J/ApJS/257/65 Cataclysmic variables from LAMOST DR6 (Sun+, 2021)
A catalog of 323 cataclysmic variables from LAMOST DR6.
Sun Y., Cheng Z., Ye S., Ding R., Peng Y., Zhang J., Huo Z., Cui W.,
Wang X., Shi J., Lin J., Wu C., Li L., Feng S., Yu Y., Ma X., Li X., Liu C.,
Zhang Z., Shao Z.
<Astrophys. J. Suppl. Ser., 257, 65 (2021)>
=2021ApJS..257...65S 2021ApJS..257...65S
ADC_Keywords: Binaries, cataclysmic; Novae; Stars, variable; Magnitudes; Optical
Keywords: Semi-detached binary stars ; Nova-like variable stars ; Novae
Abstract:
In this work, we present a catalog of cataclysmic variables (CVs)
identified from the sixth data release (DR6) of the Large Sky Area
Multi-Object Fiber Spectroscopic Telescope (LAMOST). To single out the
CV spectra, we introduce a novel machine-learning algorithm called
UMAP to screen out a total of 169509 Hα emission spectra, and
obtain a classification accuracy of the algorithm of over 99.6% from
the cross-validation set. We then apply the template-matching program
PyHammer v2.0 to the LAMOST spectra to obtain the optimal spectral
type with metallicity, which help us identify the chromospherically
active stars and potential binary stars from the 169509 spectra. After
visually inspecting all of the spectra, we identify 323 CV candidates
from the LAMOST database, among them 52 objects are new. We further
classify the new CV candidates in subtypes based on their spectral
features, including five DN subtypes during outbursts, five NL
subtypes, and four magnetic CVs (three AM Her type and one IP type).
We also find two CVs that have been previously identified by
photometry and confirm their previous classification with the LAMOST
spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 109 21 New confirmed CVs from LAMOST DR6
table2.dat 109 70 New possible CV candidates from LAMOST DR6
table3.dat 109 415 Previously known CV candidates from LAMOST DR6
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See also:
B/cb : Cataclysmic Binaries, LMXBs, and related objects (Ritter+, 2004)
V/94 : Catalog and Atlas of Cataclysmic Variables (Downes+ 1997)
V/110 : Catalog of Cataclysmic Variables (Downes+ 2001)
V/113 : Cataclysmic Binaries, LMXBs, and related objects (Ritter+, 2003)
V/123 : Catalog of Cataclysmic Variables (Downes+ 2001-2006)
V/153 : LAMOST DR4 catalogs (Luo+, 2018)
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
J/AJ/142/181 : CVs from SDSS. VIII. The final year (Szkody+, 2011)
J/AJ/146/34 : IR photometry of DA white dwarfs from LAMOST (Zhang+, 2013)
J/MNRAS/443/3174 : 72 faint CV candidates in CRTS (Breedt+, 2014)
J/MNRAS/456/4441 : Outburst cat. of cataclysmic variables (Coppejans+, 2016)
J/other/RAA/18.68 : Cataclysmic variables from LAMOST DR3 (Han+, 2018)
J/AJ/159/43 : Sp. identified CVs from LAMOST survey. I. (Hou+, 2020)
J/AJ/159/198 : CVs in the ZTF 1st-yr (2018-2019) (Szkody+, 2020)
J/AJ/160/151 : RVs of 5 cataclysmic variable cand. (Thorstensen, 2020)
Byte-by-byte Description of file: table[123].dat
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Bytes Format Units Label Explanations
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1 A1 --- f_obsid [*n] Flag on object (1)
3- 11 I9 --- obsid [312121/663709117] LAMOST Observation ID
13- 31 A19 --- LAMOST LAMOST position-based designation
33- 37 I5 d MJD [55858/58252] Modified Julian Date of
observation (JD-2400000.5)
39- 49 F11.7 deg RAdeg Right Ascension (J2000)
51- 60 F10.7 deg DEdeg Declination (J2000)
62 A1 --- n_sType1 [*] *=spectrum of a new CV candidate
63- 72 A10 --- sType1 CV subtype, this work (2)
74- 85 A12 --- sType2 CV subtype, Hou+ (2020, J/AJ/159/43) (3)
87- 91 A5 --- sType3 CV subtype, SIMBAD (4)
93-101 F9.5 mag ZTFmag [12.4/20.9]? Median ZTF magnitude (5)
103-109 F7.5 mag dZTFmag [0.03/6.1]? Magnitude difference (6)
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Note (1): Flag as follows:
* = Spectrum no longer present in DR6 v2
n = Two poorly known objects discussed in section 5.2.
Note (2): If a source has more than one spectrum but the spectrum has no
visible CV characteristics, we leave the row blank.
For new confirmed CV candidates, we particularly give the
subtype inferred from the spectrum (DN=dwarf nova; NL=nova-like variable;
polar (or AM Her type); intermediate polar (IP)).
Note (3): The column is the CV subtype for the corresponding LAMOST DR6
spectra given by Hou+ (2020, J/AJ/159/43).
Note (4): The column is the CV subtype from SIMBAD, or from the literature
subtype given in the catalogue of Hou+ (2020, J/AJ/159/43).
If the source exists in SIMBAD but is given a type other than CV,
it is marked as "none".
Note (5): Median magnitude taken from the ZTF DR4. The ZTF data is obtained
by best matching within 2 arcsec with our result
Note (6): The difference between the maximum and minimum magnitude taken from
the ZTF DR4.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 11-Apr-2022