J/A+A/665/A8 Extra-tidal star candidates in Sgr dSph Galaxy (Kundu+, 2022)
Extra-tidal star candidates in globular clusters of the Sagittarius
dwarf spheroidal galaxy.
Kundu R., Navarrete C., Sbordone L., Carballo-Bello J.A.,
Fernandez-Trincado J.G., Minniti D., Singh H.P.
<Astron. Astrophys. 665, A8 (2022)>
=2022A&A...665A...8K 2022A&A...665A...8K (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Proper motions ; Magnitudes ; Optical
Keywords: globular clusters: general -
galaxies: clusters: individual: Sgr dSph - galaxies: dwarf -
Galaxy: formation - Galaxy: stellar content
Abstract:
Globular clusters (GCs) associated with the Sagittarius dwarf
spheroidal galaxy (Sgr dSph) have evolved under the gravitational
potential of both Sgr dSph and the Milky Way. The effects of these
potentials are most pronounced in the extra-tidal regions as compared
to the central regions of the GCs.We aim to study the extra-tidal
regions of the GCs that are possibly associated with Sgr dSph, namely
Arp 2, Terzan 8, NGC 5634, NGC 6284, Terzan 7, NGC 2419, NGC 4147,
M 54 and Pal 12, using data from the Gaia early data release 3.
We selected the extra-tidal candidates based on their angular
distances from the cluster centre in the RA-Dec plane, proper motions
of the clusters and the individual extra-tidal star candidates, and
their positions on the colour-magnitude diagrams of the clusters. We
found extra-tidal candidates for the nine studied GCs. For eight of
them, the surface density of candidate extra-tidal stars in the
vicinity of the clusters is in significant excess with respect to more
distant surrounding fields. No extended extra-tidal features beyond 5
tidal radii were detected for any of the clusters. We publish a list
of the most probable extra-tidal candidates that we determined using
Gaia astrometric and photometric data. Our analysis shows that
the clusters that are associated with Sgr dSph are more likely
affected by the gravitational potential of the Sgr, as the
distribution of extra-tidal stars is elongated in the same direction
as the local stream. NGC 4147 is the only exception. We found some
high-probability candidate extra-tidal stars in several of the
analysed clusters. We failed to detect any coherent large-scale tidal
tail around them.
Description:
In the tables we provide list of extra-tidal stars corresponding each
cluster analysed in our study. The name of the tables indicate the
corresponding clusters.
Objects:
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RA (ICRS) DE Designation(s)
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19 28 44.11 -30 21 20.3 Arp2 = Cl Arp 2
18 55 03.33 -30 28 47.5 M54 = M 54
07 38 08.51 +38 52 54.9 NGC2419 = NGC 2419
12 10 06.15 +18 32 31.8 NGC4147 = NGC 4147
14 29 37.28 -05 58 35.1 NGC5634 = NGC 5634
17 04 28.75 -24 45 51.2 NGC6284 = NGC 6284
21 46 38.84 -21 15 09.4 Pal12 = Cl Pal 12
19 17 43.92 -34 39 27.8 Terzan7 = Cl Terzan 7
19 41 44.41 -33 59 58.1 Terzan8 = Cl Terzan 8
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
arp2.dat 106 315 Extra-tidal stars belonging to Arp 2
m54.dat 106 233 Extra-tidal stars belonging to M 54
ngc2419.dat 105 38 Extra-tidal stars belonging to NGC 2419
ngc4147.dat 106 11 Extra-tidal stars belonging to NGC 4147
ngc5634.dat 106 15 Extra-tidal stars belonging to NGC 5634
ngc6284.dat 106 248 Extra-tidal stars belonging to NGC 6284
pal12.dat 106 77 Extra-tidal stars belonging to Pal 12
terzan7.dat 106 491 Extra-tidal stars belonging to Terzan 7
terzan8.dat 106 110 Extra-tidal stars belonging to Terzan 8
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See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
Byte-by-byte Description of file: *.dat
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Bytes Format Units Label Explanations
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1- 11 F11.7 deg RAdeg Right ascension (ICRS) at Ep=2016.0
13- 22 F10.6 deg DEdeg Declination (ICRS) at Ep=2016.0
24- 31 F8.5 mas/yr pmRA Proper motion along RA, pmRA*cosDE
33- 39 F7.5 mas/yr e_pmRA rms uncertainty on proper motion along RA
41- 48 F8.5 mas/yr pmDE Proper motion along DE
50- 56 F7.5 mas/yr e_pmDE rms uncertainty on proper motion along DE
58- 66 F9.6 mag Gmag Gaia G magnitude
68- 76 F9.6 mag BPmag Gaia BP magnitude
78- 86 F9.6 mag RPmag Gaia RP magnitude
88-106 I19 --- GaiaEDR3 Gaia EDR3 source_id
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Acknowledgements:
Richa Kundu, richakundu92(at)gmail.com
(End) Patricia Vannier [CDS] 11-Jun-2022