We report on the discovery of a promising candidate for a black widow (BW) millisecond pulsar binary, 4FGL J0336.0+7502, which shows many pulsar-like properties in the 4FGL-DR2 catalog. Within the 95% error region of the LAT source, we identified an optical counterpart with a clear periodicity at P _orb = 3.718178(9) hr using the Bohyunsan 1.8 m Telescope, the Lulin One-meter Telescope, the Canada–France–Hawaii Telescope, and Gemini-North. At the optical position, an X-ray source was marginally detected in the Swift/X-Ray Telescope archival data, and the detection was confirmed by our Chandra/ACIS DDT observation. The spectrum of the X-ray source can be described by a power-law model of Γ _x = 1.6 0.7 and erg cm⁻² s⁻¹. The X-ray photon index and the low X-ray-to-γ-ray flux ratio (i.e., <1%) are both consistent with that of many known BW pulsars. There is also a hint of an X-ray orbital modulation in the Chandra data, although the significance is very low (1.3σ). If the pulsar identity and the X-ray modulation are confirmed, it would be the fifth BW millisecond pulsar binary that showed an orbitally modulated emission in X-rays.

我们报告发现了黑寡妇 (BW) 毫秒脉冲星双星的有希望候选者 4FGL J0336.0+7502，它在 4FGL-DR2 目录中显示了许多类似脉冲星的特性。在 LAT 源的 95% 误差区域内，我们使用 Bohyunsan 1.8 m 望远镜、Lulin 一米望远镜、加拿大-法国-夏威夷望远镜确定了一个在P _orb = 3.718178(9) hr处具有明显周期性的光学对应物，和双子座北。在光学位置，在 Swift/X 射线望远镜档案数据中勉强检测到 X 射线源，我们的 Chandra/ACIS DDT 观测证实了这一发现。X 射线源的光谱可以用 Γ _x = 1.6 0.7 和erg cm ^-2 s ^-1的幂律模型来描述 . X 射线光子指数和低 X 射线与γ射线通量比（即 <1%）都与许多已知的 BW 脉冲星一致。Chandra 数据中也有 X 射线轨道调制的暗示，尽管重要性非常低（1.3 σ）。如果脉冲星的身份和 X 射线调制得到确认，这将是第五颗 BW 毫秒脉冲星双星，它在 X 射线中显示出轨道调制发射。