J/A+A/679/A105 Members and fugitives of nearby open clusters (Vaher+, 2023)
Finding the dispersing siblings of young open clusters.
Dynamical traceback simulations using Gaia DR3.
Vaher E., Hobbs D., McMillan P., Prusti T.
<Astron. Astrophys. 679, A105 (2023)>
=2023A&A...679A.105V 2023A&A...679A.105V (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Optical
Keywords: Galaxy: kinematics and dynamics - solar neighborhood -
open clusters and associations: general -
stars: kinematics and dynamics - stars: formation
Abstract:
Stars tend to form in clusters, but many escape their birth clusters
very early. Identifying the escaped members of clusters can inform us
about the dissolution of star clusters, but also about the stellar
dynamics in the galaxy. Methods capable of finding escaped stars from
many clusters are required to fully exploit the large amounts of data
in the Gaia era.
We present a new method of identifying escaped members of nearby
clusters and apply it to ten young clusters.
We assumed the escaped stars were close to the cluster in the past and
performed traceback computations based on the Gaia DR3 radial velocity
subsample. For each individual star, our method produces a probability
estimate that it is an escaped member of a cluster, and for each
cluster it also estimates the field star contamination rate of the
identified fugitives.
Our method is capable of finding fugitives that have escaped from
their cluster in the last few ten million years. In many cases the
fugitives form an elongated structure that covers a large volume.
The results presented here show that traceback computations using Gaia
DR3 data can identify stars that have recently escaped their cluster.
Our method will be even more useful when applied to future Gaia data
releases that contain more radial velocity measurements.
Description:
We present a list of stars that are currently or have been recently
close (in phase space) to any of a selection of ten nearby young open
clusters. Most stars either have similar membership and fugitive
probabilities, meaning they are currently in or very close to the
cluster neighborhood in phase space, or they have very low membership
probabilities, meaning their connection with the cluster is not
obvious and was revealed by traceback computations. Particularly
interesting are the stars with high fugitive probabilities but very
low membership probabilities.
The data includes all stars with positive fugitive probabilities, not
just the ones with pfug>0.1. Cluster neighborhood radius was 15pc
in position space and 5km/s in velocity space.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 94 3694 All stars with positive fugitive probabilities
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See also:
I/355 : Gaia DR3 (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 I19 --- GaiaDR3 Gaia DR3 source id
21- 41 F21.17 deg RAdeg Gaia DR3 right ascension (ICRS) at Ep=2016.0
43- 63 F21.17 deg DEdeg Gaia DR3 declination (ICRS) at Ep=2016.0
65- 68 F4.2 --- pmemb Membership probability
70- 73 F4.2 --- pfug Fugitive probability
75- 94 A20 --- Cluster Name of the cluster the star is
associated with (1)
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Note (1): Clusters are Blanco 1, IC 2391, IC 2602, Messier 39, NGC 2451 A,
NGC 2516, NGC 2547, Platais 9, Pleiades, and alpha Persei cluster.
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Acknowledgements:
Eero Vaher, eero.vaher(at)fysik.lu.se
(End) Patricia Vannier [CDS] 02-Oct-2023