Possible periodic activity in the repeating FRB 121102. Issue 4 (19th May 2020)

• Record Type: Journal Article
• Authors: Rajwade, K M; Mickaliger, M B; Stappers, B W; Morello, V; Agarwal, D; Bassa, C G; Breton, R P; Caleb, M; Karastergiou, A; Keane, E F; Lorimer, D R
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 495:Issue 4(2020)
• Page Start: 3551
• Page End: 3558
• Publication Date: 2020-05-19
• Subjects: surveys -- binaries: general -- radio continuum: transients; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa1237
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: The discovery that at least some Fast Radio Bursts (FRBs) repeat has ruled out cataclysmic events as the progenitors of these particular bursts. FRB 121102 is the most well-studied repeating FRB but despite extensive monitoring of the source, no underlying pattern in the repetition has previously been identified. Here, we present the results from a radio monitoring campaign of FRB 121102 using the 76 m Lovell telescope. Using the pulses detected in the Lovell data along with pulses from the literature, we report a detection of periodic behaviour of the source over the span of 5 yr of data. We predict that the source is currently 'off' and that it should turn 'on' for the approximate MJD range 59002−59089 (2020 June 2 to 2020 August 28). This result, along with the recent detection of periodicity from another repeating FRB, highlights the need for long-term monitoring of repeating FRBs at a high cadence. Using simulations, we show that one needs at least 100 h of telescope time to follow-up repeating FRBs at a cadence of 0.5–3 d to detect periodicities in the range of 10–150 d. If the period is real, it shows that repeating FRBs can have a large range in their activity periods that might be difficult to reconcile with neutron star precession models.