Searching for giga-Jansky fast radio bursts from the Milky Way with a global array of low-cost radio receivers

Dan Maoz,Abraham Loeb

doi:10.1093/mnras/stx400

Abstract

If fast radio bursts (FRBs) originate from galaxies at cosmological distances, then their all-sky rate implies that the Milky Way may host an FRB on average once every 30-1500 years. If FRBs repeat for decades or centuies, a local FRB could be active now. A typical Galactic FRB would produce a millisecond radio pulse with ~1 GHz flux density of ~3E10 Jy, comparable to the radio flux levels and frequencies of cellular communication devices (cell phones, Wi-Fi, GPS). We propose to search for Galactic FRBs using a global array of low-cost radio receivers. One possibility is to use the ~1GHz communication channel in cellular phones through a Citizens-Science downloadable application. Participating phones would continuously listen for and record candidate FRBs and would periodically upload information to a central data processing website, which correlates the incoming data from all participants, to identify the signature of a real, globe-encompassing, FRB from an astronomical distance. Triangulation of the GPS-based pulse arrival times reported from different locations will provide the FRB sky position, potentially to arc-second accuracy. Pulse arrival times from phones operating at diverse frequencies, or from an on-device de-dispersion search, will yield the dispersion measure (DM) which will indicate the FRB source distance within the Galaxy. A variant of this approach would be to use the built-in ~100 MHz FM-radio receivers present in cell phones for an FRB search at lower frequencies. Alternatively, numerous "software-defined radio" (SDR) devices, costing ~$10 US each, could be plugged into USB ports of personal computers around the world (particularly in radio quiet regions) to establish the global network of receivers.

Highlights

The origin and nature of fast radio bursts (FRBs) have remained enigmatic since the first FRB discovery by Lorimer et al (2007)
FRBs are selected to have large measured dispersion measure (DM) of ∼ 300 − 1600 pc cm−3, in excess of the values expected from models of the interstellar electron distribution in the Milky Way galaxy, and have been inferred to originate from extragalactic sources at cosmological distances
The cosmological distance has been confirmed in the case of the sole repeating FRB 121102, which has been localised to a dwarf galaxy at redshift z = 0.19 (Chatterjee et al 2017; Tendulkar et al 2017; Marcote et al 2017)

Summary

INTRODUCTION

The origin and nature of fast radio bursts (FRBs) have remained enigmatic since the first FRB discovery by Lorimer et al (2007). By binning an incoming signal into millisecond (∆t = 10−3 s) time bins a W√i-Fi receiver would improve its sensitivity in proportion to ∆t, i.e. by a factor of ∼ 200, to a level of fν ∼ 5 × 10−17 W m−2Hz−1 (5 × 109 Jy, i.e. 5 GJy). This is a factor 6 fainter than the typical Galactic FRB flux discussed above, and means that such a Galactic FRB, and even fainter and perhaps-more-frequent FRBs, would be detectable by existing communication devices.

A GLOBAL ARRAY OF CELLULAR RECEIVERS FOR GALACTIC FRB DETECTION

A cell phone communications channel approach

A cell phone FM radio channel approach

A software-defined radio approach

CONCLUSIONS