A Systematic Search for Redback and Black Widow Candidates Based on the 4FGL-DR3 Unassociated Sources and the Zwicky Transient Facility Data

• Published in: The Astrophysical journal Vol. 978; no. 1; pp. 106 - 131
• Main Authors: Lu, Chunyan, Ren, Liangliang, Lin, Jiamao, Huang, Wenjun, Yang, Hewen, Tam, P. H. Thomas
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 01.01.2025; IOP Publishing
• Subjects: Algorithms; Binary pulsars; Binary stars; Companion stars; Data processing; Ellipsoidal variable stars; Gamma ray sources; Gamma rays; Hertzsprung-Russell diagram; Irradiation; Millisecond pulsars; Pulsars; Spectroscopy; Stellar evolution; Stellar system evolution; Time domain analysis; Transients (astronomy); Variability; Wavelengths
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.3847/1538-4357/ad8e39

Spider pulsars represent a unique subclass of radio millisecond pulsars in binaries, and are further categorized into black widows and redbacks according to the mass of the low-mass companion. These pulsars, observable across multiple wavelengths, exhibit periodic variability in optical. The discovery and study of additional spider-type pulsars are crucial for a fuller understanding the evolution of binary stars in close orbits and the recycling theory of millisecond pulsars. In this work, we systematically searched for spider pulsar binary systems using time-domain variability data from the Zwicky Transient Facility and unassociated gamma-ray sources from the Fermi 4FGL-DR3 catalog. We developed a time-domain data processing pipeline that employs the Lomb–Scargle periodogram algorithm. As a result, we identified a total of 194 ellipsoidal variables and irradiation-type binary stars. Further refinement using the Gaia Hertzsprung–Russell diagram resulted in a selection of 24 spider pulsar candidates. Incorporating the 4FGL 95% confidence error ellipse reduced the sample to 19 candidates. An additional filter using the Gaia color-reduced proper motion diagram yielded nine “gold sample” candidates. These newly identified spider pulsar candidates will guide future observational campaigns in radio, X-ray, and optical spectroscopy, aiding in the comprehensive validation of their nature.