Galactic Radio Explorer: An All-sky Monitor for Bright Radio Bursts

Abstract

We present the Galactic Radio Explorer (GReX), an all-sky monitor to probe the brightest bursts in the radio sky. Building on the success of STARE2, we will search for fast radio bursts (FRBs) emitted from Galactic magnetars as well as bursts from nearby galaxies. GReX will search down to ∼ ten microseconds time resolution, allowing us to find new super giant radio pulses from Milky Way pulsars and study their broadband emission. The proposed instrument will employ ultra-wide band (0.7-2 GHz) feeds coupled to a high performance (receiver temperature < 10 K) low noise amplifier (LNA) originally developed for the DSA-110 and DSA-2000 projects. In GReX Phase I (GReX-I), unit systems will be deployed at Owens Valley Radio Observatory (OVRO), NASA's Goldstone station, and at Telescope Array, Delta Utah. Phase II will expand the array, placing feeds in India, Australia, and elsewhere in order to build up to continuous coverage of nearly 4π steradians and to increase our exposure to the Galactic plane. We model the local magnetar population to forecast for GReX, finding the improved sensitivity and increased exposure to the Galactic plane could lead to dozens of FRB-like bursts per year.

BURSTT: Bustling Universe Radio Survey Telescope for Taiwan

“…To achieve a complete census of FRBs, monitoring observations with a very wide FoV is essential (Bochenek et al 2020a;Connor et al 2021). If the FoV covers only a small part of the sky, FRBs can be easily missed because most occur outside the FoV.…”

“…Figure 1 shows the FoV versus the SEFD and the effective area for the existing, planned, and future-concept FRB surveys, including CHIME (CHIME/FRB Collaboration et al 2018), Australian Square Kilometre Array Pathfinder (ASKAP) 1 , the Canadian Hydrogen Observatory and Radio-transient Detector (CHORD) (Vanderlinde et al 2019), STARE2 (Bochenek et al 2020a), Galactic Radio Explorer (GReX) (Connor et al 2021), Deep Synoptic Array 2000(DSA-2000 2 , Five-hundred-meter Aperture Spherical Telescope (FAST) (Jiang et al 2019), Green Bank Telescope (GBT) (Connor et al 2016), the Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) (Newburgh et al 2016), MeerKAT (Rajwade et al 2021), Parkes (Petroff et al 2014), Packed Ultra-wideband Mapping Array (PUMA) (Slosar et al 2019), Square Kilometre Array Phase 1 (SKA-1) (Braun et al 2019), SKA-2 (Torchinsky et al 2016), and Very Large Array (VLA) (Law et al 2018).…”

Fast radio bursts at the dawn of the 2020s

“…CHIME/FRB provides daily monitoring of the northern hemisphere, but with only ∼ 10 min integration in the main beams. This can be complemented by low-sensitivity arrays, like STARE2 and the proposed GRex, that are observing (close to) the whole sky simultaneously (Connor et al, 2021), as well as high-cadence observations of known sources using 25-m class radio telescopes (Kirsten et al, 2021a). The Galactic centre and bulge deserve particular attention; high-cadence X-ray monitoring has demonstrated the scientific potential of this approach (Degenaar and Wijnands, 2010).…”

Detection rate of fast radio bursts in the Milky Way with BURSTT

“…The effects of the Interstellar Medium (ISM) on the detection of FRB-like events in the Milky Way are considered when setting up distributions of FRB-like event sources in the Milky Way since pulses travelling through the ISM are scattered as a function of DM (Bhat et al 2004). We then simulate the recently proposed BURSTT experiment to investigate how it probes the Milky Way for bursts and evaluate the performance of BURSTT (Lin et al 2022) over those of STARE2 (Bochenek et al 2020a) and Galactic Radio Explorer (GReX) (Connor et al 2021) in Section 3. STARE2 and GReX are chosen since the comparison of performance between these two surveys has been proposed in the previous paper (Gohar & Flynn 2022).…”