GBT26A-457

Unveiling FRBs in Galaxy Clusters: A GREENBURST Census

Abstract

We propose a targeted search for Fast Radio Bursts (FRBs) within galaxy clusters at moderate redshifts using the GBT and the GREENBURST real-time FRB detection system. FRBs are enigmatic cosmological sources, offering unique probes of the Universe's large-scale structure and the intergalactic medium (IGM). Recent discoveries of FRBs associated with diverse host galaxy environments, including galaxy clusters, highlight the need to systematically investigate these dense regions. GREENBURST has so far successfully identified FRBs and pulsars during its 21,000 hours of operation.

Building on the detection of FRB 20240817A, we request 33 hours of dedicated GBT time to observe five high-declination galaxy clusters. This pilot study aims to maximize the number of target galaxies per observation and leverage the GBT's high sensitivity. Detecting even a single FRB consistent with a cluster association would provide strong statistical constraints on its origin and allow for dispersion measure (DM) and rotation measure (RM) studies of the intracluster medium (ICM). This targeted approach complements ongoing blind surveys and will inform future, more extensive investigations with array-based instruments, ultimately advancing our understanding of FRB progenitors and their environments. The proposed observations are also sensitive to gravitationally lensed FRBs in the background of the target clusters.

Investigators

Name	Institution
Dunc Lorimer *	West Virginia University
Maura McLaughlin	West Virginia University
Conor Larison	Space Telescope Science Institute

* indicates the PI