J/other/SCPMA/57.176 Carbon stars and DZ white dwarfs in SDSS spectra (Si+ 2014)
Search for carbon stars and DZ white dwarfs in SDSS spectra survey
through machine learning.
Si J.M., Luo A.L., Li Y.B., Zhang J.N., Wei P., Wu Y.H., Wu F.C., Zhao Y.H.
<Sci. China Phys., Mecha., Astro., 57, 176-186 (2014)>
=2014SCPMA..57..176S 2014SCPMA..57..176S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, white dwarf ; Stars, carbon
Keywords: machine learning - label propagation - carbon stars - DZ white dwarfs
Abstract:
Carbon stars and DZ white dwarfs are two types of rare objects in the
Galaxy. In this paper, we have applied the label propagation algorithm
to search for these two types of stars from Data Release Eight (DR8)
of the Sloan Digital Sky Survey (SDSS), which is verified to be
efficient by calculating precision and recall. From nearly two million
spectra including stars, galaxies and QSOs, we have found 260 new
carbon stars in which 96 stars have been identified as dwarfs and 7
identified as giants, and 11 composition spectrum systems (each of
them consists of a white dwarf and a carbon star). Similarly, using
the label propagation method, we have obtained 29 new DZ white dwarfs
from SDSS DR8. Compared with PCA reconstructed spectra, the 29
findings are typical DZ white dwarfs. We have also investigated their
proper motions by comparing them with proper motion distribution of
9374 white dwarfs, and found that they satisfy the current observed
white dwarfs by SDSS generally have large proper motions. In addition,
we have estimated their effective temperatures by fitting the
polynomial relationship between effective temperature and g-r color of
known DZ white dwarfs, and found 12 of the 29 new DZ white dwarfs are
cool, in which nine are between 6000K and 6600K, and three are
below 6000K.
Description:
We have applied the label propagation algorithm to search for carbon
stars from 656801 star, 1003596 galaxy and 182803 QSO spectra of SDSS
DR8 respectively, and found 260 new carbon stars and 11 composition
spectrum systems, each of which consists of a white dwarf and a carbon
star.
We have applied the label propagation algorithm to search for DZ white
dwarfs from all spectra of SDSS DR8, and found 29 new DZ white dwarfs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 98 18 New carbon star catalog (incomplete table)
table4.dat 70 14 Composition spectrum systems
table5.dat 93 29 New DZ white dwarfs
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 24 A24 --- SDSS SDSS name (SDSS JHHMMSS.ss+DDMMSS.s)
26- 30 F5.2 mag umag ?=- SDSS u magnitude (1)
32- 36 F5.2 mag gmag ?=- SDSS g magnitude (1)
38- 42 F5.2 mag rmag ?=- SDSS r magnitude (1)
44- 48 F5.2 mag imag ?=- SDSS i magnitude (1)
50- 54 F5.2 mag zmag ?=- SDSS z magnitude (1)
56- 60 F5.2 mag Jmag ?=- 2MASS J magnitude (1)
62- 66 F5.2 mag Hmag ?=- 2MASS H magnitude (1)
68- 72 F5.2 mag Kmag ?=- 2MASS K magnitude (1)
74- 79 F6.2 mas/yr pmRA ?=- Proper motion along RA, pmRA*cosDE (1)
81- 86 F6.2 mas/yr pmDE ?=- Proper motion along DE (1)
88- 91 F4.2 mas/yr e_pmRA ?=- rms uncertainty on pmRA (1)
93- 96 F4.2 mas/yr e_pmDE ?=- rms uncertainty on pmDE (1)
98 A1 --- Class Classification (2)
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Note (1): "---" indicates corresponding parameters, for example, magnitude or
proper motion, are not available
Note (2): Classificaiton code as follows:
d = indicates identified dwarf carbon star
g = indicates identified giant carbon star
u = indicates uncertain
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 24 A24 --- SDSS SDSS name (SDSS JHHMMSS.ss+DDMMSS.s)
25 A1 --- n_SDSS [a] a for objects observed twice
27- 30 I4 --- Plate SDSS Plate identifier
32- 36 I5 --- MJD SDSS MJD identifier
38- 40 I3 --- Fiber SDSS Fiber identifier
42- 46 F5.2 mag umag ?=- SDSS u magnitude
48- 52 F5.2 mag gmag ?=- SDSS g magnitude
54- 58 F5.2 mag rmag ?=- SDSS r magnitude
60- 64 F5.2 mag imag ?=- SDSS i magnitude
66- 70 F5.2 mag zmag ?=- SDSS z magnitude
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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- 24 A24 --- SDSS SDSS name (SDSS JHHMMSS.ss+DDMMSS.s)
25 A1 --- n_SDSS [a] a:Proper motion is provided by PPMXL catalog
27- 31 F5.2 mag umag ?=- SDSS u magnitude (1)
33- 37 F5.2 mag gmag ?=- SDSS g magnitude (1)
39- 43 F5.2 mag rmag ?=- SDSS r magnitude (1)
45- 49 F5.2 mag imag ?=- SDSS i magnitude (1)
51- 55 F5.2 mag zmag ?=- SDSS z magnitude (1)
57- 61 I5 K Teff Effective temperature
63- 69 F7.2 mas/yr pmRA ?=- Proper motion along RA, pmRA&cosDE (1)
71- 76 F6.2 mas/yr pmDE ?=- Proper motion along DE (1)
78- 81 F4.2 mas/yr e_pmRA ?=- rms uncertainty on pmRA (1)
83- 86 F4.2 mas/yr e_pmDE ?=- rms uncertainty on pmDE (1)
88- 93 F6.2 mas/yr pm ?=- Total proper motion
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Note (1): "---" indicates corresponding parameters, for example, magnitude or
proper motion, are not available
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 26-Jun-2021