J/ApJ/913/32 Classifications from Gaia & WISE data (Dorn-Wallenstein+, 2021)
Photometric classifications of evolved massive stars: preparing for the era of
Webb and Roman with machine learning.
Dorn-Wallenstein T.Z., Davenport J.R.A., Huppenkothen D., Levesque E.M.
<Astrophys. J., 913, 32-32 (2021)>
=2021ApJ...913...32D 2021ApJ...913...32D (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, infrared; Optical; Colors; Stars, giant;
Cross identifications
Keywords: Massive stars; Stellar classification; Support vector machine
Infrared photometry; Emission line stars
Abstract:
In the coming years, next-generation space-based infrared
observatories will significantly increase our samples of rare massive
stars, representing a tremendous opportunity to leverage modern
statistical tools and methods to test massive stellar evolution in
entirely new environments. Such work is only possible if the observed
objects can be reliably classified. Spectroscopic observations are
infeasible with more distant targets, and so we wish to determine
whether machine-learning methods can classify massive stars using
broadband infrared photometry. We find that a Support Vector Machine
classifier is capable of coarsely classifying massive stars with
labels corresponding to hot, cool, and emission-line stars with high
accuracy, while rejecting contaminating low-mass giants. Remarkably,
76% of emission-line stars can be recovered without the need for
narrowband or spectroscopic observations. We classify a sample of
∼2500 objects with no existing labels and identify 14 candidate
emission-line objects. Unfortunately, despite the high precision of
the photometry in our sample, the heterogeneous origins of the labels
for the stars in our sample severely inhibit our classifier from
distinguishing classes of stars with more granularity. Ultimately, no
large and homogeneously labeled sample of massive stars currently
exists. Without significant efforts to robustly classify evolved
massive stars-which is feasible given existing data from large all-sky
spectroscopic surveys-shortcomings in the labeling of existing data
sets will hinder efforts to leverage the next generation of space
observatories.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 105 6484 Common names, coordinates, host galaxies, and
Gaia measurements of 6484 putative massive stars
table4.dat 208 6484 Feature values and assigned labels for all stars
in our sample, ordered by Right Ascension
table5.dat 56 79 Common names and coordinates of stars predicted
to be RSGs by the Support Vector Machine (SVM)
classifier (SVC) trained on refined labels
tablea1.dat 69 2550 Common names, coordinates, and predicted labels
of 2550 stars input to the SVC trained on
coarse labels
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
II/328 : AllWISE Data Release (Cutri+ 2013)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
J/A+A/363/L1 : The distance modulus of the LMC (Kovacs, 2000)
J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)
J/AJ/133/2393 : UBVRI phot. in 7 Local Group dwarfs galaxies (Massey+, 2007)
J/ApJ/703/420 : Red supergiants in M31 (Massey+, 2009)
J/A+A/537/A146 : Stellar models with rot. 0.8<M<120, Z=0.014 (Ekstrom+, 2012)
J/MNRAS/440/3430 : SDSS-2MASS-WISE stellar colour locus (Davenport+, 2014)
J/AJ/151/144 : ASPCAP weights for APOGEE chemical elements (Garcia+, 2016)
J/ApJ/841/15 : Synthetic JWST/MIRI fluxes and magnitudes (Jones+, 2017)
J/A+A/615/A78 : Spectral models for binary products (Goetberg+, 2018)
J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)
J/ApJ/863/181 : The fifth catalog of LMC Wolf-Rayet stars (Neugent+, 2018)
J/A+A/616/A175 : Red supergiant stars in the LMC. II. (Yang+, 2018)
J/ApJ/864/111 : HST/ACS one-year observations of M51 stars (Conroy+, 2018)
J/A+A/629/A91 : A source catalog for the SMC (Yang+, 2019)
J/ApJ/889/44 : UKIRT obs. of red supergiants in M31 (Neugent+, 2020)
J/ApJ/893/11 : Massive star variability in M31 from iPTF (Soraisam+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 31 A31 --- Name Common name from Simbad
33- 51 I19 --- Gaia Gaia DR2 source ID
53- 64 F12.8 deg RAdeg Gaia DR2 Right Ascension (ICRS) at Ep=2015.5
66- 77 F12.8 deg DEdeg Gaia DR2 Declination (ICRS) at Ep=2015.5
79- 81 A3 --- Host Host Galaxy ("LMC", 3348 occurrences;
"MW", 2161 occurrences or "SMC", 975 occurrences)
83- 88 F6.3 kpc rest [1.26/29.13]? Estimated distance from
Bailer-Jones+ (2018AJ....156...58B 2018AJ....156...58B, I/347)
90- 94 F5.2 mag Gmag [7.4/17] Gaia DR2 G-band magnitude
96- 99 F4.2 mag AG [0/3.2] Gaia DR2 AG estimate
101- 105 F5.2 mag BP-RP [-0.51/3.8] Gaia DR2 BP-RP color index
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 31 A31 --- Name Common Name from Simbad
33- 37 F5.2 mag GMag [-9.93/-2.9] Absolute magnitude in Gaia G
band
39- 43 F5.2 mag G-J [-5/4.42]? G-J color from Gaia and 2MASS
photometry
45- 49 F5.2 mag J-H [-0.3/4.7]? J-H color from 2MASS
photometry
51- 55 F5.2 mag H-Ks [-0.4/1.2]? H-Ks color from 2MASS
photometry
57- 61 F5.2 mag Ks-W1 [-0.96/2.5]? Ks-W1 color from 2MASS and
WISE photometry
63- 67 F5.2 mag W1-W2 [-0.4/1.2] W1-W2 color from WISE
photometry
69- 73 F5.2 mag W2-W3 [-2.9/6.2] W2-W3 color from WISE
photometry
75- 79 F5.2 mag W3-W4 [-1.3/7.1] W3-W4 color from WISE
photometry
81- 86 F6.2 mag W1Mag [-11.1/-2.2] Absolute magnitude in WISE W1
88- 92 F5.2 [-] logX2rW1 [-1.98/3.2]? Log of reduced χ2, W1
94- 98 F5.2 [-] logEWMW1 [-1.4/1.6]? Log, error-weighted Median
Absolute Deviation, W1
100- 103 F4.2 d-1 nu0W1 [0]? Zero-crossing frequency, W1 (1)
105- 108 F4.2 d logDtW1 [1.7/3.5]? Log, average time between
zero-crossings, W1
110- 113 F4.2 d logSDtW1 [0.19/3]? Log, standard deviation of
zero-crossing times, W1
115- 119 F5.2 [-] logX2rW2 [-2.2/4.4]? Log of reduced χ2, W2
121- 125 F5.2 [-] logEWMW2 [-1.3/1.7]? Log, error-weighted Median
Absolute Deviation, W2
127- 130 F4.2 d-1 nu0W2 [0]? Zero-crossing frequency, W2 (1)
132- 135 F4.2 d logDtW2 [1.79/3.45]? Log, average time between
zero-crossings, W2
137- 142 F6.2 d logSDtW2 [-13/3.1]? Log, standard deviation of
zero-crossing times, W2
144- 148 F5.2 [-] logX2rW1W2 [-3.3/3.1]? Log, reduced χ^2, W1-W2
150- 155 F6.2 [-] logEWMW1W2 [-13.2/1.3]? Log, error-weighted Median
Absolute Deviation, W1-W2
157- 160 F4.2 d-1 nu0W1W2 [0]? Zero-crossing frequency, W1-W2 (1)
162- 165 F4.2 d logDtW1W2 [2/3.5]? Log, average time between
zero-crossings, W1-W2
167- 172 F6.2 d logSDtW1W2 [-13/3.1]? Log, standard deviation of
zero-crossing times, W1-W2
174- 190 A17 --- Label Label from SIMBAD (2)
192- 208 A17 --- cLabel Coarse Label (3)
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Note (1): Frequency of zero-crossings of the first derivative of the spline
interpolant.
Note (2): Label (see Section 2.1 for further details) as follows:
C/S/Giant = Luminosity class III, C/S/Giant (118 occurrences)
EvolvedOBA = Evolved O, B or A; Class III or IV (409 occurrences)
LBV = luminous blue variable (8 occurrences)
MainSequenceOBA = Main sequence O, B or A (187 occurrences)
Misc. Variable = Miscellaneous variable (322 occurrences)
OBA = O, B or A star (915 occurrences)
OBAe = non-OB[e] stars with spectral types including an "e"
(383 occurrences)
OB[e] = OB[e] star (12 occurrences)
RSG = red supergiant (847 occurrences)
SupergiantOBA = Supergiant O, B or A; class I (798 occurrences)
Unknown/Candidate = Unknown/candidate (2228 occurrences)
WR = Wolf-Rayet star (37 occurrences)
YSG = yellow supergiant (212 occurrences)
Yellow Dwarf = yellow dwarf (8 occurrences)
Note (3): Coarse label as follows:
Contaminant = C/S/Giant stars and yellow dwarfs (126 occurrences)
Cool = RSGs and YSGs (1059 occurrences)
EM = Emission: W-R stars, LBVs, and both OB[e] and OBAe stars
(440 occurrences)
Hot = all classes of OBA stars excluding OB[e] and OBAe
(2309 occurrences)
Unknown/Candidate = miscellaneous variables and unknown/candidates
(2550 occurrences)
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 30 A30 --- Name Common Name from Simbad
32- 43 F12.8 deg RAdeg Gaia DR2 Right Ascension (ICRS) at Ep=2015.5
45- 56 F12.8 deg DEdeg Gaia DR2 Declination (ICRS) at Ep=2015.5
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 31 A31 --- Name Common Name from Simbad
33- 44 F12.8 deg RAdeg Gaia DR2 Right Ascension (ICRS) at Ep=2015.5
46- 57 F12.8 deg DEdeg Gaia DR2 Declination (ICRS) at Ep=2015.5
59- 69 A11 --- Label Predicted Coarse Label (1)
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Note (1): Lable as follows:
Hot = all classes of OBA stars excluding OB[e] and OBAe
(2472 occurrences)
Cool = RSGs and YSGs (63 occurrences)
EM = Emission: W-R stars, LBVs, and both OB[e] and OBAe stars
(14 occurrences)
Contaminant = C/S/Giant stars and yellow dwarfs (1 occurrence)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Nov-2022