Localizing FRBs through VLBI with the Algonquin Radio Observatory 10 m Telescope

The Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB experiment has detected thousands of fast radio bursts (FRBs) due to its sensitivity and wide field of view; however, its low angular resolution prevents it from localizing events to their host galaxies. Very long baseline interferometry (VLBI), triggered by FRB detections from CHIME/FRB will solve the challenge of localization for non-repeating events. Using a refurbished 10 m radio dish at the Algonquin Radio Observatory located in Ontario Canada, we developed a testbed for a VLBI experiment with a theoretical lambda/D less than or similar to 30 mas. We provide an overview of the 10 m system and describe its refurbishment, the data acquisition, and a procedure for fringe fitting that simultaneously estimates the geometric delay used for localization and the dispersive delay from the ionosphere. Using single pulses from the Crab pulsar, we validate the system and localization procedure, and analyze the clock stability between sites, which is critical for coherently delay referencing an FRB event. We find a localization of similar to 200 mas is possible with the performance of the current system (single-baseline). Furthermore, for sources with insufficient signal or restricted wideband to simultaneously measure both geometric and ionospheric delays, we show that the differential ionospheric contribution between the two sites must be measured to a precision of 1 x 10(-8) pc cm(-3) to provide a reasonable localization from a detection in the 400-800 MHz band. Finally we show detection of an FRB observed simultaneously in the CHIME and the Algonquin 10 m telescope, the first non-repeating FRB in this long baseline. This project serves as a testbed for the forthcoming CHIME/FRB Outriggers project.

Automated summary

The Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB experiment has successfully detected fast radio bursts (FRBs) with the help of its sensitivity and wide field of view, but its low resolution hinders accurate localization to host galaxies. Very long baseline interferometry (VLBI) can provide a solution to this localization challenge for non-repeating events. By refurbishing a 10 m radio dish at the Algonquin Radio Observatory in Canada, a testbed for VLBI experiments with a resolution of approximately 30 mas has been developed. The system's performance and localization procedure have been validated using single pulses from the Crab pulsar, and the project has successfully detected a non-repeating FRB simultaneously observed in both the CHIME and the Algonquin 10 m telescope.