Constraints on the low frequency spectrum of FRB 121102

Abstract

While repeating fast radio bursts (FRBs) remain scarce in number, they provide a unique opportunity for follow-up observations that enhance our knowledge of their sources and potentially of the FRB population as a whole. Attaining more burst spectra could lead to a better understanding of the origin of these bright, millisecond-duration radio pulses. We therefore performed $\sim$20 hr of simultaneous observations on FRB 121102 with the Effelsberg 100-m radio telescope and the Low Frequency Array (LOFAR) to constrain the spectral behaviour of bursts from FRB 121102 at 1.4 GHz and 150 MHz. This campaign resulted in the detection of nine new bursts at 1.4 GHz but no simultaneous detections with LOFAR. Assuming that the ratio of the fluence at two frequencies scales as a power law, we placed a lower limit of $\alpha$ > -1.2 $\pm$ 0.4 on the spectral index for the fluence of the instantaneous broad band emission of FRB 121102. For the derivation of this limit, a realistic fluence detection threshold for LOFAR was determined empirically assuming a burst would be scattered as predicted by the NE2001 model. A significant variation was observed in the burst repeat rate R at L-band. During observations in September 2016, nine bursts were detected, giving R = 1.1 $\pm$ 0.4 hr${}^{-1}$, while in November no bursts were detected, yielding R < 0.3 hr${}^{-1}$ (95% confidence limit). This variation is consistent with earlier seen episodic emission of FRB 121102. In a blind and targeted search, no bursts were found with LOFAR at 150 MHz, resulting in a repeat rate limit of R < 0.16 hr${}^{-1}$ (95% confidence limit). Burst repeat rate ratios of FRB 121102 at 3, 2, 1.4, and 0.15 GHz are consistent within the uncertainties with a flattening of its spectrum below 1 GHz.

8 pages, 2 tables, 1 figure

References in corpus (8)

• The direct localization of a fast radio burst and its host
• The Host Galaxy and Redshift of the Repeating Fast Radio Burst FRB 121102
• Fast Radio Burst Discovered in the Arecibo Pulsar ALFA Survey
• The Repeating Fast Radio Burst FRB 121102 as Seen on Milliarcsecond Angular Scales
• A Second Source of Repeating Fast Radio Bursts
• A Multi-telescope Campaign on FRB 121102: Implications for the FRB Population
• FRB 121102 is coincident with a star forming region in its host galaxy
• A search for optical bursts from the repeating fast radio burst FRB 121102

Cited by in corpus (34)

• Possible periodic activity in the repeating FRB 121102
• Observational Evidence for Primordial Black Holes: A Positivist Perspective
• Repeating behaviour of FRB 121102: periodicity, waiting times and energy distribution
• LOFAR Detection of 110-188 MHz Emission and Frequency-Dependent Activity from FRB 20180916B
• A sample of low energy bursts from FRB 121102
• The Physics of Fast Radio Bursts
• Chromatic periodic activity down to 120 MHz in a Fast Radio Burst
• Extremely band-limited repetition from a fast radio burst source
• Detection of Repeating FRB 180916.J0158+65 Down to Frequencies of 300 MHz
• The lowest frequency Fast Radio Bursts: Sardinia Radio Telescope detection of the periodic FRB 180916 at 328 MHz
• The FRB 20121102A November rain in 2018 observed with the Arecibo Telescope
• Comprehensive analysis of a dense sample of FRB 121102 bursts
• An accreting stellar binary model for active periodic fast radio bursts
• A Dual-band Radio Observation of FRB 121102 with the Deep Space Network and the Detection of Multiple Bursts
• Multiwavelength Radio Observations of Two Repeating Fast Radio Burst Sources: FRB 121102 and FRB 180916.J0158+65
• High frequency study of FRB 20180916B using the 100-m Effelsberg radio telescope
• Burst timescales and luminosities link young pulsars and fast radio bursts
• Multiband Detection of Repeating FRB 20180916B
• Can Primordial Black Holes as all Dark Matter explain Fast Radio Bursts?
• Limits on Simultaneous and Delayed Optical Emission from Well-localized Fast Radio Bursts
• Murchison Widefield Array rapid-response observations of the short GRB 180805A
• The Apertif Radio Transient System (ARTS): Design, Commissioning, Data Release, and Detection of the first 5 Fast Radio Bursts
• The Northern Cross Fast Radio Burst project IV. Multi-wavelength study of the actively repeating FRB 20220912A
• FRB 20121102A monitoring: Updated periodicity in the L band
• Constraining Near-Simultaneous Radio Emission from Short Gamma-ray Bursts using CHIME/FRB
• Comparative Analysis of the Observational Properties of Fast Radio Bursts at the Frequencies of 111 and 1400 MHz
• Confining Burst Energy Function and Spectral Fringe Pattern of FRB 20121102A with Multifrequency Observations
• Modelling the energy distribution in CHIME/FRB Catalog-1
• The Low Frequency Perspective on Fast Radio Bursts
• A maximum likelihood estimate of the parameters of the FRB population
• A targeted search for repeating fast radio bursts with the MWA
• Diverse origins for non-repeating fast radio bursts: Rotational radio transient sources and cosmological compact binary merger remnants
• Constraining the Fast Radio Burst (FRB) properties using the joint distributions of dispersion measure and fluence of the events detected at Parkes, ASKAP, CHIME and UTMOST
• The Northern High Time Resolution Universe pulsar survey: II. Single-pulse search set-up and simulations