Search for carbon stars and DZ white dwarfs in SDSS spectra survey through machine learning

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 9,374 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.

5 figures, 6 tables

References in corpus (5)

• SDSS DR7 White Dwarf Catalog
• On the Spectral Evolution of Cool, Helium-Atmosphere White Dwarfs: Detailed Spectroscopic and Photometric Analysis of DZ Stars
• Innocent Bystanders: Carbon Stars from the Sloan Digital Sky Survey
• Principal Component Analysis of SDSS Stellar Spectra
• Extension of the C star rotation curve of the Milky Way to 24 kpc

Cited by in corpus (14)

• New white dwarf stars in the Sloan Digital Sky Survey Data Release 10
• Overview of the LAMOST survey in the first decade
• Carbon stars identified from LAMOST DR4 using Machine Learning
• Carbon stars from LAMOST DR2 data
• Classifying Single Stars and Spectroscopic Binaries Using Optical Stellar Templates
• The Time-Domain Spectroscopic Survey: Target Selection for Repeat Spectroscopy
• Evidence for Halo Kinematics among Cool Carbon-Rich Dwarfs
• An Efficient Method for Rare Spectra Retrieval in Astronomical Databases
• Unexpected Short-Period Variability in Dwarf Carbon Stars from the Zwicky Transient Facility
• The Binary Dwarf Carbon Star SDSS J125017.90+252427.6
• The Time-Domain Spectroscopic Survey: Radial Velocity Variability in Dwarf Carbon Stars
• A Chandra Study: Are Dwarf Carbon Stars Spun Up and Rejuvenated by Mass Transfer?
• Deep learning interpretability analysis for carbon star identification in Gaia DR3
• New Clues to the Evolution of Dwarf Carbon Stars From Their Variability and X-ray Emission