J/ApJ/889/99 Gaia DR2 Blanco 1 member candidates (Zhang+, 2020)
Diagnosing the stellar population and tidal structure of the Blanco 1 star
cluster.
Zhang Y., Tang S.-Y., Chen W.P., Pang X., Liu J.Z.
<Astrophys. J. 889, 99 (2020)>
=2020ApJ...889...99Z 2020ApJ...889...99Z (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Populations, stellar ;
Parallaxes, trigonometric ; Proper motions ; Radial velocities
Keywords: stars: evolution - stars: mass function -
open clusters and associations: individual (Blanco 1)
Abstract:
We present the stellar population, using Gaia DR2 parallax,
kinematics, and photometry, of the young (∼100Myr), nearby (∼230pc)
open cluster, Blanco 1. A total of 644 member candidates are
identified via the unsupervised machine learning method StarGO to find
the clustering in the 5-dimensional position and proper motion
parameter (X, Y, Z, µα*cosδ, µδ) space. Within
the tidal radius of 10.0±0.3pc, there are 488 member candidates, 3
times more than those outside. A leading tail and a trailing tail,
each of 50-60pc in the Galactic plane, are found for the first time
for this cluster, with stars further from the cluster center streaming
away faster, manifest stellar stripping. Blanco 1 has a total detected
mass of 285±32M☉ with a mass function consistent with a slope
of alpha=1.35±0.2 in the sense of dN/dm∝m-alpha, in the
mass range of 0.25-2.51M☉, where N is the number of members and
$m$ is stellar mass. A Minimum Spanning Tree ({LAMBDA}MSR) analysis
shows the cluster to be moderately mass segregated among the most
massive members (≳1.4M☉), suggesting an early stage of
dynamical disintegration.
Description:
In this work, using Gaia/DR2 data, we present detailed
characterization of the Blanco 1 star cluster, by identification of
its members, with which the cluster parameters, including tidal
structures, are derived.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 76 644 Gaia DR2 Blanco 1 member candidates
--------------------------------------------------------------------------------
See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/601/A19 : Gaia DR1 open cluster members (Gaia Collaboration+, 2017)
J/MNRAS/413/1024 : Deep proper-motion survey of Blanco 1 (Platais+, 2011)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq Internal index number (1)
5- 14 F10.6 deg RAdeg Right Ascension (ICRS) at Ep=J2015.5
16- 25 F10.6 deg DEdeg Declination (ICRS) at Ep=J2015.5
27- 30 F4.2 mas plx Parallax
32- 35 F4.2 mas e_plx Uncertainty in plx
37- 41 F5.2 mas/yr pmRA* Proper motion in RA*cos(DE)
43- 46 F4.2 mas/yr e_pmRA* Uncertainty in pmRA*
48- 51 F4.2 mas/yr pmDE Proper motion in DE
53- 56 F4.2 mas/yr e_pmDE Uncertainty in pmDE
58- 62 F5.2 km/s RV ? Radial velocity
64- 68 F5.2 km/s e_RV ? Uncertainty in RV
70- 74 F5.2 mag Gmag Apparent Gaia broad G band magnitude
76 A1 --- f_Seq [bt] Flag on Seq (2)
--------------------------------------------------------------------------------
Note (1): Sorted according to RA.
Note (2): Flag as follows:
b = A "bound" member candidate within the tidal radius
t = A member candidate in the "tail" (see Section 3.3)
--------------------------------------------------------------------------------
Acknowledgements:
Shih-Yun Tang, sytang(at)g.ncu.edu.tw
(End) Patricia Vannier [CDS] 21-Feb-2020