Optical Light Curve of 4FGL J0935.3+0901: A Flaring Black Widow Candidate
Abstract
I obtained time-series photometry of the compact binary candidate for the Fermi source 4FGL J0935.3+0901. Superposed on the 2.44 hr orbital modulation are day-to-day variations and frequent flaring as seen in several redback and black widow millisecond pulsars (MSPs). The short orbital period favors a black widow. While the modulation of ≤1 mag is smaller than that of most black widows, it could indicate a low orbital inclination. Although a published optical spectrum shows strong emission lines, the light curve evinces pulsar heating of the companion star rather than accretion-disk emission of a transitional MSP. Emission lines and flaring occur in the same objects, probably powered by shocks between the relativistic pulsar wind and a wind driven off the companion star. I also recovered the period in photometry from the Zwicky Transient Facility (ZTF). A phase-connected ephemeris derived from MDM Observatory and ZTF data spanning 4 yr yields a period of 0.10153276(36) days and an epoch for the ascending node of the putative pulsar.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2022
- DOI:
- 10.3847/2041-8213/ac746f
- arXiv:
- arXiv:2205.14786
- Bibcode:
- 2022ApJ...932L...8H
- Keywords:
-
- Gamma-ray sources;
- Millisecond pulsars;
- 633;
- 1062;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 8 pages, 3 figures, corrected references, published in ApJ Letters