J/A+A/684/A205 Identification of globular cluster escaped stars (Xu+, 2024)
Where do they come from? Identification of globular cluster escaped stars.
Xu C., Tang B., Li C., Fernandez-Trincado J.G, Zhong J., Wang L., Tian H.,
Huang Y.
<Astron. Astrophys. 684, A205 (2024)>
=2024A&A...684A.205X 2024A&A...684A.205X (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Populations, stellar ; Radial velocities ;
Abundances, [Fe/H]
Keywords: stars: chemically peculiar - stars: evolution -
globular clusters: general - Galaxy: kinematics and dynamics
Abstract:
Globular clusters (GCs), as old as our Galaxy, constantly lose their
members to the field as they cross through the Milky Way (MW). These
GC escaped stars (or escapees) are suggested to contribute
significantly to the MW halo. If a star has left the host GC a long
time ago, chemical finger prints, e.g., N enrichment, may reveal its
origin. In this work, we aim to establish dynamical connections
between N-rich field stars recently identified by LAMOST and the
existing MW GCs. By constructing the full action distribution, and
combining with metallicity, we found 29 potential GC progenitors for
15 N-rich field stars. Particularly, some of them may be related to MW
accretion events. On the other hand, if a star recently left its host
GC via tidal evaporation, it still maintain the kinematic properties
of the cluster. Here we identify extra-tidal candidates based on their
spatial locations, proper motions (PMs), and their position on
color-magnitude-diagrams (CMDs). We successfully identified more than
1600 extra-tidal candidates in the vicinity of six Gaia-Enceladus
(GE)-related GCs (i.e., NGC 1851, NGC 1904, NGC 6205, NGC 6341,
NGC 6779, NGC 7089). The density map of the extra-tidal candidates is
confirmed to be an efficient way to find extra-tidal structures. The
possible two density peaks at opposite directions of the inner
boundary is a good indicator for long stellar stream. Among 95
extra-tidal candidates with spectroscopic radial velocities and
metallicity, 54 of them are confirmed to be GC escaped stars, as they
share similar properties as host GCs. These extra-tidal candidates are
ideal targets for follow-up spectroscopic observation, as it greatly
improves the scientific outcome. Once statistically significant number
of spectroscopic radial velocities and metallicities are available,
the GC dynamical evolution (e.g., mass loss, rotation) can be
carefully investigated.
Description:
In Table 4 we present the Gaia EDR3 id of identified extra-tidal stars
near 4 GCs (NGC 1851, NGC 6205, NGC 6341, NGC 7089), as well as their
radial velocity and metallicity information.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 54 54 Identified extra-tidal stars from Method IIork
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See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- GaiaEDR3 Gaia EDR3 id of this star
21- 28 A8 --- GC Globular cluster name
30- 36 F7.2 km/s RV Radial velocity
38- 42 F5.2 [-] [Fe/H] ? Metallicity
44- 54 A11 --- Source Spectra from which survey
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Acknowledgements:
Cheng Xu, xuch65(at)mail2.sysu.edu.cn
(End) Patricia Vannier [CDS] 05-Feb-2024