Search for DA White Dwarf Binary Candidates from LAMOST DR7

Autor: Hua-Hui Yan, Jing-Kun Zhao, Wei-Bin Shi, Jin-Cheng Guo, Liang Wang, Zhen-Xin Lei, Gang Zhao
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Universe, Vol 9, Iss 4, p 177 (2023)
Druh dokumentu: article
ISSN: 2218-1997
DOI: 10.3390/universe9040177
Popis: We obtained spectroscopy data for 761 Degenerate A (DA)white dwarfs (WDs) with multiple LAMOST observations. The radial velocity (RV) of each spectrum was calculated using the cross-correlation function method (CCF), and 60 DA WD binary candidates were selected based on the variation of the RV. Then, the atmosphere parameter Teff, logg, and the mass of these DA WDs were estimated by the Balmer line fitting method and interpolation in theoretical evolution tracks, respectively. Our parameters are consistent with those from SDSS and Gaia for the common stars. No evident difference in the mass distribution of binary candidates compared with total DA WDs was found. We surmise these DA WD binary candidates are mainly composed of two WDs. With the Zwicky Transient Facility (ZTF) data, we obtained the light curve periods of two targets with significant light curve periods in the DA WD binary candidates. For the spectra with anomalous CCF curves or with large errors in their RV calculations, we re-certified their spectral types by visual review. Based on their spectral features, we found 11 DA + M-type binaries and four cataclysmic variables (CVs). The light curve period of one CV was obtained with ZTF data.
Databáze: Directory of Open Access Journals
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