The CHIME Fast Radio Burst Project: System Overview

Abstract

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a novel transit radio telescope operating across the 400–800 MHz band. CHIME is composed of four 20 m × 100 m semicylindrical paraboloid reflectors, each of which has 256 dual-polarization feeds suspended along its axis, giving it a ≳200 deg2 field of view. This, combined with wide bandwidth, high sensitivity, and a powerful correlator, makes CHIME an excellent instrument for the detection of fast radio bursts (FRBs). The CHIME Fast Radio Burst Project (CHIME/FRB) will search beam-formed, high time and frequency resolution data in real time for FRBs in the CHIME field of view. Here we describe the CHIME/FRB back end, including the real-time FRB search and detection software pipeline, as well as the planned offline analyses. We estimate a CHIME/FRB detection rate of 2–42 FRBs sky–1 day–1 normalizing to the rate estimated at 1.4 GHz by Vander Wiel et al. Likely science outcomes of CHIME/FRB are also discussed. CHIME/FRB is currently operational in a commissioning phase, with science operations expected to commence in the latter half of 2018.

The Northern Cross fast radio burst project – I. Overview and pilot observations at 408 MHz

“…the ratio between a given rate and the ideal rate -i.e., the rate 2 S ν ∝ ν −β , where S ν is the flux density at the frequency ν. unaffected by intra-channel smearing. We note that FRBs have a noticeable spectral modulation at low frequencies (CHIME/FRB Collaboration et al 2018Collaboration et al , 2019a, however, this effect is less prominent for the relatively narrow band of our observations, compared to wider bandwidth instruments. We expect a significant loss of events due to intra-channel smearing for the survey I, with a magnitude that depends upon the chosen FRB model.…”

“…Initially, FRBs were detected at GHz frequencies (Lorimer et al 2007; Thornton et al 2013;Spitler et al 2014;Burke-Spolaor & Bannister 2014;Petroff et al 2015;Bhandari et al 2018;Patel et al 2018;Shannon et al 2018), but recent observations in the 400 − 800 MHz range have enormously increased the FRB statistics (e.g., Caleb et al 2016;CHIME/FRB Collaboration et al 2018, 2019a and placed increasingly better upper limits on their event rate In the foreground, the Northern Cross with its two orthogonal arms. (Sokolowski et al 2018;Sanidas et al 2019;ter Veen et al 2019), showing the advantage of large field of view (FoV) observations.…”

On the FRB luminosity function – – II. Event rate density

“…The FRB detection rate as a function of minimum detection flux and field of view is given in Figure 4. Ob- viously, telescopes with high gain and large field of view are the best for FRB searching, e.g.m CHIME and Tian-Lai (CHIME/FRB Collaboration et al 2018;Chen 2012). Thanks to 13 beams receiver (Staveley-Smith et al 1996), the Parkes 64-m radio telescope has played a pioneering role in FRB searching ever since its serendipitous discovery of the "Lorimer Burst" (Lorimer et al 2007).…”

“…The situation changed dramatically in recent years, thanks to the deployment of telescope arrays with large fields of view (FoV), e.g. ASKAP with FoV = 160 deg 2 (Bannister et al 2017) and CHIME with FoV > 200 deg 2 (CHIME/FRB Collaboration et al 2018). Those new facilities have greatly boosted the annual detection rate of FRBs.…”

Limits on absorption from a 332-MHz survey for fast radio bursts

“…Since their discovery in 2007 (Lorimer et al 2007), more than 64 have been published (see e.g. Thornton et al 2013;Champion et al 2016;CHIME/FRB Collaboration et al 2018;Shannon et al 2018). The first FRB seen to repeat was FRB 121102 , leading to its localisation and the identification of the host Chatterjee et al 2017).…”