J/A+A/392/1129 Automatic observation rendering (AMORE) (Ng, 2002)
Automatic observation rendering (AMORE).
I. On a synthetic stellar population's colour-magnitude diagram.
Ng Y.K., Brogt E., Chiosi C., Bertelli G.
<Astron. Astrophys. 392, 1129 (2002)>
=2002A&A...392.1129N 2002A&A...392.1129N
ADC_Keywords: Models, evolutionary ; Photometry
Keywords: methods: data analysis, numerical - stars: HR-diagram, statistics
Abstract:
A new method, AMORE (AutoMatic Observation REnderer) - based on a
genetic algorithm optimizer, is presented for the automated study of
colour-magnitude diagrams. The method combines several stellar
population synthesis tools developed in the last decade by or in
collaboration with the Padova group. Our method is able to recover,
within the uncertainties, the parameters - distance, extinction, age,
metallicity, index of a power-law initial mass function and the index
of an exponential star formation rate - from a reference synthetic
stellar population. No a priori information is inserted to recover the
parameters, which is done simultaneously and not one at a time.
Examples are given to demonstrate and to better understand biases in
the results, if one of the input parameters is deliberately set fixed
to a non-optimum value.
Description:
Tablea1.dat provides AMORE with the test population as specified in
Sect. 4.3.1. See 2.6.2, 2.6.3, 2.6.4, 2.6.5 and 4.2 for additional
details.
Tablea2.dat contains the results of running AMORE with one of the
astrophysical parameters fixed at its original
value. These tests provide an indication about the influence of one
parameter on the retrieval of the remaining parameters, see Sects.
4.3.3 and 5.3 for additional details.
Tablea3.dat contains the results of running AMORE with one of the
parameters fixed at one sigma from its original value. These tests
provide an indication about the influence of one parameter on the
retrieval of the remaining parameters - in particular, how the
remaining parameters balance this mis-match by moving away from their
optimal value (see Sects. 4.3.4 and 5.4 of the paper for additional
details).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 38 163 AMORE results with the test population as
specified in Sect. 4.3.1 of the paper
tablea2.dat 85 48 Results of running AMORE with one of the
astrophysical parameters fixed at its original
value
tablea3.dat 88 90 AMORE with one of the parameters fixed at one
sigma from its original value
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Nmodel [1/162] Model number
5- 8 F4.2 --- pcross crossover probability
10- 13 F4.2 --- rcross multi-point crossover rate
15- 18 F4.2 --- rbrood amount of offspring two parents can have
20- 22 F3.1 --- pcreep creep mutation rate
24- 26 F3.1 --- pcorr correlated mutation rate
28- 34 F7.5 --- fA Fitness value
36- 38 I3 --- Gen Generation number (1)
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Note (1): The generation number indicates at which generation the resulting
fitness value fA obtained with AMORE first emerged.
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Param Parameter name
14- 15 I2 --- Nmodel Model number
17- 23 F7.5 --- fA Fitness value
25- 31 F7.5 pc logd Distance
33- 38 F6.3 mag AV Extinction
40- 46 F7.5 [Gyr] logtl Lower age limit
48- 55 F8.5 [Gyr] logth Upper age limit
57- 64 F8.5 [Sun] [Z]l Lower metallicity limit
66- 72 F7.5 [Sun] [Z]h Upper metallicity limit
74- 78 F5.3 --- alpha Slope for the Initial Mass Function power-law
80- 85 F6.3 --- beta Index for the Star Formation Rate exponential
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Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 12 A12 --- Param Parameter name
14- 15 I2 --- Offset Offset in σ units
17- 18 I2 --- Nmodel Model number
20- 26 F7.5 --- fA ? Fitness value
28- 34 F7.5 pc logd ? Distance
36- 41 F6.3 mag AV ? Extinction
43- 49 F7.5 [Gyr] logtl ? Lower age limit
51- 58 F8.5 [Gyr] logth ? Upper age limit
60- 67 F8.5 [Sun] [Z]l ? Lower metallicity limit
69- 75 F7.5 [Sun] [Z]h ? Upper metallicity limit
77- 81 F5.3 --- alpha ? Slope for the Initial Mass Function power-law
83- 88 F6.3 --- beta ? Index for the Star Formation Rate exponential
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History:
From electronic version of the journal
(End) Patricia Bauer [CDS] 09-Sep-2002