J/ApJ/923/20 Hierarchical clustering in Vela OB2 complex (Pang+, 2021)
Disruption of hierarchical clustering in the Vela OB2 complex and the cluster
pair Collinder 135 and UBC 7 with Gaia EDR3: evidence of supernova quenching.
Pang X., Yu Z., Tang S.-Y., Hong J., Yuan Z., Pasquato M.,
Kouwenhoven M.B.N.
<Astrophys. J., 923, 20 (2021)>
=2021ApJ...923...20P 2021ApJ...923...20P
ADC_Keywords: Clusters, open; Proper motions; Velocity dispersion;
Radial velocities; Photometry; Optical; Stars, distances
Keywords: Star clusters ; Open star clusters ; Stellar kinematics
Abstract:
We identify hierarchical structures in the Vela OB2 complex and the
cluster pair Collinder 135 and UBC 7 with Gaia EDR3 using the neural
network machine-learning algorithm StarGO. Five second-level
substructures are disentangled in Vela OB2, which are referred to as
Huluwa 1 (Gamma Velorum), Huluwa 2, Huluwa 3, Huluwa 4, and Huluwa 5.
For the first time, Collinder 135 and UBC 7 are simultaneously
identified as constituent clusters of the pair with minimal manual
intervention. We propose an alternative scenario in which Huluwa 1-5
have originated from sequential star formation. The older clusters
Huluwa 1-3, with an age of 10-22Myr, generated stellar feedback to
cause turbulence that fostered the formation of the younger-generation
Huluwa 4-5 (7-20Myr). A supernova explosion located inside the Vela
IRAS shell quenched star formation in Huluwa 4-5 and rapidly expelled
the remaining gas from the clusters. This resulted in global mass
stratification across the shell, which is confirmed by the regression
discontinuity method. The stellar mass in the lower rim of the shell
is 0.32±0.14M☉ higher than in the upper rim. Local, cluster-
scale mass segregation is observed in the lowest-mass cluster Huluwa
5. Huluwa 1-5 (in Vela OB2) are experiencing significant expansion,
while the cluster pair suffers from moderate expansion. The velocity
dispersions suggest that all five groups (including Huluwa 1A and
Huluwa 1B) in Vela OB2 and the cluster pair are supervirial and are
undergoing disruption, and also that Huluwa 1A and Huluwa 1B may be a
coeval young cluster pair. N-body simulations predict that Huluwa 1-5
in Vela OB2 and the cluster pair will continue to expand in the future
100Myr and eventually dissolve.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 124 9 General parameters of target clusters
table2.dat 241 3787 Individual members of the five clusters in Vela OB2,
and the cluster pair Collinder 135 and UBC 7
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See also:
B/ocl : Optically visible open clusters and Candidates (Dias+ 2002-2015)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/117/354 : OB associations from Hipparcos (de Zeeuw+, 1999)
J/A+A/391/547 : Binary and multiple clusters in the LMC (Dieball+, 2002)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/ApJS/186/191 : VI photometry & spectroscopy in h+χ Per (Currie+, 2010)
J/ApJ/764/73 : HST VI phot. of HD 97950 cluster members stars (Pang+, 2013)
J/A+A/563/A94 : Kinematics of the Gamma Vel cluster (Jeffries+, 2014)
J/A+A/574/L7 : Gaia-ESO Survey: Li-rich stars in NGC2547 (Sacco+, 2015)
J/A+A/586/A41 : LMC star clusters catalog (Palma+, 2016)
J/A+A/589/A70 : Gamma Vel cluster membership and IMF (Prisinzano+, 2016)
J/A+A/599/A49 : PMS stars evolutionary models (Kunitomo+, 2017)
J/MNRAS/472/3887 : Kinematic data for stars in OB-associations (Melnik+, 2017)
J/A+A/618/A93 : Gaia DR2 open clusters in the MW (Cantat-Gaudin+, 2018)
J/A+A/618/A59 : Gaia DR2 new nearby open clusters (Castro-Ginard+, 2018)
J/AJ/156/84 : APOGEE-2 survey of Orion Complex. II. (Kounkel+, 2018)
J/A+A/626/A17 : Young pop. in Vela-Puppis region (Cantat-Gaudin+, 2019)
J/A+A/621/A115 : Vela OB2 members (Cantat-Gaudin+, 2019)
J/A+A/627/A119 : Extended halo of NGC 2682 (M 67) (Carrera+ 2019)
J/A+A/631/A166 : Members of 5 cluster in Ori OB1a association (Kos+, 2019)
J/ApJS/245/32 : Newly identified star clusters in Gaia DR2 (Liu+, 2019)
J/ApJ/877/12 : Coma Ber & Neighbor Stellar Group tidal tails (Tang+, 2019)
J/A+A/640/A1 : Portrait Galactic disc (Cantat-Gaudin+, 2020)
J/ApJ/891/39 : LAMOST DR3 VMP stars of the Galactic halo (Yuan+, 2020)
J/ApJ/917/23 : SPYGLASS. I. Mapping young stellar structures (Kerr+, 2021)
J/ApJ/912/162 : Open clusters in solar neighborhood (Pang+, 2021)
J/ApJ/917/21 : Kinematics in Orion Complex with Gaia (Swiggum+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Cluster Cluster name
15 A1 --- m_Cluster Components of Huluwa 1
17- 25 A9 Myr Age Age range
27- 32 F6.1 pc Xc [-105.8/-44.2] Median X position of members
in the cluster (1)
34- 39 F6.1 pc Yc [-391.2/-252.6] Median Y position of members
in the cluster (1)
41- 45 F5.1 pc Zc [-70.1/12.8] Median Z position of members in
the cluster (1)
47- 50 F4.1 pc rh [4.7/15.3] Half-mass radius of the cluster
52- 55 F4.1 pc rt [5.7/13.1] Tidal radius of the cluster (2)
57- 61 F5.1 Msun Mcl [61/724] Total mass of the star cluster
63- 68 F6.2 mas/yr pmRA [-10.1/-4.7] Mean proper motion in RA
70- 74 F5.2 mas/yr pmDE [6/11] Mean proper motion in DEC
76- 79 F4.2 mas/yr sigpmRA [0.46/0.9] Dispersion of pmRA
81- 84 F4.2 mas/yr e_sigpmRA [0.03/0.2] Negative uncertainty on sigpmRA
86- 89 F4.2 mas/yr E_sigpmRA [0.03/0.4] Positive uncertainty on sigpmRA
91- 94 F4.2 mas/yr sigpmDE [0.3/1.1] Dispersion of pmDE
96- 99 F4.2 mas/yr e_sigpmDE [0.03/0.2] Negative uncertainty on sigpmDE
101- 104 F4.2 mas/yr E_sigpmDE [0.03/0.3] Positive uncertainty on sigpmDE
106- 109 F4.2 km/s sigma [0.35/2.4]? RV dispersion after correction,
σRV (3)
111- 114 F4.2 km/s e_sigma [0.2/0.92]? Negative uncertainty on sigma
116- 119 F4.2 km/s E_sigma [0.16/1.2]? Positive uncertainty on sigma
121- 124 I4 --- Mm [102/1294] Number of members
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Note (1): Xc , Yc , and Zc are the median positions of members in each cluster,
in heliocentric Cartesian coordinates after distance correction
(Section 5.1).
Note (2): The tidal radius is computed using Equation (12) in
Pinfield+ (1998MNRAS.299..955P 1998MNRAS.299..955P).
Note (3): Parameter σRV is the RV dispersion after correction of binary
stars and field star contamination. The latter is not available for
Huluwa 4 and 5 owing to the small number of RV measurements. Errors in
the velocity dispersion are obtained using the MCMC method.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Cluster Name of the target cluster
15 A1 --- m_Cluster Components of Huluwa 1
17- 35 I19 --- Gaia Object ID in Gaia EDR3
37- 51 F15.11 deg RAdeg [97/133.3] Gaia EDR3 Barycentric right
ascension (ICRS) at Ep=2016.0
53- 58 F6.4 mas e_RAdeg [0.006/0.21] Uncertainty in RAdeg
60- 74 F15.11 deg DEdeg [-53.2/-33] Gaia EDR3 Barycentric declination
(ICRS) at Ep=2016.0
76- 81 F6.4 mas e_DEdeg [0.007/0.3] Uncertainty in DEdeg
83- 88 F6.4 mas Plx [2.29/4] Parallax from Gaia EDR3
90- 95 F6.4 mas e_Plx [0.0081/0.2462] Uncertainty in Plx
97-103 F7.3 mas/yr pmRA [-12/-3.4] Gaia EDR3 proper motion in RA
105-109 F5.3 mas/yr e_pmRA [0.008/0.3] Uncertainty in pmRA
111-116 F6.3 mas/yr pmDE [4.8/11.5] Gaia EDR3 proper motion in DE
118-122 F5.3 mas/yr e_pmDE [0.009/0.4] Uncertainty in pmDE
124-132 F9.6 mag Gmag [4.9/19.5] Magnitude in G band from Gaia EDR3
134-142 F9.6 mag BPmag [4.8/21.7] Magnitude in BP band from Gaia EDR3
144-152 F9.6 mag RPmag [5/18.1] Magnitude in RP band from Gaia EDR3
154-161 F8.2 km/s RVel1 [-6.4/45.6]?=-9999 Gaia EDR3 Radial Velocity
163-170 F8.2 km/s e_RVel1 [0.3/20]?=-9999 Uncertianty in RVel1
172-179 F8.2 km/s RVel2 [-0.16/38]?=-9999
Jeffries+ 2014, J/A+A/563/A94 Gaia/ESO survey
radial velocity
181-188 F8.2 km/s e_RVel2 [0.13/4]?=-9999 Uncertainty in RVel2
190-193 F4.1 Msun Mass [0.1/11] Stellar mass obtained in this study
195-200 F6.1 pc Xobs [-130/-9] Heliocentric Cartesian X
coordinate (1)
202-207 F6.1 pc Yobs [-430/-229] Heliocentric Cartesian Y
coordinate (1)
209-214 F6.1 pc Zobs [-103/23.4] Heliocentric Cartesian Z
coordinate (1)
216-221 F6.1 pc Xcor [-125/-9] Heliocentric Cartesian X coordinate,
corrected (2)
223-228 F6.1 pc Ycor [-423/-236] Heliocentric Cartesian Y
coordinate, corrected (2)
230-235 F6.1 pc Zcor [-101/24] Heliocentric Cartesian Z coordinate,
corrected (2)
237-241 F5.1 pc Distcor [256/435] Corrected distance of individual
member
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Note (1): Computed via direct inverting Gaia EDR3 parallax.
Note (2): After distance correction in this study.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 04-Apr-2023