J/MNRAS/533/1782 Stars assoc. and open clusters subgroups (Gregorio-Hetem+ 2024)
Structural properties of subgroups of stars associated with open clusters.
Gregorio-Hetem J., Hetem A.
<Mon. Not. R. Astron. Soc., 533, 1782-1799 (2024)>
=2024MNRAS.533.1782G 2024MNRAS.533.1782G (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; Stars, masses
Keywords: stars: pre-main-sequence - ISM: clouds -
open clusters and associations: general
Abstract:
Recent studies have identified star clusters with multiple components
based on accurate spatial distributions and/or proper motions from
Gaia Data Release 3 (DR3), utilizing diverse diagnostics to gain an
understanding of subgroup evolution. These findings motivated us to
search for subgroups among the objects examined in our previous work,
which employed fractal statistics. The present study considers seven
open clusters that exhibit significant dispersion in age and/or proper
motion distributions, suggesting that they are not single clusters. In
order to characterize the stellar groups, we calculate the membership
probability using Bayesian multidimensional analysis by fitting the
observed proper motion distribution of the candidates. A probability
distribution is also used to determine the distance of the cluster,
which is obtained from the mean value of the distance modes. The
photometry from Gaia DR3 is compared with evolutionary models to
estimate the cluster age and total mass. In our sample, double
components are found only for Markarian 38 and NGC 2659. The other
five clusters are confirmed as being single. The structural
parameters, such as Q, LambdaMSR, and SigmaLDR, are compared with
results from N-body simulations to investigate how the morphology of
the stellar clustering evolves. The new results, for a more complete
sample of cluster members, provide a better definition of the
distribution type (central concentration or substructured region)
inferred from the m-s plot.
Description:
Table 2 presents the estimated parameters for the P50 members.
Table 3 includes the mass function and the radial density profile.
Table 4 contains the results for surface density, crossing time,
dynamical age, and fractal statistics. The remaining tables, named
after the individual clusters, provide both the Gaia DR3 data and the
calculated values derived in this study.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 120 9 Parameters estimated for the P50 members
(probability over 50 percent)
table3.dat 48 9 Mass function and the radial density profile
table4.dat 106 9 Results from surface density, crossing time,
dynamical age, and fractal statistics
col205.dat 144 83 Data for the member sources found in Col205
ic2602.dat 144 295 Data for the member sources found in IC2602
mrk38a.dat 144 271 Data for the member sources found in Mrk38a
mrk38b.dat 144 75 Data for the member sources found in Mrk38b
ngc2168.dat 144 845 Data for the member sources found in NGC2168
ngc2659a.dat 144 98 Data for the member sources found in NGC2659a
ngc2659b.dat 144 96 Data for the member sources found in NGC2659b
ngc3532.dat 144 1262 Data for the member sources found in NGC3532
ngc6494.dat 144 424 Data for the member sources found in NGC6494
--------------------------------------------------------------------------------
See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Cluster Cluster name
10- 16 F7.3 deg RAdeg Mean right ascension of P50 members
(ICRS) at Ep=2016
18- 22 F5.3 deg e_RAdeg Standard deviation in right ascension
24- 30 F7.3 deg DEdeg Mean declination of P50 members
(ICRS) at Ep=2016
32- 36 F5.3 deg e_DEdeg Standard deviation in declination
38- 43 F6.2 mas/yr pmRA Proper motion along RA, pmRA*cos(DE)
45- 48 F4.2 mas/yr e_pmRA Standard deviation in pmRA
50- 55 F6.2 mas/yr pmDE Proper motion along DE
57- 60 F4.2 mas/yr e_pmDE Standard deviation in DEC
62- 65 I4 pc Dist Distance obtained from the mean values of
the modes
67- 69 I3 pc e_Dist Uncertainty in Dist
71- 74 I4 --- NP50 Number of P50 members identified on
the basis of proper motion
76- 80 F5.2 pc RP50 Cluster radius determined from the
distribution of P50 members
82- 85 F4.2 pc e_RP50 Uncertainty in RP50
87- 90 I4 MSun MP50 Mass of P50 members
92- 94 I3 Myr Age Age
96- 99 F4.2 mag E(B-V) Reddening
101-103 F3.1 mag AVmin Minimum visual extinction
105-107 F3.1 mag AVmax Maximum visual extinction
109-120 A12 --- Table Table name with members data
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Cluster Cluster name
10- 13 I4 --- Nobs Number of observed sources
15- 18 I4 Msun Mobs Total observed mass
20- 24 F5.2 --- chi Slope of observed mass distribution
26- 29 I4 --- Ntot Number estimated of sources
31- 34 I4 Msun Mtot Total estimated mass
36- 39 I4 Msun e_Mtot Uncertainty in Mtot
41- 44 F4.1 pc Rtot Total radius
46- 48 F3.1 pc e_Rtot Uncertainty in Rtot
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Cluster Cluster name
10- 14 F5.1 pc-2 Sdens Stellar surface density
16- 19 F4.1 pc-2 e_Sdens Uncertainty in Sdens
21- 24 F4.2 pc Rcore Radius of core
26- 29 F4.2 pc e_Rcore Uncertainty in Rcore
31- 34 F4.2 --- deltac Density-contrast parameter
36- 38 I3 Myr Tcrmin Crossing time inferior limit
40- 42 I3 Myr Tcrmax Crossing time superior limit
44- 46 F3.1 --- Pimin Dynamical age inferior limit
48- 50 F3.1 --- Pimax Dynamical age superior limit
52- 55 F4.2 --- mbar Mean edge length that is related to the
surface density of the point distribution
57- 60 F4.2 --- e_mbar Uncertainty in mbar
62- 65 F4.2 --- sbar Mean separation in the minimal spanning tree
67- 70 F4.2 --- e_sbar Uncertainty in sbar
72- 75 F4.2 --- Q Fractal parameter Q
77- 80 F4.2 --- e_Q Uncertainty in Q
82- 85 F4.2 --- LambdaMSR Mass segregation ratio
87- 90 F4.2 --- e_LambdaMSR Uncertainty in LambdaMSR
92- 95 F4.2 --- SigmaLDR Local density ratio
97-100 F4.2 --- e_SigmaLDR Uncertainty in SigmaLDR
102-106 F5.3 --- pvalue Significance of the deviation from the
median for al stars
--------------------------------------------------------------------------------
Byte-by-byte Description of file: col205.dat ic2602.dat mrk*.dat ngc*.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 identifier
21- 28 F8.4 deg RAdeg Right ascension (ICRS) at Epoch=2016
30- 35 F6.4 deg e_RAdeg Right ascension error
37- 44 F8.4 deg DEdeg Declination (ICRS) at Epoch=2016
46- 51 F6.4 deg e_DEdeg Declination error
53- 57 F5.3 mas Plx Parallax
59- 63 F5.3 mas e_Plx Error in parallax
65- 72 F8.4 mas/yr pmRA Proper motion along RA, pmRA*cosDE
74- 79 F6.4 mas/yr e_pmRA Uncertainty on pmRA
81- 87 F7.4 mas/yr pmDE Proper motion along DE
89- 94 F6.4 mas/yr e_pmDE Uncertainty on DE
96-100 F5.2 mag Gmag ? Gaia G magnitude
102-106 F5.2 mag BP-RP ? Gaia BP-RP colour
108-112 F5.3 kpc Dmode Distance mode
114-118 F5.3 kpc E_Dmode Dmode superior limit
120-124 F5.3 kpc e_Dmode Dmode inferior limit
126-129 F4.2 --- Pmemb Membership probability
131-134 F4.2 Msun Mass ? Mass
136-139 F4.2 Msun e_Mass ? Mass inferior limit
141-144 F4.2 Msun E_Mass ? Mass superior limit
--------------------------------------------------------------------------------
Acknowledgements:
Annibal Hetem, annibal.hetem(at)gmail.com
(End) Patricia Vannier [CDS] 30-Sep-2024