A VLBI Calibrator Grid at 600MHz for Fast Radio Transient Localizations with CHIME/FRB Outriggers

TL;DR

This paper presents a large catalog of compact calibrators at 600MHz for VLBI, enabling precise localization of fast radio bursts with CHIME/FRB Outriggers, based on a wide-area survey using the GBO station.

Contribution

The paper introduces the largest catalog of 200 compact calibrators at sub-GHz frequencies for VLBI, specifically tailored for fast radio burst localization with CHIME/FRB Outriggers.

Findings

Catalog contains 200 calibrators suitable for 30-mas VLBI at 600MHz.

Calibrators are compact with fluxes above 100mJy.

Enables precise localization of hundreds of FRBs annually.

Abstract

The Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) Project has a new VLBI Outrigger at the Green Bank Observatory (GBO), which forms a 3300km baseline with CHIME operating at 400-800MHz. Using 100ms long full-array baseband "snapshots" collected commensally during FRB and pulsar triggers, we perform a shallow, wide-area VLBI survey covering a significant fraction of the Northern sky targeted at the positions of compact sources from the Radio Fundamental Catalog. In addition, our survey contains calibrators detected from two 1s long trial baseband snapshots for a deeper survey with CHIME and GBO. In this paper, we present the largest catalog of compact calibrators suitable for 30-milliarcsecond-scale VLBI observations at sub-GHz frequencies to date. Our catalog consists of 200 total calibrators in the Northern Hemisphere that are compact on 30-milliarcsecond scales with fluxes above 100mJy. This calibrator grid will enable the precise localization of hundreds of FRBs a year with CHIME/FRB-Outriggers.