J/A+A/656/A125 ACV variables in the Zwicky Transient Facility (Faltova+, 2021)
A case study of ACV variables discovered in the Zwicky Transient Facility
survey.
Faltova N., Kallova N., Prisegen M., Stanek P., Supikova J., Xia C.,
Bernhard K., Hummerich S., Paunzen E.
<Astron. Astrophys. 656, A125 (2021)>
=2021A&A...656A.125F 2021A&A...656A.125F (SIMBAD/NED BibCode)
ADC_Keywords: Stars, Ap ; Stars, peculiar ; Stars, variable ; Spectral types ;
MK spectral classification
Keywords: stars: chemically peculiar - stars: variable: general -
stars: rotation - binaries: eclipsing
Abstract:
The present work presents a case study of known variables from the
Zwicky Transient Facility (ZTF) survey, with the aim of investigating
the survey's suitability for the detection and study of new ACV
variables. Using suitable selection criteria based on the known
characteristics of ACV variables, candidate ACV stars were selected
from the ZTF Catalog of Periodic Variable Stars. All light curves were
inspected in detail to select the most promising candidates. Where
available, low-resolution spectra from the Large Sky Area Multi-Object
Fiber Spectroscopic Telescope (LAMOST) were employed to classify the
stars on the MK system and confirm their status as mCP stars. We have
identified 86 new promising ACV star candidates. 15 of these stars
have LAMOST spectra available, which, in all cases, confirm them as
classical mCP stars, which highlights the viability of our approach.
We present astrophysical parameters for all sample stars, which can be
sorted into four subgroups characterized by distinct light curve
shapes. Anti-phase variations in different photometric passbands, in
particular, is a unique characteristic of a subset of ACV stars
readily usable for their identification. The availability of data in
three different passbands (g, r, and i) is a major advantage of the
ZTF survey. On the basis of our experience with other photometric
surveys and the analysis of light curves, we conclude that the ZTF is
well suited for the search for, and the analysis of, ACV variables,
which, however, are not considered in the available ZTF variable star
catalogues. Further work will be concerned with the development and
refinement of a search algorithm to correctly identify these stars in
ZTF data and, subsequently, in massive photometric time-series
databases in general.
Description:
We here present the MK spectral types for the 15 sample stars with
spectra in LAMOST DR7. Also provided are the LAMOST observation ID
(ObsID), the signal-to-noise ratio in the g band (S/Ng), and the
original LAMOST spectra.
In the spectral types, parentheses and colons denote, respectively,
that the corresponding peculiarity is only weakly present or doubtful.
More information on the spectral classification process is provided in
Section 3.1 of the source paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 102 15 Spectral types of the 15 sample stars with
spectra in LAMOST DR7
sp/* . 15 Individual fits spectrum files
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See also:
http://dr7.lamost.org/ : LAMOST DR7 Home Page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/15] Running number
4- 22 A19 --- LAMOST LAMOST identifier (JHHMMSS.ss+DDMMSS.s)
24- 32 I9 --- ObsID LAMOST observation ID
34- 36 I3 --- S/Ng Sloan g band S/N of analysed spectrum
38- 58 A21 --- SpType Spectral type as derived in this study
60-102 A43 --- FileName LAMOST FITS spectrum FileName in
subdirectory sp
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Acknowledgements:
Ernst Paunzen, epaunzen(at)physics.muni.cz
(End) E. Paunzen [Masaryk Univ., Czech Republic], P. Vannier [CDS] 06-Dec-2021