Extragalactic HI Surveys at Arecibo: the Future

TL;DR

This paper reviews the history and future prospects of extragalactic HI surveys at Arecibo, highlighting technological upgrades like ALFA and the proposed AO40 phased array system to enhance survey speed and scientific capabilities.

Contribution

It introduces the upcoming AO40 phased array system and compares its survey performance to SKA precursors, outlining new scientific survey possibilities.

Findings

ALFA increased survey speed by nearly tenfold.

AO40 could match SKA-precursor survey performance.

New surveys enabled by AO40 are discussed.

Abstract

Starting in the 1970s, the Arecibo 305m telescope has made seminal contributions in the field of extragalactic spectroscopy. With the Gregorian upgrade completed in the late 1990s, the telescope acquired a field of view. Population of that field of view with a seven-feed array at L-band (ALFA) increased by nearly one order of magnitude its survey speed. As a result, much of the extragalactic astronomy time of the telescope is now allocated to survey projects, which are briefly discussed. The next technical development stage for the 305m telescope is foreseen as that of a 40 beam system that would take advantage of phased array technology: AO40. This would further speed up the survey performance of the telescope. It is shown how the figure of merit for survey speed of AO40 would be comparable with that of SKA-precursor facilities, planned for operation in the next decade. A number of scientifically desirable new surveys that would become possible with AO40 are briefly discussed.