J/A+A/538/A76 Automatic stellar spectral classification (Navarro+, 2012)
Automatic spectral classification of stellar spectra with low signal-to-noise
ratio using artificial neural networks.
Navarro S.G., Corradi R.L.M., Mampaso A.
<Astron. Astrophys., 538, A76 (2012)>
=2012A&A...538A..76N 2012A&A...538A..76N
ADC_Keywords: Planetary nebulae ; MK spectral classification
Keywords: methods: data analysis - planetary nebulae: general -
astronomical databases: miscellaneous
Abstract:
As part of a project aimed at deriving extinction-distances for
thirty-five planetary nebulae, spectra of a few thousand stars were
analyzed to determine their spectral type and luminosity class.
We present here the automatic spectral classification process used to
classify stellar spectra. This system can be used to classify any
other stellar spectra with similar or higher signal-to-noise ratios.
Spectral classification was performed using a system of artificial
neural networks that were trained with a set of line-strength indices
selected among the spectral lines most sensitive to temperature and
the best luminosity tracers. The training and validation processes of
the neural networks are discussed and the results of additional
validation probes, designed to ensure the accuracy of the spectral
classification, are presented.
Description:
More than 2000 stars distributed in the field of view of 35 planetary
nebulae, and 31 stars from the spectral catalog of Jacoby et al.
(1984, Cat. III/92) were observed with the LDSS2 (Low Dispersion
Survey Spectrograph) at the William Herschel Telescope (WHT) on La
Palma, Spain.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 161 Radial velocity and S/N of the stars in the
JHC (Jacoby et al., Cat. III/92) catalog
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See also:
III/92 : A Library of Stellar Spectra (Jacoby+ 1984)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- n_JHC [*] * for stars observed also with the same
instrumentation as our program stars
2- 4 A3 --- --- [jhc]
5- 7 I3 --- JHC JHC number (Cat. III/92) <[JHC84] NNN> in Simbad
9- 18 A10 --- Name Name of the object
20- 27 A8 --- SpT JHC MK spectral classification
29- 32 I4 --- iSpT Numerical code for the adopted spectral type (1)
34 I1 --- LC [1/5] Adopted luminosity class (numeric class)
36- 39 I4 km/s RVcor Corrected radial velocity
41- 43 I3 --- S/N Signal-to-noise ratio
45- 72 A28 --- Com Comments
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Note (1): The spectral type is coded in numerical form, where 2000
corresponds to B0 type stars, 3000 to A0 stars, etc., and one
spectral subtype corresponds to a hundred step. In this way,
an F5 type corresponds to 4500, while 7600 indicates a M6 star.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 17-Apr-2012