenewegen M.A.T., Girardi L., Pastorelli G., Marigo P.,
Boyer M.L.
<Astron. Astrophys. 691, A350 (2024)>
=2024A&A...691A.350M 2024A&A...691A.350M (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Magellanic Clouds ; Stars, double and multiple ;
Stars, giant ; Optical
Keywords: stars: AGB and post-AGB - stars: carbon - stars: distances -
stars: luminosity function, mass function - Magellanic Clouds
Abstract:
he JAGB method is a new way of measuring distances in the Universe
with the use of asymptotic giant branch (AGB) that are situated in a
selected region in a J versus J-Ks colour-magnitude diagram (CMD),
and relying on the fact that the absolute J magnitude is (almost)
constant. It is implicitly assumed in the method that the selected
stars are carbon-rich AGB stars (carbon stars). However, as the sample
selected to determine MJ is purely colour based, there can also be
contamination by oxygen-rich AGB stars in principle. As the ratio of
carbon-rich to oxygen-rich stars is known to depend on metallicity and
initial mass, the star formation history and age-metallicity
relation in a galaxy should influence the value of MJ. The aim of
this paper is to look at mixed samples of oxygen-rich and carbon-rich
stars for the Large Magellanic Cloud (LMC), Small Magellanic Cloud
(SMC), and Milky way (MW) using the Gaia catalogue of long-period
variables (LPVs) as a basis. The advantage of this catalogue is that
it contains a classification of O- and C-stars based on the analysis
of Gaia Rp spectra. The LPV catalogue is correlated with data from the
Two Micron All Sky Survey (2MASS) and samples in the LMC, SMC, and the
MW are retrieved. Following methods proposed in the literature, we
report the mean and median magnitudes of the selected sample using
different colour and magnitude cuts and the results of fitting
Gaussian and Lorentzian profiles to the luminosity function (LF). For
the SMC and LMC, we confirm previous results in the literature. The
LFs of the SMC and LMC JAGB stars are clearly different, yet it can be
argued that the mean magnitude inside a selection box agrees at the
0.021mag level. The results of our analysis of the MW sample are less
straightforward. The contamination by O-rich stars is substantial for
a classical lower limit of (J-Ks)0=1.3, and becomes less than 10%
only for (J-Ks)0=1.5. The sample of AGB stars is smaller than for
the MCs for two reasons. Nearby AGB stars (with potentially the best
determined parallax) tend to be absent as they saturate in the 2MASS
catalogue, and the parallax errors of AGB stars tend to be larger
compared to non-AGB stars. Several approaches have been taken to
improve the situation but finally the JAGB LF for the MW contains
about 130 stars, and the fit of Gaussian and Lorentzian profiles is
essentially meaningless. The mean and median magnitudes are fainter
than for the MC samples by about 0.4 mag which is not predicted by
theory. We do not confirm the claim in the literature that the
absolute calibration of the JAGB method is independent of metallicity
up to solar metallicity. A reliable calibration of the JAGB method at
(near) solar metallicity should await further Gaia data releases, or
should be carried out in another environment.
Description:
AGB stars with candidate wide binary systems (WBS) star companions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablee1.dat 154 65 WBS (wide binary systems) candidates
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
I/358 : Gaia DR3 Part 4. Variability (Gaia Collaboration, 2022)
Byte-by-byte Description of file: tablee1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- SID Gaia DR3 identification number of the AGB star
21- 25 F5.3 mas plx Parallax of AGB star (1)
27- 31 F5.3 mas e_plx Parallax error of AGB star (1)
33- 38 F6.2 mas/yr pmRA Proper motion along RA of AGB star (1)
40- 43 F4.2 mas/yr e_pmRA Proper motion along RA error of AGB star (1)
45- 50 F6.2 mas/yr pmDE Proper motion along DE of AGB star (1)
52- 55 F4.2 mas/yr e_pmDE Proper motion along DE error of AGB star (1)
57- 62 F6.2 --- GoF Goodness-of-fit of AGB star (1)
64- 68 F5.3 --- RUWE RUWE of AGB star (1)
70- 78 A9 --- Name Common name of AGB star
80- 98 I19 --- SID2 Gaia DR3 identification number of the
WBS candidate potential companion
100-104 F5.1 arcmin theta Distance of the companion to the target star
106-110 F5.3 mas plx2 Parallax of WBS candidate potential companion
112-116 F5.3 mas e_plx2 Parallax error of WBS candidate potential
companion
118-123 F6.2 mas/yr pmRA2 Proper motion along RA of WBS candidate
potential companion
125-128 F4.2 mas/yr e_pmRA2 Proper motion along RA error of WBS candidate
potential companion
130-135 F6.2 mas/yr pmDE2 Proper motion along DE of WBS candidate
potential companion
137-140 F4.2 mas/yr e_pmDE2 Proper motion along DE error of WBS candidate
potential companion
142-147 F6.2 --- GoF2 Goodness-of-fit of WBS candidate potential
companion
149-154 F6.3 --- RUWE2 RUWE of WBS candidate potential companion
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Note (1): from the LPV2 catalogue, Lebzelter et al., 2023A&A...674A..15L 2023A&A...674A..15L,
Cat. I/358, vlpv table.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 15-Apr-2025