J/AJ/141/189 Classifiers for star/galaxy separation (Vasconcellos+, 2011)
Decision tree classifiers for star/galaxy separation.
Vasconcellos E.C., De Carvalho R.R., Gal R.R., Labarbera F.L.,
Capelato H.V., Frago Campos Velho H., Trevisan M., Ruiz R.S.R.
<Astron. J., 141, 189 (2011)>
=2011AJ....141..189V 2011AJ....141..189V
ADC_Keywords: Surveys ; Models ; Morphology
Keywords: catalogs - methods: data analysis - surveys -
virtual observatory tools
Abstract:
We study the star/galaxy classification efficiency of 13 different
decision tree algorithms applied to photometric objects in the Sloan
Digital Sky Survey Data Release Seven (SDSS-DR7). Each algorithm is
defined by a set of parameters which, when varied, produce different
final classification trees. We extensively explore the parameter space
of each algorithm, using the set of 884,126 SDSS objects with
spectroscopic data as the training set. The efficiency of star-galaxy
separation is measured using the completeness function.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 31 70555868 Star/galaxy classification provided by SDSS
and by our FT Decision Tree
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
http://www.sdss.org : SDSS Home Page
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 18 I18 --- SDSS SDSS object identification number
20- 25 F6.3 mag rmag SDSS r band model magnitude
27 I1 --- Typer [0/8] SDSS classification using r band alone (1)
29 I1 --- Type [0/8] SDSS classification using all 5 bands (1)
31 I1 --- FT [1/2] FT decision tree classification
1=star; 2=galaxy
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Note (1): The type (class) is numbered as follows:
0 = Unknown: Object type is not known
3 = Galaxy: An extended object composed of many stars and other matter
6 = Star: A a self-luminous gaseous celestial body
8 = Sky: Blank sky spectrogram (no objects in this arcsecond area)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 14-Sep-2012