Deep Synoptic Array Science: First FRB and Host Galaxy Catalog

Abstract

Fast radio bursts (FRBs) are a powerful and mysterious new class of transients that are luminous enough to be detected at cosmological distances. By associating FRBs to host galaxies, we can measure intrinsic and environmental properties that test FRB origin models, in addition to using them as precise probes of distant cosmic gas. The Deep Synoptic Array (DSA-110) is a radio interferometer built to maximize the rate at which it can simultaneously detect and localize FRBs. Here, we present the first sample of FRBs and host galaxies discovered by the DSA-110. This sample of 11 FRBs is the largest, most uniform sample of localized FRBs to date, as it is selected based on association with host galaxies identified in optical imaging by Pan-STARRS1. These FRBs have not been observed to repeat, and their radio properties (dispersion, temporal scattering, energy) are similar to that of the known nonrepeating FRB population. Most host galaxies have ongoing star formation, as has been identified before for FRB hosts. Two hosts of the new sample are massive, quiescent galaxies. The distribution of star formation history across this host-galaxy sample shows that the delay time distribution is wide, with a power-law model that spans from ∼100 Myr to ≳2 Gyr. This requires the existence of one or more progenitor formation channels associated with old stellar populations, such as the binary evolution of compact objects.

The Curious Case of Twin Fast Radio Bursts: Evidence for Neutron Star Origin?

“…This compares to the small fraction (≈2%) of known pulsars that show interpulse emission-evidence for emission from both poles-but with faster-spinning pulsars having a greater prevalence for interpulses (e.g., Kramer et al 1998;Weltevrede & Johnston 2008;Keith et al 2010). A thorough search for similar events in other FRB surveys (e.g., CHIME/FRB Collaboration et al 2021;Law et al 2024) is beyond the scope of this work.…”

“…Fast radio bursts (FRBs; e.g., Lorimer et al 2007;Thornton et al 2013) are intense short-lived radio signals of cosmological origin, the progenitors of which remain unknown to date (e.g., Petroff et al 2022). There have been a plethora of FRB observations since their discovery (e.g., Shannon et al 2018;CHIME/FRB Collaboration et al 2021;Law et al 2024), which have revealed a vast diversity of burst profiles (e.g., Pleunis et al 2021), polarization properties (e.g., Day et al 2020), host galaxies (e.g., Bhandari et al 2022), and local magneto-ionic environments (e.g., Mannings et al 2021;Mckinven et al 2023). This diversity makes it difficult to infer progenitor properties, especially when allowing for selection biases (Macquart & Ekers 2018), effects of propagation through ionized media on the observed burst properties (e.g., Petroff et al 2022), and the possibility of multiple progenitor populations (e.g., Caleb et al 2018).…”

CHIME/FRB Outriggers: KKO Station System and Commissioning Results

“…Mannings et al (2021) compared the distribution of offsets to other transients, disfavoring long gamma-ray burst models and favoring formation channels similar to core-collapse supernovae and binary neutron star mergers. The Deep Synoptic Array 110 recently put out its first uniform sample of FRB host galaxies, which the authors argue supports progenitor formation channels associated with old stellar populations (Law et al 2024;Ravi et al 2023). Sub-kiloparsec-scale localization has been achieved with very long baseline interferometry (VLBI) observations of some repeating FRBs, showing a variety of host environments.…”