The Expanded Very Large Array -- a New Telescope for New Science

TL;DR

The paper discusses the upgrade of the Very Large Array to the EVLA, significantly enhancing its sensitivity, frequency coverage, and flexibility, enabling new scientific discoveries with a modernized radio telescope.

Contribution

It introduces the EVLA upgrade, detailing its goals, current status, and expanded capabilities compared to the original VLA.

Findings

Complete frequency coverage from 1 to 50 GHz

Continuum sensitivity of about 1 microJy/beam in 9 hours

Enhanced correlator capabilities and flexibility

Abstract

Since its commissioning in 1980, the Very Large Array (VLA) has consistently demonstrated its scientific productivity. However, its fundamental capabilities have changed little since 1980, particularly in the key areas of sensitivity, frequency coverage, and velocity resolution. These limitations have been addressed by a major upgrade of the array, which began in 2001 and will be completed at the end of 2012. When completed, the Expanded VLA -- the EVLA -- will provide complete frequency coverage from 1 to 50 GHz, a continuum sensitivity of typically 1 microJy/beam (in 9 hours with full bandwidth), and a modern correlator with vastly greater capabilities and flexibility than the VLA's. In this paper we describe the goals of the EVLA project, its current status, and the anticipated expansion of capabilities over the next few years. User access to the array through the OSRO and RSRO programs is described. The following papers in this special issue, derived from observations in its early science period, demonstrate the astonishing breadth of this most flexible and powerful general-purpose telescope.