J/ApJS/258/43 Light curves of AGBs in Galactic open clusters (Marigo+, 2022)
A fresh look at AGB stars in Galactic open clusters with Gaia:
impact on stellar models and the initial-final mass relation.
Marigo, P., Bossini D., Trabucchi M., Addari F., Girardi L., Cummings J.,
Pastorelli G., Dal Tio P., Costa G., Bressan A.
<Astrophys. J. Suppl. Ser. 258, 43 (2022)>
=2022ApJS..258...43M 2022ApJS..258...43M (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, late-type ; Stars, variable ; Photometry
Keywords: open star clusters - asymptotic giant branch stars - carbon stars -
long period variable stars - stellar winds - circumstellar dust -
stellar evolution
Abstract:
Benefiting from the GAIA second and early third releases of
photometric and astrometric data we examine the population of
asymptotic giant branch (AGB) stars that appear in the fields of
intermediate-age and young open star clusters. We identify 49 AGB star
candidates, brighter than the tip of the red giant branch, with a
good-to-high cluster membership probability. Among them we find 19
TP-AGB stars with known spectral type: 4 M stars, 3 MS/S stars and 12
C stars. By combining observations, stellar models, and radiative
transfer calculations that include the effect of circumstellar dust,
we characterize each star in terms of initial mass, luminosity,
mass-loss rate, core mass, period and mode of pulsation. The
information collected helps us shed light on the TP-AGB evolution at
solar-like metallicity, placing constraints on the third dredge-up
process, the initial masses of carbon stars, stellar winds, and the
initial-final mass relation (IFMR). In particular, we find that two
bright carbon stars, MSB 75 and BM IV 90, members of the clusters NGC
7789 and NGC 2660 (with similar ages of about 1.2-1.6 Gyr and initial
masses between 2.1 and 1.9 solar masses), have unusually high core
masses, about 0.67-0.7 solar masses. These results support the
findings of a recent work (Marigo et al., 2020NatAs...4.1102M 2020NatAs...4.1102M) that
identified a kink in the IFMR, which interrupts its monotonic trend
just at the same initial masses. Finally, we investigate two competing
scenarios to explain the Mc data: the role of stellar winds in
single-star evolution, and binary interactions through the
blue-straggler channel.
Description:
We searched for photometric time series for the AGB star candidates we
studied among the public data from three ongoing time-domain astronomy
surveys, namely Gaia (DR2, Holl et al., 2018A&A...618A..30H 2018A&A...618A..30H, Cat.
345), the All-Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et
al. 2014, AAS Meeting Abstracts, 223, 236.03, 2014AAS...22323603S 2014AAS...22323603S),
and the Zwicky Transient Facility (ZTF, Bellm et al.,
2019PASP..131a8002B 2019PASP..131a8002B). We collected light curves for all sources in our
sample having spectral type later than K, except for HD 292921, that
has no published time series in the data sets we considered. We
provided the light curves for these 18 long-period variables (LPVs).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
stars.dat 83 18 List of studied LPVs
lcs.dat 78 18326 Light curves of the 18 LPVs
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
J/ApJS/249/18 : The ZTF catalog of periodic variable stars (Chen+, 2020)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Name (as in table lcs.dat)
25- 26 I2 h RAh Simbad right ascension (J2000)
28- 29 I2 min RAm Simbad right ascension (J2000)
31- 35 F5.2 s RAs Simbad right ascension (J2000)
37 A1 --- DE- Simbad declination sign (J2000)
38- 39 I2 deg DEd Simbad declination (J2000)
41- 42 I2 arcmin DEm Simbad declination (J2000)
44- 47 F4.1 arcsec DEs Simbad declination (J2000)
49- 54 F6.2 d Per Adopted period (from table3 of the paper)
56- 59 A4 --- r_Per Adopted period reference (1)
61- 83 A23 --- SName Simbad name
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Note (1): Adopted period reference as follows:
G = Gaia DR2
A = ASAS-SN
A(c) = ASAS-SN (recomputed from a time series produced by the survey rather
than taken from the corresponding variability catalog)
Z(c) = ZTF (recomputed from a time series produced by the survey rather than
taken from the corresponding variability catalog)
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Byte-by-byte Description of file: lcs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Source name
25- 42 F18.10 d JD Observation time (1)
44- 53 F10.7 mag mag ? Magnitude in Filter band
55- 66 F12.10 mag e_mag ? Magnitude uncertainty
68- 75 A8 --- Survey Name of the survey
77- 78 A2 --- Filter Name of the photometric filter (2)
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Note (1): Heliocentric Julian Date (HJD) for ASAS-SN and ZTF sources,
Baricentric Julian Date (BJD) for Gaia DR2 sources (the difference
is of a few seconds and negligible compared to LPV periods)
Note (2): Filters as follows:
G = Gaia G band
BP = Gaia BP band
RP = Gaia RP band
V = ASAS-VN V band
g = ASAS-VN g band
zg = ZTF g band
zr = ZTF r band
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Acknowledgements:
Michele Trabucchi, michele.trabucchi(at)unige.ch
(End) M. Trabucchi [Geneva Univ., Switzerland], P. Vannier [CDS] 08-Dec-2021