Periodic activity from a fast radio burst source

Abstract

Fast radio bursts (FRBs) are bright, millisecond-duration radio transients originating from extragalactic distances 1 . Their origin is unknown. Some FRB sources emit repeat bursts, ruling out cataclysmic origins for those events [2][3][4] . Despite searches for periodicity in repeat burst arrival times on time scales from milliseconds to many days 2, 5-7 , these bursts have hitherto been observed to appear sporadically, and though clustered 8 , without a regular pattern. Here we report the detection of a 16.35 ± 0.18 day periodicity from a repeating FRB 180916.J0158+65 detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project (CHIME/FRB) 4, 9 . In 28 bursts recorded from 16th September 2018 through 30th October 2019, we find that bursts arrive in a 4.0-day phase window, with some cycles showing no bursts, and some showing multiple bursts, within CHIME's limited daily exposure. Our results suggest a mechanism for periodic modulation either of the burst emission itself, or through external amplification or absorption, and disfavour models invoking purely sporadic processes.Last year the CHIME/FRB collaboration reported the discovery of eight new repeating FRB sources 4 , including FRB 180916.J0158+65, which was recently localized to a star-forming region in a nearby massive spiral galaxy at redshift 0.0337±0.0002 10 . From September 2018 to November 2019, CHIME/FRB has detected a total of 28 bursts from FRB 180916.J0158+65, which remains the most active source from this recent CHIME/FRB repeater sample. The barycentric arrival times for the 28 bursts (including those has been published before) from FRB 180916.J0158+65, corrected for delays from pulse dispersion, are listed in Extended Data Table 1.To search for periodicity, the burst arrival times (spanning a 400-day time range) were folded with different periods from 1.57 to 62.8 days (see Methods), with a Pearson's χ 2 test applied to each resulting profile with 8 phase bins 11 . A reduced χ 2 1 with respect to a uniform distribution indicates a periodicity unlikely to arise by chance. Furthermore, to account for the possible non-Poissonian statistics of the bursts 12 , we have applied the search with different weighting schemes that consider clustered bursts of different time range to be correlated events (see Methods).Searches with different weightings return periodograms of similar shape and have the same primary peak with significance varying between 3.5 − 8σ. As an example, the reduced χ 2 versus period using a weighting that counts only active days instead of individual events is shown in Figure 1a. A distinct peak is detected at 16.35 ± 0.18 days, with

First Discovery of a Fast Radio Burst at 350 MHz by the GBNCC Survey

“…A particularly interesting discovery reported by the CHIME/ FRB Collaboration is the repeating source FRB 180916. J0158+65, which shows a 16.35 day modulation in its burst activity (CHIME/FRB Collaboration et al 2020). In Spring 2020, follow-up observations of FRB 180916.J0158+65 in the 300−400 MHz frequency range (Chawla et al 2020;Pilia et al 2020) provided the lowest-frequency detections of FRBs to date.…”

Implications of a Fast Radio Burst from a Galactic Magnetar

“…The recurrent FRB 180916 was recently shown by the CHIME/ FRB collaboration to exhibit a 16 day period of unknown origin (CHIME/FRB Collaboration et al 2020a). Again, although known Galactic magnetars offer no clear explanation for periodic behavior at this scale (with the possible exception of candidate magnetar 1E 1613485055, which has a measured period of 6.7 hr; de Luca et al 2006), reasonable variations in the properties of extragalactic magnetars (e.g., extremely slow rotation, precession, or presence in a binary) offer a potential explanation (Beniamini et al 2020;Levin et al 2020;Lyutikov et al 2020;Tong et al 2020;Yang & Zou 2020;Zanazzi & Lai 2020).…”

“…(yellow; Law et al 2017; Gourdji et al 2019), the recently localized CHIME repeater FRB180916 (purple; Marcote et al 2020; CHIME/FRB Collaboration et al 2020a), and the apparently nonrepeating FRBs180924 (green, upper limits denoted by upside-down triangles; Bannister et al 2019), 190523 (brown; Ravi 2019), and 181112 (blue;Prochaska et al 2019). We have used quoted rates where possible(Law et al 2017;Gourdji et al 2019;CHIME/FRB Collaboration et al 2020a) and otherwise estimated Poissonian rates based on quoted field exposure times where available.…”

Multiwavelength Radio Observations of Two Repeating Fast Radio Burst Sources: FRB 121102 and FRB 180916.J0158+65

“…Over the past few years, daily radio observations of the northern hemisphere sky in the 400-800 MHz frequency band with the Canadian Hydrogen Intensity Mapping Experi-ment(CHIME) transit radio telescope have led to discovery of many new repeatingFRB sources (The CHIME/FRB Collaboration et al 2019aFonseca et al 2020), enabled by the instrument's large instantaneous field of view(FoV), wide bandwidth, and high sensitivity (The CHIME/FRB Collaboration et al 2018). In particular, the discovery of FRB180916.J0158+65(also referred to as FRB 20180916B; The CHIME/FRB Collaboration et al 2019b), its subsequent localization to a nearby massive spiral galaxy (Marcote et al 2020), and the detection of a 16.35 day periodicity (or possibly a higher frequency alias of this period) in the burst arrival times (The CHIME/FRB Collaboration et al 2020a) have facilitated detailed studies of the source via follow-up observations across multiple wavelengths(e.g., see Scholz et al 2020;Tendulkar et al 2020). Most bursts from FRB180916.J0158+65 have been detected within a ∼5.4 day interval during cycles when the source was observed to be active (e.g., see Chawla et al 2020;Marthi et al 2020;Pilia et al 2020;Sand et al 2020;The CHIME/FRB Collaboration et al 2020a), but some bursts have been found to occur slightly outside this activity window (e.g., see Aggarwal & Realfast Collaboration 2020).…”