J/MNRAS/491/3251 Globular clusters in the inner Galaxy (Perez-Villegas+, 2020)
Globular clusters in the inner Galaxy classified from dynamical orbital
criteria.
Perez-Villegas A., Barbuy B., Kerber L.O., Ortolani S., Souza S.O., Bica E.
<Mon. Not. R. Astron. Soc., 491, 3251-3265 (2020)>
=2020MNRAS.491.3251P 2020MNRAS.491.3251P (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Milky Way ; Optical ; Stars, distances ;
Proper motions ; Radial velocities ; Abundances, [Fe/H]
Keywords: Galaxy: bulge - globular clusters: general -
Galaxy: kinematics and dynamics
Abstract:
Globular clusters (GCs) are the most ancient stellar systems in the
Milky Way. Therefore, they play a key role in the understanding of the
early chemical and dynamical evolution of our Galaxy. Around 40 per
cent of them are placed within ∼4kpc from the Galactic centre. In that
region, all Galactic components overlap, making their disentanglement
a challenging task. With Gaia Data Release 2, we have accurate
absolute proper motions for the entire sample of known GCs that have
been associated with the bulge/bar region. Combining them with
distances, from RR Lyrae when available, as well as radial velocities
from spectroscopy, we can perform an orbital analysis of the sample,
employing a steady Galactic potential with a bar. We applied a
clustering algorithm to the orbital parameters apogalactic distance
and the maximum vertical excursion from the plane, in order to
identify the clusters that have high probability to belong to the
bulge/bar, thick disc, inner halo, or outer halo component. We found
that ∼30 per cent of the clusters classified as bulge GCs based on
their location are just passing by the inner Galaxy, they appear to
belong to the inner halo or thick disc component, instead. Most GCs
that are confirmed to be bulge GCs are not following the bar structure
and are older than the epoch of the bar formation.
Description:
The sample includes 40 GCs from the list of bulge GCs by Bica et al.
(2016PASA...33...28B 2016PASA...33...28B, their table 1), for which radial velocities are
available. Another 37 GCs from the outer shell, clusters somewhat
farther, at distances 3.0<dGC<4.5kpc, some clusters with
dGC>4.5kpc from the Galactic centre (Bica et al.
2016PASA...33...28B 2016PASA...33...28B; their table 2), and the halo GC NGC 6752 are also
added, with the purpose of identifying differences in the orbital
properties among clusters that belong to each Galactic component.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 105 78 Globular clusters data
table2.dat 59 78 Globular cluster distances from the literature
table4.dat 139 78 Orbital parameters for different bar pattern
speed
table5.dat 76 78 Membership probability for different bar pattern
speed
table6.dat 23 78 Classification of GCs based on dynamical
properties, assuming their maximum membership
probability
table7.dat 25 29 Bulge GC orbits that follow the Galactic bar
for different pattern speed
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
VII/202 : Globular Clusters in the Milky Way (Harris, 1997)
J/MNRAS/482/5138 : Galactic GC mean proper motions & velocities
(Baumgardt+, 2019)
J/AJ/133/1287 : JHK photometry of 24 Galactic globular clusters
(Valenti+, 2007)
J/A+A/450/105 : Properties of 153 Galactic globular clusters (Bica+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Cluster name
12 A1 --- f_Name [*] Flag on Name (1)
14- 19 F6.2 deg RAdeg Right ascension (J2000)
21- 26 F6.2 deg DEdeg Declination (J2000)
28- 33 F6.2 deg GLON Galactic longitude
35- 40 F6.2 deg GLAT Galactic latitude
42- 46 F5.2 kpc Dist Distance
48- 51 F4.2 kpc e_Dist Error on Dist
53 A1 --- r_Dist Reference for Dist (2)
55- 61 F7.2 km/s RV Radial velocity
63- 67 F5.2 km/s e_RV Error on RV
69 A1 --- r_RV Reference for RV (2)
71- 75 F5.2 mas/yr pmRA Proper motion in right ascension
77- 80 F4.2 mas/yr e_pmRA Error on pmRA
82- 87 F6.2 mas/yr pmDE Proper motion in declination
89- 92 F4.2 mas/yr e_pmDE Error on pmDE
94- 98 F5.2 [-] [Fe/H] Fe/H abundance ratio (3)
100 A1 --- r_[Fe/H] Reference for [Fe/H] (2)
102-105 F4.2 arcmin Rc Core radius from Harris (1996AJ....112.1487H 1996AJ....112.1487H,
Cat. VII/202)
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Note (1): Flag as follows:
* = For the proper motion derivation from Gaia DR2, we selected the
individual stars within 5arcmin from the cluster centre. We removed
the stars with PM errors >0.25mas/yr. Then, stars in each cluster were
retrieved, within the core radius of each cluster from Harris
(1996AJ....112.1487H 1996AJ....112.1487H, Cat. VII/202) to estimate the PMs. A selection of
member stars was carried out with a combined plot of PMs in both
directions, and through a Gaussian mixture model (GMM), in order to get
the mean PM in each direction and their uncertainties. We applied this
method to 32 GCs of our sample.
Note (2): References as follows:
a = Ortolani et al. (2019A&A...622A..94O 2019A&A...622A..94O)
b = Ortolani et al. (2019A&A...627A.145O 2019A&A...627A.145O)
c = Kerber et al. (2019MNRAS.484.5530K 2019MNRAS.484.5530K)
d = Harris (1996AJ....112.1487H 1996AJ....112.1487H, Cat. VII/202)
e = Baumgardt et al. (2019MNRAS.482.5138B 2019MNRAS.482.5138B, Cat. J/MNRAS/482/5138)
f = Oliveira et al. (2019, in preparation)
g = Kerber et al. (2018ApJ...853...15K 2018ApJ...853...15K)
h = Barbuy et al. (2018A&A...619A.178B 2018A&A...619A.178B, Cat. J/A+A/619/A178)
i = Vasquez et al. (2018A&A...619A..13V 2018A&A...619A..13V, Cat. J/A+A/619/A13)
j = Barbuy et al. (2016A&A...591A..53B 2016A&A...591A..53B)
k = Dias et al. (2016A&A...590A...9D 2016A&A...590A...9D, Cat. J/A+A/590/A9)
l = Barbuy et al. (2014A&A...570A..76B 2014A&A...570A..76B)
m = Bica et al. (2016PASA...33...28B 2016PASA...33...28B, their table 3)
Note (3): Metallicities with no reference come from the website by Bruno Dias
(http://www.sc.eso.org/~bdias/catalogues.html)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Cluster name
12 A1 --- f_Name [*] Flag on Name (1)
14- 18 F5.2 kpc Dist Adopted distance
20- 23 F4.2 kpc e_Dist Error on Dist
25- 29 F5.2 kpc DH10 ? Distance from Harris (1996AJ....112.1487H 1996AJ....112.1487H,
Cat. VII/202)
31- 35 F5.2 kpc DB19 Distance from Baumgardt et al.
(2019MNRAS.482.5138B 2019MNRAS.482.5138B, Cat. J/MNRAS/482/5138)
37- 41 F5.2 kpc DV07 ? Distance from Valenti, Ferraro & Origlia
(2007AJ....133.1287V 2007AJ....133.1287V, Cat. J/AJ/133/1287)
43- 47 F5.2 kpc DGaia ? Distance from estimated by the inverse of
the parallax from Gaia DR2
(2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345)
49- 53 F5.2 kpc Dours ? Distance taken from isochrone fittings of
the CMD and RR Lyrae estimated by our group
55- 59 F5.2 kpc DB06 ? Distance from Bica et al.
(2006A&A...450..105B 2006A&A...450..105B, Cat. J/A+A/450/105)
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Note (1): Flag as follows:
* = GCs with the largest difference in distance determinations in the
literature
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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- 10 A10 --- Name Cluster name
12- 15 F4.2 kpc rp40 Median perigalactic distance for
Ωb=40km/s/kpc
17- 20 F4.2 kpc e_rp40 Error on rp40
22- 26 F5.2 kpc ra40 Median apogalactic distance for
Ωb=40km/s/kpc
28- 32 F5.2 kpc e_ra40 Error on ra40
34- 38 F5.2 kpc z40 Maximum vertical excursion from the Galactic
plane for Ωb=40km/s/kpc
40- 43 F4.2 kpc e_z40 Error on z40
45- 48 F4.2 --- e40 Orbital eccentricity for Ωb=40km/s/kpc
50- 53 F4.2 --- e_e40 Error on e40
55- 58 F4.2 kpc rp45 Median perigalactic distance for
Ωb=45km/s/kpc
60- 63 F4.2 kpc e_rp45 Error on rp45
65- 69 F5.2 kpc ra45 Median apogalactic distance for
Ωb=45km/s/kpc
71- 75 F5.2 kpc e_ra45 Error on ra45
77- 81 F5.2 kpc z45 Maximum vertical excursion from the Galactic
plane for Ωb=45km/s/kpc
83- 86 F4.2 kpc e_z45 Error on z45
88- 91 F4.2 --- e45 Orbital eccentricity for Ωb=45km/s/kpc
93- 96 F4.2 --- e_e45 Error on e45
98-101 F4.2 kpc rp50 Median perigalactic distance for
Ωb=50km/s/kpc
103-106 F4.2 kpc e_rp50 Error on rp50
108-112 F5.2 kpc ra50 Median apogalactic distance for
Ωb=50km/s/kpc
114-118 F5.2 kpc e_ra50 Error on ra50
120-124 F5.2 kpc z50 Maximum vertical excursion from the Galactic
plane for Ωb=50km/s/kpc
126-129 F4.2 kpc e_z50 Error on z50
131-134 F4.2 --- e50 Orbital eccentricity for Ωb=50km/s/kpc
136-139 F4.2 --- e_e50 Error on e50
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Cluster name
12- 15 F4.1 % Bulge40 Probability of the cluster to be part of the
bulge for Ωb=40km/s/kpc
17- 21 F5.1 % Disk40 Probability of the cluster to be part of the
disk for Ωb=40km/s/kpc
23- 26 F4.1 % Haloi40 Probability of the cluster to be part of the
inner halo for Ωb=40km/s/kpc
28- 32 F5.1 % Haloo40 Probability of the cluster to be part of the
outer halo for Ωb=40km/s/kpc
34- 37 F4.1 % Bulge45 Probability of the cluster to be part of the
bulge for Ωb=45km/s/kpc
39- 43 F5.1 % Disk45 Probability of the cluster to be part of the
disk for Ωb=45km/s/kpc
45- 48 F4.1 % Haloi45 Probability of the cluster to be part of the
inner halo for Ωb=45km/s/kpc
50- 54 F5.1 % Haloo45 Probability of the cluster to be part of the
outer halo for Ωb=45km/s/kpc
56- 59 F4.1 % Bulge50 Probability of the cluster to be part of the
bulge for Ωb=50km/s/kpc
61- 65 F5.1 % Disk50 Probability of the cluster to be part of the
disk for Ωb=50km/s/kpc
67- 70 F4.1 % Haloi50 Probability of the cluster to be part of the
inner halo for Ωb=50km/s/kpc
72- 76 F5.1 % Haloo50 Probability of the cluster to be part of the
outer halo for Ωb=50km/s/kpc
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Cluster name
12 A1 --- f_Name [*] Flag on Name (1)
14- 23 A10 --- Comp Component (Bulge/Bar, Thick disc, Inner halo
or Outer halo)
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Note (1): Flag as follows:
* = Globular cluster for which its classification changes with Ωb
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Cluster name
12- 15 F4.1 % Orbbar40 Percentage of orbits in the bulge GC that
support the bar shape for
Ωb=40km/s/kpc
17- 20 F4.1 % Orbbar45 Percentage of orbits in the bulge GC that
support the bar shape for
Ωb=45km/s/kpc
22- 25 F4.1 % Orbbar50 Percentage of orbits in the bulge GC that
support the bar shape for
Ωb=50km/s/kpc
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 17-Feb-2023