J/A+A/684/A173 RR Lyrae stars in Galactic Globular Clusters (Cruz Reyes+, 2024)
Variable stars in Galactic globular clusters.
I. The population of RR Lyrae stars.
Cruz Reyes M., Anderson R.I., Johansson L., Netzel H., Medaric Z.
<Astron. Astrophys. 684, A173 (2024)>
=2024A&A...684A.173C 2024A&A...684A.173C (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, globular ; Stars, variable ; Optical
Keywords: catalogs - stars: variables: RR Lyrae - globular clusters: general
Abstract:
We present a comprehensive catalog of 2824 RR Lyrae stars (RRLs)
residing in 115 Galactic globular clusters (GCs). Our catalog includes
1594 fundamental- mode (RRab), 824 first-overtone (RRc), and 28
double-mode (RRd) RRLs, as well as 378 RRLs of an unknown pulsation
mode. We cross-matched 481349 RRLs reported in the third data release
(DR3) of the ESA mission Gaia and the literature to 170 known GCs.
Membership probabilities were computed as the products of a position
and shape-dependent prior and a likelihood was computed using
parallaxes, proper motions, and, where available, radial velocities
from Gaia. Membership likelihoods of RRLs were computed by comparing
cluster average parameters based on known member stars and the
cross-matched RRLs. We determined empirical RRL instability strip (IS)
boundaries based on our catalog and detected three new cluster RRLs
inside this region via their excess Gaia G-band photometric
uncertainties. We find that 77% of RRLs in GCs are included in the
Gaia DR3 Specific Object Study, and 82% were classified as RRLs by the
Gaia DR3 classifier, with the majority of the missing sources being
located at the crowded GC centers. Surprisingly, we find that 25% of
cluster member stars located within the empirical IS are not RRLs and
appear to be non-variable. Additionally, we find that 80% of RRab, 84%
of RRc, and 100% of the RRd stars are located within theoretical IS
boundaries predicted using MESA models with Z=0.0003, M=0.7M☉,
and Y=0.290. Unexpectedly, a higher Y=0.357 is required to fully match
the location of RRc stars, and lower Y=0.220 is needed to match the
location of RRab stars. Lastly, our catalog does not exhibit an
Oosterhoff dichotomy, with at least 22 GCs located inside the
Oosterhoff 'gap,' which is close to the mode of the distribution of
mean RRL periods in GCs.
Description:
Using the astrometry of the Gaia early data release 3 (Gaia
Collaboration et al., 2021A&A...649A...1G 2021A&A...649A...1G, Cat. I/350), Vasiliev &
Baumgardt (2021MNRAS.505.5978V 2021MNRAS.505.5978V, Cat. J/MNRAS/505/5978) identified the
cluster member stars of 170 Milky Way GCs. Our analysis relies on the
clusters and the associated members identified by them.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 140 4764 Results of the membership analysis of
RR Lyrae stars in clusters
table4.dat 41 315 Non variable stars located in the instability
strip for RR Lyrae stars
tablea2.dat 328 170 Globular cluster parameters
tabled1.dat 55 63 Sources in the Specific Object Study for RRLs
with unrealistic photometric uncertainties
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
V/150 : Updated catalog of variable stars in globular clusters (Clement+ 2017)
J/MNRAS/505/5978 : Gaia EDR3 view on Galactic globular clusters
(Vasiliev+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Gaia DR3 source id
21- 35 A15 --- Cluster Cluster in which the star is located
37- 55 F19.16 --- likelihood [0/1]? Likelihood
57- 75 F19.16 --- prior [0/1]? Prior probability
77- 98 E22.17 --- posterior [0/1]? Posterior probability
100-104 A5 --- RVflag Boolean column. When set to True, it indicates
that the SOS radial velocity was used to
compute the likelihood
106-110 A5 --- SOS Boolean column. When set to True, it indicates
that the star was detected as an RR Lyrae
by SOS analysis
112-116 A5 --- classifier Boolean column. When set to True, it indicates
that the star was detected as an RR Lyrae
by the classifier
118-122 A5 --- G23 Boolean column that specifies whether an
RR Lyrae is included in the Gaia Coll. et
al., (2023A&A...674A...1G 2023A&A...674A...1G, Cat. I/355)
catalog
124-128 A5 --- C17 Boolean column that specifies whether an
RR Lyrae is included in the Clement
2017EPJWC.15201021C 2017EPJWC.15201021C) catalog
130-134 A5 --- New Boolean column that specifies whether an
RR Lyrae was detected with the method
presented in Section 3.6 of the paper
136-140 A5 --- Final Boolean column that specifies whether an
RR Lyrae is in our final sample of RR Lyrae
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Gaia DR3 source id
21- 33 A13 --- Cluster Cluster in which the star is located
35- 41 F7.5 --- Pmember Membership probability determined by VB21
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Cluster Cluster name
17- 21 I5 --- Nstars Number of stars used for the determination
of the astrometric parameters
23- 41 F19.16 mas plx ? Cluster parallax including the Lindegren
et al. (2021A&A...649A...4L 2021A&A...649A...4L) offset
correction
43- 61 F19.16 mas e_plx ? Cluster parallax uncertainty, including
the angular covariance
63- 82 F20.16 mas/yr pmRA ? Mean cluster proper motion in right
ascension
84-102 F19.16 mas/yr e_pmRA ? Standard error on the mean proper motion
in right ascension
104-123 F20.16 mas/yr pmDE ? Mean cluster proper motion in declination
125-143 F19.16 mas/yr e_pmDE ? Standard error on the proper motion in
declination
145-164 F20.15 km/s RV ? Median radial velocity
166-185 F20.16 km/s e_RV ? Uncertainty on the median radial velocity
187-189 I3 --- o_RV Number of stars used to determined the
radial velocity
191-195 F5.2 --- E(B-V) ? Reddening (1)
197-202 I6 --- NstarsPCA Number of stars used for the determination
of the PCA parameters
204-223 F20.15 deg PA ? Position angle determined with the PCA
225-244 F20.16 deg e_PA ? Uncertainty in the position angle
246-264 F19.16 --- ac ? Core ellipse
266-284 F19.16 --- alim ? Limiting ellipse
286-304 F19.16 --- ell ? Cluster ellipticity
306-324 F19.16 --- e_ell ? Uncertainty in the cluster ellipticity
326-328 I3 --- NRRLyr ? Number of detected RR Lyrae in the
cluster
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Note (1): from the catalog of cluster parameters of Harris
(2010arXiv1012.3224H 2010arXiv1012.3224H). For FSR 1758 we used the value provided by
Romero Colmenares et al. (2021A&A...652A.158R 2021A&A...652A.158R)
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Byte-by-byte Description of file: tabled1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Gaia DR3 source id
21- 34 E14.9 mag e_BPmag Uncertainty on the intensity-averaged
magnitude in the BP band (intaveragebp)
36- 37 I2 --- o_BPmag Number of BP epochs used to determine
intaveragebp
39- 52 E14.9 mag e_RPmag Uncertainty on the intensity-averaged
magnitude in the RP band (intaveragerp)
54- 55 I2 --- o_RPmag Number of RP epochs used to determine
intaveragerp
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Acknowledgements:
Mauricio Cruz Reyes, mauricio.cruz(at)correo.nucleares.unam.mx
(End) Patricia Vannier [CDS] 15-Feb-2024