GECAM Detection of a Bright Type I X-Ray Burst from 4U 0614+09: Hint for Its Spin Frequency at 413 Hz

One month after launching the Gravitational Wave High-energy Electromagnetic Counterpart All-sky Monitor, a bright thermonuclear X-ray burst from 4U 0614+09 was observed on 2021 January 24. We report the time-resolved spectroscopy of the burst and a hint of burst oscillation at 413 Hz with a fractional amplitude similar to 2.0% (rms). This coincides with the burst oscillation previously discovered with Swift/Burst Alert Telescope (Strohmayer et al. 2008), and therefore supports the spin frequency of this source. This burst is a bright one in the normal bursts detected from 4U 0614+09, which leads to an upper limit of distance estimation of 3.1 kpc. The folded light curve during the burst oscillation shows a sinusoidal structure, which is consistent with previous observations.

Automated summary

The translated text describes a bright thermonuclear X-ray burst observed from 4U 0614+09, including information about the time-resolved spectroscopy of the burst and the presence of burst oscillation. The findings support the spin frequency of the source and found consistent results with previous observations.