J/MNRAS/478/4416 Classifying galaxy spectra at 0.5<z<1 (Rahmani+, 2018)
Classifying galaxy spectra at 0.5 < z < 1 with self-organizing maps.
Rahmani S., Teimoorinia H., Barmby P.
<Mon. Not. R. Astron. Soc., 478, 4416-4432 (2018)>
=2018MNRAS.478.4416R 2018MNRAS.478.4416R (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra
Keywords: galaxies: high-redshift - galaxies: spectra - methods: observational -
methods: statistical - methods: data analysis
Abstract:
The spectrum of a galaxy contains information about its physical
properties. Classifying spectra using templates helps to elucidate the
nature of a galaxy's energy sources. In this paper, we investigate the
use of self-organizing maps in classifying galaxy spectra against
templates. We trained semi-supervised self-organizing map networks
using a set of templates covering the wavelength range from far
ultraviolet to near-infrared. The trained networks were used to
classify the spectra of a sample of 142 galaxies with 0.5<z<1 and
the results compared to classifications performed using K-means
clustering, a supervised neural network, and chi-squared minimization.
Spectra corresponding to quiescent galaxies were more likely to be
classified similarly by all methods while starburst spectra showed
more variability. Compared to classification using chi-squared
minimization or the supervised neural network, the galaxies classed
together by the self-organizing map had more similar spectra. The
class ordering provided by the 1D self-organizing maps corresponds to
an ordering in physical properties, a potentially important feature
for the exploration of large data sets.
Description:
Self-organizing maps can be used to classify celestial objects (e.g.
stars, quasars, spectra of galaxies, light curves, etc.). In this
work, we presented a detailed comparison between different types of
self-organizing maps and other methods used to classify galaxy
spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 94 142 Properties of best-fitting models created by
Teimoorinia (2012AJ....144..172T 2012AJ....144..172T)
spectra.dat 1175 630 Spectra of the 142 galaxies
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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- 4 A4 --- ID Internal galaxy identifier (G1-G142)
6- 28 A23 --- GOODS GOODS name (GDS-JHHMMS.ss+DDMMSS.s)
30- 34 F5.3 --- z Redshift
36- 40 F5.2 [Msun] logM* Stellar mass
42- 45 F4.2 [Msun] e_logM* rms uncertainty on logM*
47- 51 F5.2 Gyr Age Age
53- 56 F4.2 Gyr e_Age rms uncertainty on Age
58- 62 F5.2 [Gyr-1] logsSFR Specific star formation rate
64- 67 F4.2 [Gyr-1] e_logsSFR rms uncertainty on logsSFR
69- 73 F5.2 --- log(fburst) Mass fraction of young single population
(SP) model
75- 78 F4.2 --- e_log(fburst) rms uncertainty on log(frac-burst)
80- 83 F4.2 mag A(FUV) Attenuation at 1500Å
85- 88 F4.2 mag e_A(FUV) rms uncertainty on A(FUV)
90- 94 A5 --- T12Class Teimoorinia (2012AJ....144..172T 2012AJ....144..172T)
classification
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Byte-by-byte Description of file: spectra.dat
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Bytes Format Units Label Explanations
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1- 4 I4 0.1nm lambda [1236/7526] Wavelength
6- 12 F7.5 --- G1 G1 galaxy normalized flux
14- 21 F8.6 --- G2 G2 galaxy normalized flux
23- 29 F7.5 --- G3 G3 galaxy normalized flux
31- 37 F7.5 --- G4 G4 galaxy normalized flux
39- 45 F7.5 --- G5 G5 galaxy normalized flux
47- 53 F7.5 --- G6 G6 galaxy normalized flux
55- 62 F8.6 --- G7 G7 galaxy normalized flux
64- 70 F7.5 --- G8 G8 galaxy normalized flux
72- 79 F8.6 --- G9 G9 galaxy normalized flux
81- 87 F7.5 --- G10 G10 galaxy normalized flux
89- 95 F7.5 --- G11 G11 galaxy normalized flux
97- 103 F7.5 --- G12 G12 galaxy normalized flux
105- 111 F7.5 --- G13 G13 galaxy normalized flux
113- 120 F8.6 --- G14 G14 galaxy normalized flux
122- 128 F7.5 --- G15 G15 galaxy normalized flux
130- 136 F7.5 --- G16 G16 galaxy normalized flux
138- 144 F7.5 --- G17 G17 galaxy normalized flux
146- 152 F7.5 --- G18 G18 galaxy normalized flux
154- 160 F7.5 --- G19 G19 galaxy normalized flux
162- 168 F7.5 --- G20 G20 galaxy normalized flux
170- 176 F7.5 --- G21 G21 galaxy normalized flux
178- 184 F7.5 --- G22 G22 galaxy normalized flux
186- 192 F7.5 --- G23 G23 galaxy normalized flux
194- 200 F7.5 --- G24 G24 galaxy normalized flux
202- 208 F7.5 --- G25 G25 galaxy normalized flux
210- 216 F7.5 --- G26 G26 galaxy normalized flux
218- 224 F7.5 --- G27 G27 galaxy normalized flux
226- 232 F7.5 --- G28 G28 galaxy normalized flux
234- 241 F8.6 --- G29 G29 galaxy normalized flux
243- 249 F7.5 --- G30 G30 galaxy normalized flux
251- 257 F7.5 --- G31 G31 galaxy normalized flux
259- 266 F8.6 --- G32 G32 galaxy normalized flux
268- 274 F7.5 --- G33 G33 galaxy normalized flux
276- 282 F7.5 --- G34 G34 galaxy normalized flux
284- 290 F7.5 --- G35 G35 galaxy normalized flux
292- 299 F8.6 --- G36 G36 galaxy normalized flux
301- 307 F7.5 --- G37 G37 galaxy normalized flux
309- 315 F7.5 --- G38 G38 galaxy normalized flux
317- 323 F7.5 --- G39 G39 galaxy normalized flux
325- 331 F7.5 --- G40 G40 galaxy normalized flux
333- 339 F7.5 --- G41 G41 galaxy normalized flux
341- 347 F7.5 --- G42 G42 galaxy normalized flux
349- 356 F8.6 --- G43 G43 galaxy normalized flux
358- 365 F8.6 --- G44 G44 galaxy normalized flux
367- 373 F7.5 --- G45 G45 galaxy normalized flux
375- 382 F8.6 --- G46 G46 galaxy normalized flux
384- 390 F7.5 --- G47 G47 galaxy normalized flux
392- 398 F7.5 --- G48 G48 galaxy normalized flux
400- 407 F8.6 --- G49 G49 galaxy normalized flux
409- 416 F8.6 --- G50 G50 galaxy normalized flux
418- 425 F8.6 --- G51 G51 galaxy normalized flux
427- 433 F7.5 --- G52 G52 galaxy normalized flux
435- 441 F7.5 --- G53 G53 galaxy normalized flux
443- 449 F7.5 --- G54 G54 galaxy normalized flux
451- 458 F8.6 --- G55 G55 galaxy normalized flux
460- 466 F7.5 --- G56 G56 galaxy normalized flux
468- 474 F7.5 --- G57 G57 galaxy normalized flux
476- 483 F8.6 --- G58 G58 galaxy normalized flux
485- 491 F7.5 --- G59 G59 galaxy normalized flux
493- 500 F8.6 --- G60 G60 galaxy normalized flux
502- 509 F8.6 --- G61 G61 galaxy normalized flux
511- 518 F8.6 --- G62 G62 galaxy normalized flux
520- 526 F7.5 --- G63 G63 galaxy normalized flux
528- 534 F7.5 --- G64 G64 galaxy normalized flux
536- 543 F8.6 --- G65 G65 galaxy normalized flux
545- 551 F7.5 --- G66 G66 galaxy normalized flux
553- 559 F7.5 --- G67 G67 galaxy normalized flux
561- 567 F7.5 --- G68 G68 galaxy normalized flux
569- 576 F8.6 --- G69 G69 galaxy normalized flux
578- 585 F8.6 --- G70 G70 galaxy normalized flux
587- 593 F7.5 --- G71 G71 galaxy normalized flux
595- 602 F8.6 --- G72 G72 galaxy normalized flux
604- 610 F7.5 --- G73 G73 galaxy normalized flux
612- 619 F8.6 --- G74 G74 galaxy normalized flux
621- 628 F8.6 --- G75 G75 galaxy normalized flux
630- 637 F8.6 --- G76 G76 galaxy normalized flux
639- 646 F8.6 --- G77 G77 galaxy normalized flux
648- 655 F8.6 --- G78 G78 galaxy normalized flux
657- 663 F7.5 --- G79 G79 galaxy normalized flux
665- 672 F8.6 --- G80 G80 galaxy normalized flux
674- 680 F7.5 --- G81 G81 galaxy normalized flux
682- 688 F7.5 --- G82 G82 galaxy normalized flux
690- 696 F7.5 --- G83 G83 galaxy normalized flux
698- 704 F7.5 --- G84 G84 galaxy normalized flux
706- 712 F7.5 --- G85 G85 galaxy normalized flux
714- 721 F8.6 --- G86 G86 galaxy normalized flux
723- 729 F7.5 --- G87 G87 galaxy normalized flux
731- 737 F7.5 --- G88 G88 galaxy normalized flux
739- 745 F7.5 --- G89 G89 galaxy normalized flux
747- 753 F7.5 --- G90 G90 galaxy normalized flux
755- 761 F7.5 --- G91 G91 galaxy normalized flux
763- 769 F7.5 --- G92 G92 galaxy normalized flux
771- 777 F7.5 --- G93 G93 galaxy normalized flux
779- 785 F7.5 --- G94 G94 galaxy normalized flux
787- 793 F7.5 --- G95 G95 galaxy normalized flux
795- 801 F7.5 --- G96 G96 galaxy normalized flux
803- 809 F7.5 --- G97 G97 galaxy normalized flux
811- 817 F7.5 --- G98 G98 galaxy normalized flux
819- 825 F7.5 --- G99 G99 galaxy normalized flux
827- 834 F8.6 --- G100 G100 galaxy normalized flux
836- 842 F7.5 --- G101 G101 galaxy normalized flux
844- 850 F7.5 --- G102 G102 galaxy normalized flux
852- 858 F7.5 --- G103 G103 galaxy normalized flux
860- 866 F7.5 --- G104 G104 galaxy normalized flux
868- 874 F7.5 --- G105 G105 galaxy normalized flux
876- 883 F8.6 --- G106 G106 galaxy normalized flux
885- 891 F7.5 --- G107 G107 galaxy normalized flux
893- 900 F8.6 --- G108 G108 galaxy normalized flux
902- 908 F7.5 --- G109 G109 galaxy normalized flux
910- 916 F7.5 --- G110 G110 galaxy normalized flux
918- 924 F7.5 --- G111 G111 galaxy normalized flux
926- 932 F7.5 --- G112 G112 galaxy normalized flux
934- 940 F7.5 --- G113 G113 galaxy normalized flux
942- 948 F7.5 --- G114 G114 galaxy normalized flux
950- 956 F7.5 --- G115 G115 galaxy normalized flux
958- 964 F7.5 --- G116 G116 galaxy normalized flux
966- 972 F7.5 --- G117 G117 galaxy normalized flux
974- 981 F8.6 --- G118 G118 galaxy normalized flux
983- 989 F7.5 --- G119 G119 galaxy normalized flux
991- 997 F7.5 --- G120 G120 galaxy normalized flux
999-1005 F7.5 --- G121 G121 galaxy normalized flux
1007-1013 F7.5 --- G122 G122 galaxy normalized flux
1015-1021 F7.5 --- G123 G123 galaxy normalized flux
1023-1029 F7.5 --- G124 G124 galaxy normalized flux
1031-1037 F7.5 --- G125 G125 galaxy normalized flux
1039-1045 F7.5 --- G126 G126 galaxy normalized flux
1047-1053 F7.5 --- G127 G127 galaxy normalized flux
1055-1061 F7.5 --- G128 G128 galaxy normalized flux
1063-1069 F7.5 --- G129 G129 galaxy normalized flux
1071-1077 F7.5 --- G130 G130 galaxy normalized flux
1079-1085 F7.5 --- G131 G131 galaxy normalized flux
1087-1093 F7.5 --- G132 G132 galaxy normalized flux
1095-1102 F8.6 --- G133 G133 galaxy normalized flux
1104-1110 F7.5 --- G134 G134 galaxy normalized flux
1112-1119 F8.6 --- G135 G135 galaxy normalized flux
1121-1127 F7.5 --- G136 G136 galaxy normalized flux
1129-1135 F7.5 --- G137 G137 galaxy normalized flux
1137-1143 F7.5 --- G138 G138 galaxy normalized flux
1145-1151 F7.5 --- G139 G139 galaxy normalized flux
1153-1159 F7.5 --- G140 G140 galaxy normalized flux
1161-1167 F7.5 --- G141 G141 galaxy normalized flux
1169-1175 F7.5 --- G142 G142 galaxy normalized flux
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-Oct-2021