THE EXPANDED VERY LARGE ARRAY: A NEW TELESCOPE FOR NEW SCIENCE

Abstract

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