J/MNRAS/428/2321 Abundances of open cluster stars (Mitschang+, 2013)
Quantifying chemical tagging: towards robust group finding in the Galaxy.
Mitschang A.W., De Silva G., Sharma S., Zucker D.B.
<Mon. Not. R. Astron. Soc., 428, 2321-2332 (2013)>
=2013MNRAS.428.2321M 2013MNRAS.428.2321M
ADC_Keywords: Clusters, open ; Abundances
Keywords: methods: statistical - techniques: miscellaneous - stars: abundances -
open clusters and associations: general
Abstract:
The first generation of large-scale chemical tagging surveys, in
particular the High Efficiency and Resolution Multi-Element
Spectrograph (HERMES)/Galactic Archaeology with HERMES million star
survey, promises to vastly expand our understanding of the chemical
and dynamical evolution of the Galaxy. This, however, is contingent on
our ability to confidently perform chemical tagging on such a large
data set. Chemical homogeneity has been observed across a range of
elements within several Galactic open clusters, yet the level to which
this is the case globally, and particularly in comparison to the
scatter across clusters themselves, is not well understood. The
patterns of elements in coeval cluster members, occupying a complex
chemical abundance space, are rooted in the evolution, ultimately the
nature of the very late stages, of early generations of stars. The
current astrophysical models of such stages are not yet sufficient to
explain all observations, combining with our significant gaps in the
understanding of star formation, makes this a difficult arena to
tackle theoretically. Here, we describe a robust pair-wise metric used
to gauge the chemical difference between two stellar components. This
metric is then applied to a data base of high-resolution literature
abundance sources to derive a function describing the probability that
two stars are of common evolutionary origin. With this cluster
probability function, it will be possible to report a confidence,
grounded in empirical observational evidence, with which clusters are
detected, independent of the group finding methods. This formulation
is also used to probe the role of chemical dimensionality, and that of
individual chemical species, on the ability of chemical tagging to
differentiate coeval groups of stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 73 287 List of studied stars
table3.dat 47 2775 Literature abundance data base
refs.dat 85 21 References
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See also:
B/ocl : Optically visible open clusters and Candidates (Dias+ 2002-2013)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Simbad Right ascension (J2000)
4- 5 I2 min RAm Simbad Right ascension (J2000)
7- 11 F5.2 s RAs Simbad Right ascension (J2000)
13 A1 --- DE- Simbad Declination sign (J2000)
14- 15 I2 deg DEd Simbad Declination (J2000)
17- 18 I2 arcmin DEm Simbad Declination (J2000)
20- 23 F4.1 arcsec DEs Simbad Declination (J2000)
25- 51 A27 --- SName Simbad name
53- 60 A8 --- Cluster Cluster name
62- 73 A12 --- Star Star name as given in source text
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Cluster Cluster name
10- 11 I2 --- CID [4/50] Unique ID of cluster (per study)
in database (1)
13- 24 A12 --- Star Star name as given in source text (2)
26- 29 I4 --- SID [700/1250] Unique ID of star (per CID)
in database (1)
31 A1 --- Src Reference code in refs.dat file
33- 34 A2 --- El Element species
38- 42 F5.2 [Sun] Abund X/Fe abundance relative to Solar (Fe/H for Fe)
44- 47 F4.2 [Sun] e_Abund ? Tabulated error on abundance
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Note (1): Because there are multiple studies of individual clusters, the unique
cluster ID, or CID, marks a single cluster in a single study. Likewise, the
SID, marks a single star of a particular cluster study. In other words, to
select all data from M67, one could select the cluster field.
However to select data from the Pace et al. (2008, Cat. J/A+A/489/403) study,
one should select on CID=30. To get all elements of a particular star,
similarly select on SID.
Note (2): NGC6791 se49 is NGC6791 1349, HD434535 seems to be HD285773.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1 A1 --- Ref Reference code
3- 21 A19 --- BibCode BibCode
23- 45 A23 --- Aut Author's name
47- 85 A39 --- Com Comments
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 31-Jan-2014