A wider audience: Turning VLBI into a survey instrument

TL;DR

Recent technological advances have transformed VLBI from a targeted, narrow-field technique into a powerful wide-field survey instrument capable of observing nearly any sky point with high resolution.

Contribution

The paper reviews recent developments in wide-field VLBI, highlighting technological improvements that enable large-scale, sensitive, high-resolution sky surveys.

Findings

Wide-field VLBI now capable of surveying almost any sky point.

Technological advances have increased sensitivity and computational capacity.

Progress over the last three years significantly expanded VLBI survey capabilities.

Abstract

Radio observations using the Very Long Baseline Interferometry (VLBI) technique typically have fields of view of only a few arcseconds, due to the computational problems inherent in imaging larger fields. Furthermore, sensitivity limitations restrict observations to very compact and bright objects, which are few and far between on the sky. Thus, while most branches of observational astronomy can carry out sensitive, wide-field surveys, VLBI observations are limited to targeted observations of carefully selected objects. However, recent advances in technology have made it possible to carry out the computations required to target hundreds of sources simultaneously. Furthermore, sensitivity upgrades have dramatically increased the number of objects accessible to VLBI observations. The combination of these two developments have enhanced the survey capabilities of VLBI observations such that it is now possible to observe (almost) any point in the sky with milli-arcsecond resolution. In this talk I review the development of wide-field VLBI, which has made significant progress over the last three years.