Possible Periodic Activity in the Short Bursts of SGR 1806-20: Connection to Fast Radio Bursts

Magnetars are highly magnetized neutron stars that are characterized by recurrent emission of short-duration bursts in soft gamma-rays/hard X-rays. Recently, FRB 200428 was found to be associated with an X-ray burst from a Galactic magnetar. Two fast radio bursts show mysterious periodic activity. However, it is unclear whether magnetar X-ray bursts are periodic phenomena. In this paper, we investigate the activity period of SGR 1806-20. More than 3000 short bursts observed by different telescopes are collected, including the observations of RXTE, HETE-2, ICE, and Konus. We consider the observation windows and divide the data into two subsamples to alleviate the effect of uneven sampling. The epoch-folding and Lomb-Scargle methods are used to derive the period of the short bursts. We find a possible period of about 398.20 25.45 days, but other peaks exist in the periodograms. If the period is real, the connection between short bursts of magnetars and fast radio bursts should be investigated extensively.

Automated summary

The study investigated the activity period of the magnetar SGR 1806-20 and found a possible period of around 398.20±25.45 days, with other peaks also present. Further research is needed to explore the connection between short bursts of magnetars and fast radio bursts.