A VLBI Calibration System with Real-time Pulsar Gating for FRB Localization using CHIME/FRB Outriggers

Several thousand fast radio burst (FRB) sources have been discovered using the Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope, as part of the CHIME/FRB project. Currently, CHIME/FRB is able to localize most FRBs to a limiting precision of several arcminutes, which can be improved to subarcminute precision for some FRB sources through offline analysis of their baseband data. This allows only the most nearby sources to be robustly associated with a host galaxy. Using three new Outrigger telescopes located at transcontinental distances from CHIME, the CHIME/FRB Outriggers project will improve the localization capabilities of CHIME/FRB. Together, these radio telescopes will form a wide field of view, very long baseline interferometry (VLBI) array that will enable FRBs discovered by CHIME/FRB to be localized to a limiting precision of ~50 milliarcseconds. The astrometric position of each FRB will be determined using calibration solutions derived from well-localized radio pulsars and compact, steady radio sources. We present an overview of the VLBI calibration system that will be employed within the CHIME/FRB Outrigger project to achieve high precision FRB localizations, which will enable studies of a large number of FRB host galaxies and local environments.