J/A+A/477/165 Nearby open clusters tidal radii and masses (Piskunov+, 2008)
Tidal radii and masses of open clusters.
Piskunov A.E., Schilbach E., Kharchenko N.V., Roeser S., Scholz R.-D.
<Astron. Astrophys. 477, 165 (2008)>
=2008A&A...477..165P 2008A&A...477..165P
ADC_Keywords: Clusters, open ; Morphology
Keywords: Galaxy: open clusters and associations: general -
solar neighbourhood - Galaxy: stellar content
Abstract:
In a previous paper we obtained King's parameters for 236 of 650
Galactic open clusters identified in the ASCC-2.5 (Kharchenko, 2001,
Cat. I/280). Our aims is the estimate tidal radii by use of
observable parameters available for all clusters. Bias-free results
are required. We use methods of stellar statistics and develop a
semi-empirical model of open clusters.
Description:
The table presents tidal radii and masses of 650 Galactic open
clusters. The tidal radii are derived from a relation between a
semi-major axis A of the density distributions of cluster members and
fitted King radii (J/A+A/468/151). The cluster masses are found from
cluster tidal radii assuming that the latter are good approximations
of limiting radii for local clusters moving at nearly circular orbits.
The clusters are a sample of the Catalogue of Open Cluster Data and
their members are selected from the high-precision, homogeneous
all-sky catalogue ASCC-2.5 (Kharchenko, 2001, Cat. I/280). The
clusters in the table are sorted according to their order in the COCD.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 124 650 Tidal radii and masses for 650 open clusters
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See also:
I/280 : All-sky Compiled Cat. of 2.5 million stars (Kharchenko, 2001)
J/A+A/438/1163 : Catalogue of Open cluster Data (COCD) (Kharchenko+, 2005)
J/A+A/440/403 : 109 new Galactic open clusters (COCD1) (Kharchenko+, 2005)
J/A+A/468/151 : Nearby open clusters radii and masses (Piskunov+, 2007)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- COCD (1-520, 1001-1130) COCD number
7- 23 A17 --- Name Cluster designation (NGC, IC or other) (1)
25- 31 F7.2 deg GLON Galactic longitude
32- 38 F7.2 deg GLAT Galactic latitude
39- 46 F8.3 mag DistMod Distance modulus
47- 52 F6.2 mag E(B-V) B-V Colour-excess
53- 58 I6 pc Dist Distance
59- 64 F6.2 [yr] logt Logarithm of age
65- 70 F6.1 pc rt ?=-9.9 Tidal radius
71- 76 F6.1 pc e_rt ?=-9.9 rms error rt
77- 85 F9.3 [solMass] logM ?=-9.999 Logarithm of cluster mass
86- 94 F9.3 [solMass] e_logM ?=-9.999 rms error of logM
95-100 F6.1 pc rtA Tidal radius derived from semi-major axis A
101-106 F6.1 pc e_rtA rms error of rtA
107-115 F9.3 [solMass] logMA Log of Cluster mass from semi-major axis A
116-124 F9.3 [solMass] e_logMA rms error of logMA
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Note (1): There are clusters which overlap in the plane of the sky some
of which also have common members. The most prominent example is
the "double cluster" h and chi Per (COCD numbers 29 and 30). Their
semi-major axes A are overestimated due to the relatively large number
of common members, and so are their individual tidal radii and masses.
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Acknowledgements:
Ralf-Dieter Scholz, rdscholz(at)aip.de
(End) Patricia Vannier [CDS] 03-Dec-2007